| Message ID | 1580185137-11255-1-git-send-email-gupt21@gmail.com (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 4f8a21a6a9335fdf0952af3cadfa88c33dddacd6 |
| Headers | show |
| Series | [v3] HID: mcp2221: add usb to i2c-smbus host bridge | expand |
Humble request for review (all suggestions addressed & tested). GPIO support is also ready, once this patch is Acknowledged I will submit that also. Regards, Rishi On Tue, Jan 28, 2020 at 9:49 AM Rishi Gupta <gupt21@gmail.com> wrote: > > MCP2221 is a USB HID to I2C/SMbus host bridge device. This > commit implements i2c and smbus host adapter support. 7-bit > address and i2c multi-message transaction is also supported. > > Signed-off-by: Rishi Gupta <gupt21@gmail.com> > --- > > Changes in v3: > * Removed all direct USB related references > * Replaced defines with enum > * Replaced HID_CONNECT_DEFAULT with HID_CONNECT_HIDRAW > * Removed depends on HIDRAW in Kconfig > * Used memset wherever possible > * Emit more clear log - unsupported multi-msg i2c transaction > * Removed mcp2221 entry from hid-quirk.c > * Removed module parameter to set i2c bus speed > > MAINTAINERS | 7 + > drivers/hid/Kconfig | 10 + > drivers/hid/Makefile | 1 + > drivers/hid/hid-ids.h | 1 + > drivers/hid/hid-mcp2221.c | 742 ++++++++++++++++++++++++++++++++++++++++++++++ > 5 files changed, 761 insertions(+) > create mode 100644 drivers/hid/hid-mcp2221.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index 141b8d3..bfcdd55 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -10160,6 +10160,13 @@ F: drivers/net/can/m_can/m_can.c > F: drivers/net/can/m_can/m_can.h > F: drivers/net/can/m_can/m_can_platform.c > > +MCP2221A MICROCHIP USB-HID TO I2C BRIDGE DRIVER > +M: Rishi Gupta <gupt21@gmail.com> > +L: linux-i2c@vger.kernel.org > +L: linux-input@vger.kernel.org > +S: Maintained > +F: drivers/hid/hid-mcp2221.c > + > MCP4018 AND MCP4531 MICROCHIP DIGITAL POTENTIOMETER DRIVERS > M: Peter Rosin <peda@axentia.se> > L: linux-iio@vger.kernel.org > diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig > index 494a39e..5db6e6a 100644 > --- a/drivers/hid/Kconfig > +++ b/drivers/hid/Kconfig > @@ -1145,6 +1145,16 @@ config HID_ALPS > Say Y here if you have a Alps touchpads over i2c-hid or usbhid > and want support for its special functionalities. > > +config HID_MCP2221 > + tristate "Microchip MCP2221 HID USB-to-I2C/SMbus host support" > + depends on USB_HID && I2C > + ---help--- > + Provides I2C and SMBUS host adapter functionality over USB-HID > + through MCP2221 device. > + > + To compile this driver as a module, choose M here: the module > + will be called hid-mcp2221.ko. > + > endmenu > > endif # HID > diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile > index bfefa36..21052a7 100644 > --- a/drivers/hid/Makefile > +++ b/drivers/hid/Makefile > @@ -70,6 +70,7 @@ obj-$(CONFIG_HID_LOGITECH_HIDPP) += hid-logitech-hidpp.o > obj-$(CONFIG_HID_MACALLY) += hid-macally.o > obj-$(CONFIG_HID_MAGICMOUSE) += hid-magicmouse.o > obj-$(CONFIG_HID_MALTRON) += hid-maltron.o > +obj-$(CONFIG_HID_MCP2221) += hid-mcp2221.o > obj-$(CONFIG_HID_MAYFLASH) += hid-mf.o > obj-$(CONFIG_HID_MICROSOFT) += hid-microsoft.o > obj-$(CONFIG_HID_MONTEREY) += hid-monterey.o > diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h > index 3a400ce..53236ac 100644 > --- a/drivers/hid/hid-ids.h > +++ b/drivers/hid/hid-ids.h > @@ -819,6 +819,7 @@ > #define USB_DEVICE_ID_PICK16F1454 0x0042 > #define USB_DEVICE_ID_PICK16F1454_V2 0xf2f7 > #define USB_DEVICE_ID_LUXAFOR 0xf372 > +#define USB_DEVICE_ID_MCP2221 0x00dd > > #define USB_VENDOR_ID_MICROSOFT 0x045e > #define USB_DEVICE_ID_SIDEWINDER_GV 0x003b > diff --git a/drivers/hid/hid-mcp2221.c b/drivers/hid/hid-mcp2221.c > new file mode 100644 > index 0000000..d958475 > --- /dev/null > +++ b/drivers/hid/hid-mcp2221.c > @@ -0,0 +1,742 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * MCP2221A - Microchip USB to I2C Host Protocol Bridge > + * > + * Copyright (c) 2020, Rishi Gupta <gupt21@gmail.com> > + * > + * Datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/20005565B.pdf > + */ > + > +#include <linux/module.h> > +#include <linux/err.h> > +#include <linux/mutex.h> > +#include <linux/completion.h> > +#include <linux/delay.h> > +#include <linux/hid.h> > +#include <linux/hidraw.h> > +#include <linux/i2c.h> > +#include "hid-ids.h" > + > +/* Commands codes in a raw output report */ > +enum { > + MCP2221_I2C_WR_DATA = 0x90, > + MCP2221_I2C_WR_NO_STOP = 0x94, > + MCP2221_I2C_RD_DATA = 0x91, > + MCP2221_I2C_RD_RPT_START = 0x93, > + MCP2221_I2C_GET_DATA = 0x40, > + MCP2221_I2C_PARAM_OR_STATUS = 0x10, > + MCP2221_I2C_SET_SPEED = 0x20, > + MCP2221_I2C_CANCEL = 0x10, > +}; > + > +/* Response codes in a raw input report */ > +enum { > + MCP2221_SUCCESS = 0x00, > + MCP2221_I2C_ENG_BUSY = 0x01, > + MCP2221_I2C_START_TOUT = 0x12, > + MCP2221_I2C_STOP_TOUT = 0x62, > + MCP2221_I2C_WRADDRL_TOUT = 0x23, > + MCP2221_I2C_WRDATA_TOUT = 0x44, > + MCP2221_I2C_WRADDRL_NACK = 0x25, > + MCP2221_I2C_MASK_ADDR_NACK = 0x40, > + MCP2221_I2C_WRADDRL_SEND = 0x21, > + MCP2221_I2C_ADDR_NACK = 0x25, > + MCP2221_I2C_READ_COMPL = 0x55, > +}; > + > +/* > + * There is no way to distinguish responses. Therefore next command > + * is sent only after response to previous has been received. Mutex > + * lock is used for this purpose mainly. > + */ > +struct mcp2221 { > + struct hid_device *hdev; > + struct i2c_adapter adapter; > + struct mutex lock; > + struct completion wait_in_report; > + u8 *rxbuf; > + u8 txbuf[64]; > + int rxbuf_idx; > + int status; > + u8 cur_i2c_clk_div; > +}; > + > +/* > + * Default i2c bus clock frequency 400 kHz. Modify this if you > + * want to set some other frequency (min 50 kHz - max 400 kHz). > + */ > +static uint i2c_clk_freq = 400; > + > +/* Synchronously send output report to the device */ > +static int mcp_send_report(struct mcp2221 *mcp, > + u8 *out_report, size_t len) > +{ > + u8 *buf; > + int ret; > + > + buf = kmemdup(out_report, len, GFP_KERNEL); > + if (!buf) > + return -ENOMEM; > + > + /* mcp2221 uses interrupt endpoint for out reports */ > + ret = hid_hw_output_report(mcp->hdev, buf, len); > + kfree(buf); > + > + if (ret < 0) > + return ret; > + return 0; > +} > + > +/* > + * Send o/p report to the device and wait for i/p report to be > + * received from the device. If the device does not respond, > + * we timeout. > + */ > +static int mcp_send_data_req_status(struct mcp2221 *mcp, > + u8 *out_report, int len) > +{ > + int ret; > + unsigned long t; > + > + reinit_completion(&mcp->wait_in_report); > + > + ret = mcp_send_report(mcp, out_report, len); > + if (ret) > + return ret; > + > + t = wait_for_completion_timeout(&mcp->wait_in_report, > + msecs_to_jiffies(4000)); > + if (!t) > + return -ETIMEDOUT; > + > + return mcp->status; > +} > + > +/* Check pass/fail for actual communication with i2c slave */ > +static int mcp_chk_last_cmd_status(struct mcp2221 *mcp) > +{ > + memset(mcp->txbuf, 0, 8); > + mcp->txbuf[0] = MCP2221_I2C_PARAM_OR_STATUS; > + > + return mcp_send_data_req_status(mcp, mcp->txbuf, 8); > +} > + > +/* Cancels last command releasing i2c bus just in case occupied */ > +static int mcp_cancel_last_cmd(struct mcp2221 *mcp) > +{ > + memset(mcp->txbuf, 0, 8); > + mcp->txbuf[0] = MCP2221_I2C_PARAM_OR_STATUS; > + mcp->txbuf[2] = MCP2221_I2C_CANCEL; > + > + return mcp_send_data_req_status(mcp, mcp->txbuf, 8); > +} > + > +static int mcp_set_i2c_speed(struct mcp2221 *mcp) > +{ > + int ret; > + > + memset(mcp->txbuf, 0, 8); > + mcp->txbuf[0] = MCP2221_I2C_PARAM_OR_STATUS; > + mcp->txbuf[3] = MCP2221_I2C_SET_SPEED; > + mcp->txbuf[4] = mcp->cur_i2c_clk_div; > + > + ret = mcp_send_data_req_status(mcp, mcp->txbuf, 8); > + if (ret) { > + /* Small delay is needed here */ > + usleep_range(980, 1000); > + mcp_cancel_last_cmd(mcp); > + } > + > + return 0; > +} > + > +/* > + * An output report can contain minimum 1 and maximum 60 user data > + * bytes. If the number of data bytes is more then 60, we send it > + * in chunks of 60 bytes. Last chunk may contain exactly 60 or less > + * bytes. Total number of bytes is informed in very first report to > + * mcp2221, from that point onwards it first collect all the data > + * from host and then send to i2c slave device. > + */ > +static int mcp_i2c_write(struct mcp2221 *mcp, > + struct i2c_msg *msg, int type, u8 last_status) > +{ > + int ret, len, idx, sent; > + > + idx = 0; > + sent = 0; > + if (msg->len < 60) > + len = msg->len; > + else > + len = 60; > + > + do { > + mcp->txbuf[0] = type; > + mcp->txbuf[1] = msg->len & 0xff; > + mcp->txbuf[2] = msg->len >> 8; > + mcp->txbuf[3] = (u8)(msg->addr << 1); > + > + memcpy(&mcp->txbuf[4], &msg->buf[idx], len); > + > + ret = mcp_send_data_req_status(mcp, mcp->txbuf, len + 4); > + if (ret) > + return ret; > + > + usleep_range(980, 1000); > + > + if (last_status) { > + ret = mcp_chk_last_cmd_status(mcp); > + if (ret) > + return ret; > + } > + > + sent = sent + len; > + if (sent >= msg->len) > + break; > + > + idx = idx + len; > + if ((msg->len - sent) < 60) > + len = msg->len - sent; > + else > + len = 60; > + > + /* > + * Testing shows delay is needed between successive writes > + * otherwise next write fails on first-try from i2c core. > + * This value is obtained through automated stress testing. > + */ > + usleep_range(980, 1000); > + } while (len > 0); > + > + return ret; > +} > + > +/* > + * Device reads all data (0 - 65535 bytes) from i2c slave device and > + * stores it in device itself. This data is read back from device to > + * host in multiples of 60 bytes using input reports. > + */ > +static int mcp_i2c_smbus_read(struct mcp2221 *mcp, > + struct i2c_msg *msg, int type, u16 smbus_addr, > + u8 smbus_len, u8 *smbus_buf) > +{ > + int ret; > + u16 total_len; > + > + mcp->txbuf[0] = type; > + if (msg) { > + mcp->txbuf[1] = msg->len & 0xff; > + mcp->txbuf[2] = msg->len >> 8; > + mcp->txbuf[3] = (u8)(msg->addr << 1); > + total_len = msg->len; > + mcp->rxbuf = msg->buf; > + } else { > + mcp->txbuf[1] = smbus_len; > + mcp->txbuf[2] = 0; > + mcp->txbuf[3] = (u8)(smbus_addr << 1); > + total_len = smbus_len; > + mcp->rxbuf = smbus_buf; > + } > + > + ret = mcp_send_data_req_status(mcp, mcp->txbuf, 4); > + if (ret) > + return ret; > + > + mcp->rxbuf_idx = 0; > + > + do { > + memset(mcp->txbuf, 0, 4); > + mcp->txbuf[0] = MCP2221_I2C_GET_DATA; > + > + ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1); > + if (ret) > + return ret; > + > + ret = mcp_chk_last_cmd_status(mcp); > + if (ret) > + return ret; > + > + usleep_range(980, 1000); > + } while (mcp->rxbuf_idx < total_len); > + > + return ret; > +} > + > +static int mcp_i2c_xfer(struct i2c_adapter *adapter, > + struct i2c_msg msgs[], int num) > +{ > + int ret; > + struct mcp2221 *mcp = i2c_get_adapdata(adapter); > + > + hid_hw_power(mcp->hdev, PM_HINT_FULLON); > + > + mutex_lock(&mcp->lock); > + > + /* Setting speed before every transaction is required for mcp2221 */ > + ret = mcp_set_i2c_speed(mcp); > + if (ret) > + goto exit; > + > + if (num == 1) { > + if (msgs->flags & I2C_M_RD) { > + ret = mcp_i2c_smbus_read(mcp, msgs, MCP2221_I2C_RD_DATA, > + 0, 0, NULL); > + } else { > + ret = mcp_i2c_write(mcp, msgs, MCP2221_I2C_WR_DATA, 1); > + } > + if (ret) > + goto exit; > + ret = num; > + } else if (num == 2) { > + /* Ex transaction; send reg address and read its contents */ > + if (msgs[0].addr == msgs[1].addr && > + !(msgs[0].flags & I2C_M_RD) && > + (msgs[1].flags & I2C_M_RD)) { > + > + ret = mcp_i2c_write(mcp, &msgs[0], > + MCP2221_I2C_WR_NO_STOP, 0); > + if (ret) > + goto exit; > + > + ret = mcp_i2c_smbus_read(mcp, &msgs[1], > + MCP2221_I2C_RD_RPT_START, > + 0, 0, NULL); > + if (ret) > + goto exit; > + ret = num; > + } else { > + dev_err(&adapter->dev, > + "unsupported multi-msg i2c transaction\n"); > + ret = -EOPNOTSUPP; > + } > + } else { > + dev_err(&adapter->dev, > + "unsupported multi-msg i2c transaction\n"); > + ret = -EOPNOTSUPP; > + } > + > +exit: > + hid_hw_power(mcp->hdev, PM_HINT_NORMAL); > + mutex_unlock(&mcp->lock); > + return ret; > +} > + > +static int mcp_smbus_write(struct mcp2221 *mcp, u16 addr, > + u8 command, u8 *buf, u8 len, int type, > + u8 last_status) > +{ > + int data_len, ret; > + > + mcp->txbuf[0] = type; > + mcp->txbuf[1] = len + 1; /* 1 is due to command byte itself */ > + mcp->txbuf[2] = 0; > + mcp->txbuf[3] = (u8)(addr << 1); > + mcp->txbuf[4] = command; > + > + switch (len) { > + case 0: > + data_len = 5; > + break; > + case 1: > + mcp->txbuf[5] = buf[0]; > + data_len = 6; > + break; > + case 2: > + mcp->txbuf[5] = buf[0]; > + mcp->txbuf[6] = buf[1]; > + data_len = 7; > + break; > + default: > + memcpy(&mcp->txbuf[5], buf, len); > + data_len = len + 5; > + } > + > + ret = mcp_send_data_req_status(mcp, mcp->txbuf, data_len); > + if (ret) > + return ret; > + > + if (last_status) { > + usleep_range(980, 1000); > + > + ret = mcp_chk_last_cmd_status(mcp); > + if (ret) > + return ret; > + } > + > + return ret; > +} > + > +static int mcp_smbus_xfer(struct i2c_adapter *adapter, u16 addr, > + unsigned short flags, char read_write, > + u8 command, int size, > + union i2c_smbus_data *data) > +{ > + int ret; > + struct mcp2221 *mcp = i2c_get_adapdata(adapter); > + > + hid_hw_power(mcp->hdev, PM_HINT_FULLON); > + > + mutex_lock(&mcp->lock); > + > + ret = mcp_set_i2c_speed(mcp); > + if (ret) > + goto exit; > + > + switch (size) { > + > + case I2C_SMBUS_QUICK: > + if (read_write == I2C_SMBUS_READ) > + ret = mcp_i2c_smbus_read(mcp, NULL, MCP2221_I2C_RD_DATA, > + addr, 0, &data->byte); > + else > + ret = mcp_smbus_write(mcp, addr, command, NULL, > + 0, MCP2221_I2C_WR_DATA, 1); > + break; > + case I2C_SMBUS_BYTE: > + if (read_write == I2C_SMBUS_READ) > + ret = mcp_i2c_smbus_read(mcp, NULL, MCP2221_I2C_RD_DATA, > + addr, 1, &data->byte); > + else > + ret = mcp_smbus_write(mcp, addr, command, NULL, > + 0, MCP2221_I2C_WR_DATA, 1); > + break; > + case I2C_SMBUS_BYTE_DATA: > + if (read_write == I2C_SMBUS_READ) { > + ret = mcp_smbus_write(mcp, addr, command, NULL, > + 0, MCP2221_I2C_WR_NO_STOP, 0); > + if (ret) > + goto exit; > + > + ret = mcp_i2c_smbus_read(mcp, NULL, > + MCP2221_I2C_RD_RPT_START, > + addr, 1, &data->byte); > + } else { > + ret = mcp_smbus_write(mcp, addr, command, &data->byte, > + 1, MCP2221_I2C_WR_DATA, 1); > + } > + break; > + case I2C_SMBUS_WORD_DATA: > + if (read_write == I2C_SMBUS_READ) { > + ret = mcp_smbus_write(mcp, addr, command, NULL, > + 0, MCP2221_I2C_WR_NO_STOP, 0); > + if (ret) > + goto exit; > + > + ret = mcp_i2c_smbus_read(mcp, NULL, > + MCP2221_I2C_RD_RPT_START, > + addr, 2, (u8 *)&data->word); > + } else { > + ret = mcp_smbus_write(mcp, addr, command, > + (u8 *)&data->word, 2, > + MCP2221_I2C_WR_DATA, 1); > + } > + break; > + case I2C_SMBUS_BLOCK_DATA: > + if (read_write == I2C_SMBUS_READ) { > + ret = mcp_smbus_write(mcp, addr, command, NULL, > + 0, MCP2221_I2C_WR_NO_STOP, 1); > + if (ret) > + goto exit; > + > + mcp->rxbuf_idx = 0; > + mcp->rxbuf = data->block; > + mcp->txbuf[0] = MCP2221_I2C_GET_DATA; > + ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1); > + if (ret) > + goto exit; > + } else { > + if (!data->block[0]) { > + ret = -EINVAL; > + goto exit; > + } > + ret = mcp_smbus_write(mcp, addr, command, data->block, > + data->block[0] + 1, > + MCP2221_I2C_WR_DATA, 1); > + } > + break; > + case I2C_SMBUS_I2C_BLOCK_DATA: > + if (read_write == I2C_SMBUS_READ) { > + ret = mcp_smbus_write(mcp, addr, command, NULL, > + 0, MCP2221_I2C_WR_NO_STOP, 1); > + if (ret) > + goto exit; > + > + mcp->rxbuf_idx = 0; > + mcp->rxbuf = data->block; > + mcp->txbuf[0] = MCP2221_I2C_GET_DATA; > + ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1); > + if (ret) > + goto exit; > + } else { > + if (!data->block[0]) { > + ret = -EINVAL; > + goto exit; > + } > + ret = mcp_smbus_write(mcp, addr, command, > + &data->block[1], data->block[0], > + MCP2221_I2C_WR_DATA, 1); > + } > + break; > + case I2C_SMBUS_PROC_CALL: > + ret = mcp_smbus_write(mcp, addr, command, > + (u8 *)&data->word, > + 2, MCP2221_I2C_WR_NO_STOP, 0); > + if (ret) > + goto exit; > + > + ret = mcp_i2c_smbus_read(mcp, NULL, > + MCP2221_I2C_RD_RPT_START, > + addr, 2, (u8 *)&data->word); > + break; > + case I2C_SMBUS_BLOCK_PROC_CALL: > + ret = mcp_smbus_write(mcp, addr, command, data->block, > + data->block[0] + 1, > + MCP2221_I2C_WR_NO_STOP, 0); > + if (ret) > + goto exit; > + > + ret = mcp_i2c_smbus_read(mcp, NULL, > + MCP2221_I2C_RD_RPT_START, > + addr, I2C_SMBUS_BLOCK_MAX, > + data->block); > + break; > + default: > + dev_err(&mcp->adapter.dev, > + "unsupported smbus transaction size:%d\n", size); > + ret = -EOPNOTSUPP; > + } > + > +exit: > + hid_hw_power(mcp->hdev, PM_HINT_NORMAL); > + mutex_unlock(&mcp->lock); > + return ret; > +} > + > +static u32 mcp_i2c_func(struct i2c_adapter *adapter) > +{ > + return I2C_FUNC_I2C | > + I2C_FUNC_SMBUS_READ_BLOCK_DATA | > + I2C_FUNC_SMBUS_BLOCK_PROC_CALL | > + (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_PEC); > +} > + > +static const struct i2c_algorithm mcp_i2c_algo = { > + .master_xfer = mcp_i2c_xfer, > + .smbus_xfer = mcp_smbus_xfer, > + .functionality = mcp_i2c_func, > +}; > + > +/* Gives current state of i2c engine inside mcp2221 */ > +static int mcp_get_i2c_eng_state(struct mcp2221 *mcp, > + u8 *data, u8 idx) > +{ > + int ret; > + > + switch (data[idx]) { > + case MCP2221_I2C_WRADDRL_NACK: > + case MCP2221_I2C_WRADDRL_SEND: > + ret = -ENXIO; > + break; > + case MCP2221_I2C_START_TOUT: > + case MCP2221_I2C_STOP_TOUT: > + case MCP2221_I2C_WRADDRL_TOUT: > + case MCP2221_I2C_WRDATA_TOUT: > + ret = -ETIMEDOUT; > + break; > + case MCP2221_I2C_ENG_BUSY: > + ret = -EAGAIN; > + break; > + case MCP2221_SUCCESS: > + ret = 0x00; > + break; > + default: > + ret = -EIO; > + } > + > + return ret; > +} > + > +/* > + * MCP2221 uses interrupt endpoint for input reports. This function > + * is called by HID layer when it receives i/p report from mcp2221, > + * which is actually a response to the previously sent command. > + * > + * MCP2221A firmware specific return codes are parsed and 0 or > + * appropriate negative error code is returned. Delayed response > + * results in timeout error and stray reponses results in -EIO. > + */ > +static int mcp2221_raw_event(struct hid_device *hdev, > + struct hid_report *report, u8 *data, int size) > +{ > + u8 *buf; > + struct mcp2221 *mcp = hid_get_drvdata(hdev); > + > + switch (data[0]) { > + > + case MCP2221_I2C_WR_DATA: > + case MCP2221_I2C_WR_NO_STOP: > + case MCP2221_I2C_RD_DATA: > + case MCP2221_I2C_RD_RPT_START: > + switch (data[1]) { > + case MCP2221_SUCCESS: > + mcp->status = 0; > + break; > + default: > + mcp->status = mcp_get_i2c_eng_state(mcp, data, 2); > + } > + complete(&mcp->wait_in_report); > + break; > + > + case MCP2221_I2C_PARAM_OR_STATUS: > + switch (data[1]) { > + case MCP2221_SUCCESS: > + if ((mcp->txbuf[3] == MCP2221_I2C_SET_SPEED) && > + (data[3] != MCP2221_I2C_SET_SPEED)) { > + mcp->status = -EAGAIN; > + break; > + } > + if (data[20] & MCP2221_I2C_MASK_ADDR_NACK) { > + mcp->status = -ENXIO; > + break; > + } > + mcp->status = mcp_get_i2c_eng_state(mcp, data, 8); > + break; > + default: > + mcp->status = -EIO; > + } > + complete(&mcp->wait_in_report); > + break; > + > + case MCP2221_I2C_GET_DATA: > + switch (data[1]) { > + case MCP2221_SUCCESS: > + if (data[2] == MCP2221_I2C_ADDR_NACK) { > + mcp->status = -ENXIO; > + break; > + } > + if (!mcp_get_i2c_eng_state(mcp, data, 2) > + && (data[3] == 0)) { > + mcp->status = 0; > + break; > + } > + if (data[3] == 127) { > + mcp->status = -EIO; > + break; > + } > + if (data[2] == MCP2221_I2C_READ_COMPL) { > + buf = mcp->rxbuf; > + memcpy(&buf[mcp->rxbuf_idx], &data[4], data[3]); > + mcp->rxbuf_idx = mcp->rxbuf_idx + data[3]; > + mcp->status = 0; > + break; > + } > + mcp->status = -EIO; > + break; > + default: > + mcp->status = -EIO; > + } > + complete(&mcp->wait_in_report); > + break; > + > + default: > + mcp->status = -EIO; > + complete(&mcp->wait_in_report); > + } > + > + return 1; > +} > + > +static int mcp2221_probe(struct hid_device *hdev, > + const struct hid_device_id *id) > +{ > + int ret; > + struct mcp2221 *mcp; > + > + mcp = devm_kzalloc(&hdev->dev, sizeof(*mcp), GFP_KERNEL); > + if (!mcp) > + return -ENOMEM; > + > + ret = hid_parse(hdev); > + if (ret) { > + hid_err(hdev, "can't parse reports\n"); > + return ret; > + } > + > + ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW); > + if (ret) { > + hid_err(hdev, "can't start hardware\n"); > + return ret; > + } > + > + ret = hid_hw_open(hdev); > + if (ret) { > + hid_err(hdev, "can't open device\n"); > + goto err_hstop; > + } > + > + mutex_init(&mcp->lock); > + init_completion(&mcp->wait_in_report); > + hid_set_drvdata(hdev, mcp); > + mcp->hdev = hdev; > + > + /* Set I2C bus clock diviser */ > + if (i2c_clk_freq > 400) > + i2c_clk_freq = 400; > + if (i2c_clk_freq < 50) > + i2c_clk_freq = 50; > + mcp->cur_i2c_clk_div = (12000000 / (i2c_clk_freq * 1000)) - 3; > + > + mcp->adapter.owner = THIS_MODULE; > + mcp->adapter.class = I2C_CLASS_HWMON; > + mcp->adapter.algo = &mcp_i2c_algo; > + mcp->adapter.retries = 1; > + mcp->adapter.dev.parent = &hdev->dev; > + snprintf(mcp->adapter.name, sizeof(mcp->adapter.name), > + "MCP2221 usb-i2c bridge on hidraw%d", > + ((struct hidraw *)hdev->hidraw)->minor); > + > + ret = i2c_add_adapter(&mcp->adapter); > + if (ret) { > + hid_err(hdev, "can't add usb-i2c adapter: %d\n", ret); > + goto err_i2c; > + } > + i2c_set_adapdata(&mcp->adapter, mcp); > + > + return 0; > + > +err_i2c: > + hid_hw_close(mcp->hdev); > +err_hstop: > + hid_hw_stop(mcp->hdev); > + return ret; > +} > + > +static void mcp2221_remove(struct hid_device *hdev) > +{ > + struct mcp2221 *mcp = hid_get_drvdata(hdev); > + > + i2c_del_adapter(&mcp->adapter); > + hid_hw_close(mcp->hdev); > + hid_hw_stop(mcp->hdev); > +} > + > +static const struct hid_device_id mcp2221_devices[] = { > + { HID_USB_DEVICE(USB_VENDOR_ID_MICROCHIP, USB_DEVICE_ID_MCP2221) }, > + { } > +}; > +MODULE_DEVICE_TABLE(hid, mcp2221_devices); > + > +static struct hid_driver mcp2221_driver = { > + .name = "mcp2221", > + .id_table = mcp2221_devices, > + .probe = mcp2221_probe, > + .remove = mcp2221_remove, > + .raw_event = mcp2221_raw_event, > +}; > + > +/* Register with HID core */ > +module_hid_driver(mcp2221_driver); > + > +MODULE_AUTHOR("Rishi Gupta <gupt21@gmail.com>"); > +MODULE_DESCRIPTION("MCP2221 Microchip HID USB to I2C master bridge"); > +MODULE_LICENSE("GPL v2"); > -- > 2.7.4 >
Gentle ping... Regards, Rishi On Mon, Feb 10, 2020 at 7:20 PM rishi gupta <gupt21@gmail.com> wrote: > > Humble request for review (all suggestions addressed & tested). > GPIO support is also ready, once this patch is Acknowledged I will > submit that also. > > Regards, > Rishi > > On Tue, Jan 28, 2020 at 9:49 AM Rishi Gupta <gupt21@gmail.com> wrote: > > > > MCP2221 is a USB HID to I2C/SMbus host bridge device. This > > commit implements i2c and smbus host adapter support. 7-bit > > address and i2c multi-message transaction is also supported. > > > > Signed-off-by: Rishi Gupta <gupt21@gmail.com> > > --- > > > > Changes in v3: > > * Removed all direct USB related references > > * Replaced defines with enum > > * Replaced HID_CONNECT_DEFAULT with HID_CONNECT_HIDRAW > > * Removed depends on HIDRAW in Kconfig > > * Used memset wherever possible > > * Emit more clear log - unsupported multi-msg i2c transaction > > * Removed mcp2221 entry from hid-quirk.c > > * Removed module parameter to set i2c bus speed > > > > MAINTAINERS | 7 + > > drivers/hid/Kconfig | 10 + > > drivers/hid/Makefile | 1 + > > drivers/hid/hid-ids.h | 1 + > > drivers/hid/hid-mcp2221.c | 742 ++++++++++++++++++++++++++++++++++++++++++++++ > > 5 files changed, 761 insertions(+) > > create mode 100644 drivers/hid/hid-mcp2221.c > > > > diff --git a/MAINTAINERS b/MAINTAINERS > > index 141b8d3..bfcdd55 100644 > > --- a/MAINTAINERS > > +++ b/MAINTAINERS > > @@ -10160,6 +10160,13 @@ F: drivers/net/can/m_can/m_can.c > > F: drivers/net/can/m_can/m_can.h > > F: drivers/net/can/m_can/m_can_platform.c > > > > +MCP2221A MICROCHIP USB-HID TO I2C BRIDGE DRIVER > > +M: Rishi Gupta <gupt21@gmail.com> > > +L: linux-i2c@vger.kernel.org > > +L: linux-input@vger.kernel.org > > +S: Maintained > > +F: drivers/hid/hid-mcp2221.c > > + > > MCP4018 AND MCP4531 MICROCHIP DIGITAL POTENTIOMETER DRIVERS > > M: Peter Rosin <peda@axentia.se> > > L: linux-iio@vger.kernel.org > > diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig > > index 494a39e..5db6e6a 100644 > > --- a/drivers/hid/Kconfig > > +++ b/drivers/hid/Kconfig > > @@ -1145,6 +1145,16 @@ config HID_ALPS > > Say Y here if you have a Alps touchpads over i2c-hid or usbhid > > and want support for its special functionalities. > > > > +config HID_MCP2221 > > + tristate "Microchip MCP2221 HID USB-to-I2C/SMbus host support" > > + depends on USB_HID && I2C > > + ---help--- > > + Provides I2C and SMBUS host adapter functionality over USB-HID > > + through MCP2221 device. > > + > > + To compile this driver as a module, choose M here: the module > > + will be called hid-mcp2221.ko. > > + > > endmenu > > > > endif # HID > > diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile > > index bfefa36..21052a7 100644 > > --- a/drivers/hid/Makefile > > +++ b/drivers/hid/Makefile > > @@ -70,6 +70,7 @@ obj-$(CONFIG_HID_LOGITECH_HIDPP) += hid-logitech-hidpp.o > > obj-$(CONFIG_HID_MACALLY) += hid-macally.o > > obj-$(CONFIG_HID_MAGICMOUSE) += hid-magicmouse.o > > obj-$(CONFIG_HID_MALTRON) += hid-maltron.o > > +obj-$(CONFIG_HID_MCP2221) += hid-mcp2221.o > > obj-$(CONFIG_HID_MAYFLASH) += hid-mf.o > > obj-$(CONFIG_HID_MICROSOFT) += hid-microsoft.o > > obj-$(CONFIG_HID_MONTEREY) += hid-monterey.o > > diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h > > index 3a400ce..53236ac 100644 > > --- a/drivers/hid/hid-ids.h > > +++ b/drivers/hid/hid-ids.h > > @@ -819,6 +819,7 @@ > > #define USB_DEVICE_ID_PICK16F1454 0x0042 > > #define USB_DEVICE_ID_PICK16F1454_V2 0xf2f7 > > #define USB_DEVICE_ID_LUXAFOR 0xf372 > > +#define USB_DEVICE_ID_MCP2221 0x00dd > > > > #define USB_VENDOR_ID_MICROSOFT 0x045e > > #define USB_DEVICE_ID_SIDEWINDER_GV 0x003b > > diff --git a/drivers/hid/hid-mcp2221.c b/drivers/hid/hid-mcp2221.c > > new file mode 100644 > > index 0000000..d958475 > > --- /dev/null > > +++ b/drivers/hid/hid-mcp2221.c > > @@ -0,0 +1,742 @@ > > +// SPDX-License-Identifier: GPL-2.0-only > > +/* > > + * MCP2221A - Microchip USB to I2C Host Protocol Bridge > > + * > > + * Copyright (c) 2020, Rishi Gupta <gupt21@gmail.com> > > + * > > + * Datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/20005565B.pdf > > + */ > > + > > +#include <linux/module.h> > > +#include <linux/err.h> > > +#include <linux/mutex.h> > > +#include <linux/completion.h> > > +#include <linux/delay.h> > > +#include <linux/hid.h> > > +#include <linux/hidraw.h> > > +#include <linux/i2c.h> > > +#include "hid-ids.h" > > + > > +/* Commands codes in a raw output report */ > > +enum { > > + MCP2221_I2C_WR_DATA = 0x90, > > + MCP2221_I2C_WR_NO_STOP = 0x94, > > + MCP2221_I2C_RD_DATA = 0x91, > > + MCP2221_I2C_RD_RPT_START = 0x93, > > + MCP2221_I2C_GET_DATA = 0x40, > > + MCP2221_I2C_PARAM_OR_STATUS = 0x10, > > + MCP2221_I2C_SET_SPEED = 0x20, > > + MCP2221_I2C_CANCEL = 0x10, > > +}; > > + > > +/* Response codes in a raw input report */ > > +enum { > > + MCP2221_SUCCESS = 0x00, > > + MCP2221_I2C_ENG_BUSY = 0x01, > > + MCP2221_I2C_START_TOUT = 0x12, > > + MCP2221_I2C_STOP_TOUT = 0x62, > > + MCP2221_I2C_WRADDRL_TOUT = 0x23, > > + MCP2221_I2C_WRDATA_TOUT = 0x44, > > + MCP2221_I2C_WRADDRL_NACK = 0x25, > > + MCP2221_I2C_MASK_ADDR_NACK = 0x40, > > + MCP2221_I2C_WRADDRL_SEND = 0x21, > > + MCP2221_I2C_ADDR_NACK = 0x25, > > + MCP2221_I2C_READ_COMPL = 0x55, > > +}; > > + > > +/* > > + * There is no way to distinguish responses. Therefore next command > > + * is sent only after response to previous has been received. Mutex > > + * lock is used for this purpose mainly. > > + */ > > +struct mcp2221 { > > + struct hid_device *hdev; > > + struct i2c_adapter adapter; > > + struct mutex lock; > > + struct completion wait_in_report; > > + u8 *rxbuf; > > + u8 txbuf[64]; > > + int rxbuf_idx; > > + int status; > > + u8 cur_i2c_clk_div; > > +}; > > + > > +/* > > + * Default i2c bus clock frequency 400 kHz. Modify this if you > > + * want to set some other frequency (min 50 kHz - max 400 kHz). > > + */ > > +static uint i2c_clk_freq = 400; > > + > > +/* Synchronously send output report to the device */ > > +static int mcp_send_report(struct mcp2221 *mcp, > > + u8 *out_report, size_t len) > > +{ > > + u8 *buf; > > + int ret; > > + > > + buf = kmemdup(out_report, len, GFP_KERNEL); > > + if (!buf) > > + return -ENOMEM; > > + > > + /* mcp2221 uses interrupt endpoint for out reports */ > > + ret = hid_hw_output_report(mcp->hdev, buf, len); > > + kfree(buf); > > + > > + if (ret < 0) > > + return ret; > > + return 0; > > +} > > + > > +/* > > + * Send o/p report to the device and wait for i/p report to be > > + * received from the device. If the device does not respond, > > + * we timeout. > > + */ > > +static int mcp_send_data_req_status(struct mcp2221 *mcp, > > + u8 *out_report, int len) > > +{ > > + int ret; > > + unsigned long t; > > + > > + reinit_completion(&mcp->wait_in_report); > > + > > + ret = mcp_send_report(mcp, out_report, len); > > + if (ret) > > + return ret; > > + > > + t = wait_for_completion_timeout(&mcp->wait_in_report, > > + msecs_to_jiffies(4000)); > > + if (!t) > > + return -ETIMEDOUT; > > + > > + return mcp->status; > > +} > > + > > +/* Check pass/fail for actual communication with i2c slave */ > > +static int mcp_chk_last_cmd_status(struct mcp2221 *mcp) > > +{ > > + memset(mcp->txbuf, 0, 8); > > + mcp->txbuf[0] = MCP2221_I2C_PARAM_OR_STATUS; > > + > > + return mcp_send_data_req_status(mcp, mcp->txbuf, 8); > > +} > > + > > +/* Cancels last command releasing i2c bus just in case occupied */ > > +static int mcp_cancel_last_cmd(struct mcp2221 *mcp) > > +{ > > + memset(mcp->txbuf, 0, 8); > > + mcp->txbuf[0] = MCP2221_I2C_PARAM_OR_STATUS; > > + mcp->txbuf[2] = MCP2221_I2C_CANCEL; > > + > > + return mcp_send_data_req_status(mcp, mcp->txbuf, 8); > > +} > > + > > +static int mcp_set_i2c_speed(struct mcp2221 *mcp) > > +{ > > + int ret; > > + > > + memset(mcp->txbuf, 0, 8); > > + mcp->txbuf[0] = MCP2221_I2C_PARAM_OR_STATUS; > > + mcp->txbuf[3] = MCP2221_I2C_SET_SPEED; > > + mcp->txbuf[4] = mcp->cur_i2c_clk_div; > > + > > + ret = mcp_send_data_req_status(mcp, mcp->txbuf, 8); > > + if (ret) { > > + /* Small delay is needed here */ > > + usleep_range(980, 1000); > > + mcp_cancel_last_cmd(mcp); > > + } > > + > > + return 0; > > +} > > + > > +/* > > + * An output report can contain minimum 1 and maximum 60 user data > > + * bytes. If the number of data bytes is more then 60, we send it > > + * in chunks of 60 bytes. Last chunk may contain exactly 60 or less > > + * bytes. Total number of bytes is informed in very first report to > > + * mcp2221, from that point onwards it first collect all the data > > + * from host and then send to i2c slave device. > > + */ > > +static int mcp_i2c_write(struct mcp2221 *mcp, > > + struct i2c_msg *msg, int type, u8 last_status) > > +{ > > + int ret, len, idx, sent; > > + > > + idx = 0; > > + sent = 0; > > + if (msg->len < 60) > > + len = msg->len; > > + else > > + len = 60; > > + > > + do { > > + mcp->txbuf[0] = type; > > + mcp->txbuf[1] = msg->len & 0xff; > > + mcp->txbuf[2] = msg->len >> 8; > > + mcp->txbuf[3] = (u8)(msg->addr << 1); > > + > > + memcpy(&mcp->txbuf[4], &msg->buf[idx], len); > > + > > + ret = mcp_send_data_req_status(mcp, mcp->txbuf, len + 4); > > + if (ret) > > + return ret; > > + > > + usleep_range(980, 1000); > > + > > + if (last_status) { > > + ret = mcp_chk_last_cmd_status(mcp); > > + if (ret) > > + return ret; > > + } > > + > > + sent = sent + len; > > + if (sent >= msg->len) > > + break; > > + > > + idx = idx + len; > > + if ((msg->len - sent) < 60) > > + len = msg->len - sent; > > + else > > + len = 60; > > + > > + /* > > + * Testing shows delay is needed between successive writes > > + * otherwise next write fails on first-try from i2c core. > > + * This value is obtained through automated stress testing. > > + */ > > + usleep_range(980, 1000); > > + } while (len > 0); > > + > > + return ret; > > +} > > + > > +/* > > + * Device reads all data (0 - 65535 bytes) from i2c slave device and > > + * stores it in device itself. This data is read back from device to > > + * host in multiples of 60 bytes using input reports. > > + */ > > +static int mcp_i2c_smbus_read(struct mcp2221 *mcp, > > + struct i2c_msg *msg, int type, u16 smbus_addr, > > + u8 smbus_len, u8 *smbus_buf) > > +{ > > + int ret; > > + u16 total_len; > > + > > + mcp->txbuf[0] = type; > > + if (msg) { > > + mcp->txbuf[1] = msg->len & 0xff; > > + mcp->txbuf[2] = msg->len >> 8; > > + mcp->txbuf[3] = (u8)(msg->addr << 1); > > + total_len = msg->len; > > + mcp->rxbuf = msg->buf; > > + } else { > > + mcp->txbuf[1] = smbus_len; > > + mcp->txbuf[2] = 0; > > + mcp->txbuf[3] = (u8)(smbus_addr << 1); > > + total_len = smbus_len; > > + mcp->rxbuf = smbus_buf; > > + } > > + > > + ret = mcp_send_data_req_status(mcp, mcp->txbuf, 4); > > + if (ret) > > + return ret; > > + > > + mcp->rxbuf_idx = 0; > > + > > + do { > > + memset(mcp->txbuf, 0, 4); > > + mcp->txbuf[0] = MCP2221_I2C_GET_DATA; > > + > > + ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1); > > + if (ret) > > + return ret; > > + > > + ret = mcp_chk_last_cmd_status(mcp); > > + if (ret) > > + return ret; > > + > > + usleep_range(980, 1000); > > + } while (mcp->rxbuf_idx < total_len); > > + > > + return ret; > > +} > > + > > +static int mcp_i2c_xfer(struct i2c_adapter *adapter, > > + struct i2c_msg msgs[], int num) > > +{ > > + int ret; > > + struct mcp2221 *mcp = i2c_get_adapdata(adapter); > > + > > + hid_hw_power(mcp->hdev, PM_HINT_FULLON); > > + > > + mutex_lock(&mcp->lock); > > + > > + /* Setting speed before every transaction is required for mcp2221 */ > > + ret = mcp_set_i2c_speed(mcp); > > + if (ret) > > + goto exit; > > + > > + if (num == 1) { > > + if (msgs->flags & I2C_M_RD) { > > + ret = mcp_i2c_smbus_read(mcp, msgs, MCP2221_I2C_RD_DATA, > > + 0, 0, NULL); > > + } else { > > + ret = mcp_i2c_write(mcp, msgs, MCP2221_I2C_WR_DATA, 1); > > + } > > + if (ret) > > + goto exit; > > + ret = num; > > + } else if (num == 2) { > > + /* Ex transaction; send reg address and read its contents */ > > + if (msgs[0].addr == msgs[1].addr && > > + !(msgs[0].flags & I2C_M_RD) && > > + (msgs[1].flags & I2C_M_RD)) { > > + > > + ret = mcp_i2c_write(mcp, &msgs[0], > > + MCP2221_I2C_WR_NO_STOP, 0); > > + if (ret) > > + goto exit; > > + > > + ret = mcp_i2c_smbus_read(mcp, &msgs[1], > > + MCP2221_I2C_RD_RPT_START, > > + 0, 0, NULL); > > + if (ret) > > + goto exit; > > + ret = num; > > + } else { > > + dev_err(&adapter->dev, > > + "unsupported multi-msg i2c transaction\n"); > > + ret = -EOPNOTSUPP; > > + } > > + } else { > > + dev_err(&adapter->dev, > > + "unsupported multi-msg i2c transaction\n"); > > + ret = -EOPNOTSUPP; > > + } > > + > > +exit: > > + hid_hw_power(mcp->hdev, PM_HINT_NORMAL); > > + mutex_unlock(&mcp->lock); > > + return ret; > > +} > > + > > +static int mcp_smbus_write(struct mcp2221 *mcp, u16 addr, > > + u8 command, u8 *buf, u8 len, int type, > > + u8 last_status) > > +{ > > + int data_len, ret; > > + > > + mcp->txbuf[0] = type; > > + mcp->txbuf[1] = len + 1; /* 1 is due to command byte itself */ > > + mcp->txbuf[2] = 0; > > + mcp->txbuf[3] = (u8)(addr << 1); > > + mcp->txbuf[4] = command; > > + > > + switch (len) { > > + case 0: > > + data_len = 5; > > + break; > > + case 1: > > + mcp->txbuf[5] = buf[0]; > > + data_len = 6; > > + break; > > + case 2: > > + mcp->txbuf[5] = buf[0]; > > + mcp->txbuf[6] = buf[1]; > > + data_len = 7; > > + break; > > + default: > > + memcpy(&mcp->txbuf[5], buf, len); > > + data_len = len + 5; > > + } > > + > > + ret = mcp_send_data_req_status(mcp, mcp->txbuf, data_len); > > + if (ret) > > + return ret; > > + > > + if (last_status) { > > + usleep_range(980, 1000); > > + > > + ret = mcp_chk_last_cmd_status(mcp); > > + if (ret) > > + return ret; > > + } > > + > > + return ret; > > +} > > + > > +static int mcp_smbus_xfer(struct i2c_adapter *adapter, u16 addr, > > + unsigned short flags, char read_write, > > + u8 command, int size, > > + union i2c_smbus_data *data) > > +{ > > + int ret; > > + struct mcp2221 *mcp = i2c_get_adapdata(adapter); > > + > > + hid_hw_power(mcp->hdev, PM_HINT_FULLON); > > + > > + mutex_lock(&mcp->lock); > > + > > + ret = mcp_set_i2c_speed(mcp); > > + if (ret) > > + goto exit; > > + > > + switch (size) { > > + > > + case I2C_SMBUS_QUICK: > > + if (read_write == I2C_SMBUS_READ) > > + ret = mcp_i2c_smbus_read(mcp, NULL, MCP2221_I2C_RD_DATA, > > + addr, 0, &data->byte); > > + else > > + ret = mcp_smbus_write(mcp, addr, command, NULL, > > + 0, MCP2221_I2C_WR_DATA, 1); > > + break; > > + case I2C_SMBUS_BYTE: > > + if (read_write == I2C_SMBUS_READ) > > + ret = mcp_i2c_smbus_read(mcp, NULL, MCP2221_I2C_RD_DATA, > > + addr, 1, &data->byte); > > + else > > + ret = mcp_smbus_write(mcp, addr, command, NULL, > > + 0, MCP2221_I2C_WR_DATA, 1); > > + break; > > + case I2C_SMBUS_BYTE_DATA: > > + if (read_write == I2C_SMBUS_READ) { > > + ret = mcp_smbus_write(mcp, addr, command, NULL, > > + 0, MCP2221_I2C_WR_NO_STOP, 0); > > + if (ret) > > + goto exit; > > + > > + ret = mcp_i2c_smbus_read(mcp, NULL, > > + MCP2221_I2C_RD_RPT_START, > > + addr, 1, &data->byte); > > + } else { > > + ret = mcp_smbus_write(mcp, addr, command, &data->byte, > > + 1, MCP2221_I2C_WR_DATA, 1); > > + } > > + break; > > + case I2C_SMBUS_WORD_DATA: > > + if (read_write == I2C_SMBUS_READ) { > > + ret = mcp_smbus_write(mcp, addr, command, NULL, > > + 0, MCP2221_I2C_WR_NO_STOP, 0); > > + if (ret) > > + goto exit; > > + > > + ret = mcp_i2c_smbus_read(mcp, NULL, > > + MCP2221_I2C_RD_RPT_START, > > + addr, 2, (u8 *)&data->word); > > + } else { > > + ret = mcp_smbus_write(mcp, addr, command, > > + (u8 *)&data->word, 2, > > + MCP2221_I2C_WR_DATA, 1); > > + } > > + break; > > + case I2C_SMBUS_BLOCK_DATA: > > + if (read_write == I2C_SMBUS_READ) { > > + ret = mcp_smbus_write(mcp, addr, command, NULL, > > + 0, MCP2221_I2C_WR_NO_STOP, 1); > > + if (ret) > > + goto exit; > > + > > + mcp->rxbuf_idx = 0; > > + mcp->rxbuf = data->block; > > + mcp->txbuf[0] = MCP2221_I2C_GET_DATA; > > + ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1); > > + if (ret) > > + goto exit; > > + } else { > > + if (!data->block[0]) { > > + ret = -EINVAL; > > + goto exit; > > + } > > + ret = mcp_smbus_write(mcp, addr, command, data->block, > > + data->block[0] + 1, > > + MCP2221_I2C_WR_DATA, 1); > > + } > > + break; > > + case I2C_SMBUS_I2C_BLOCK_DATA: > > + if (read_write == I2C_SMBUS_READ) { > > + ret = mcp_smbus_write(mcp, addr, command, NULL, > > + 0, MCP2221_I2C_WR_NO_STOP, 1); > > + if (ret) > > + goto exit; > > + > > + mcp->rxbuf_idx = 0; > > + mcp->rxbuf = data->block; > > + mcp->txbuf[0] = MCP2221_I2C_GET_DATA; > > + ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1); > > + if (ret) > > + goto exit; > > + } else { > > + if (!data->block[0]) { > > + ret = -EINVAL; > > + goto exit; > > + } > > + ret = mcp_smbus_write(mcp, addr, command, > > + &data->block[1], data->block[0], > > + MCP2221_I2C_WR_DATA, 1); > > + } > > + break; > > + case I2C_SMBUS_PROC_CALL: > > + ret = mcp_smbus_write(mcp, addr, command, > > + (u8 *)&data->word, > > + 2, MCP2221_I2C_WR_NO_STOP, 0); > > + if (ret) > > + goto exit; > > + > > + ret = mcp_i2c_smbus_read(mcp, NULL, > > + MCP2221_I2C_RD_RPT_START, > > + addr, 2, (u8 *)&data->word); > > + break; > > + case I2C_SMBUS_BLOCK_PROC_CALL: > > + ret = mcp_smbus_write(mcp, addr, command, data->block, > > + data->block[0] + 1, > > + MCP2221_I2C_WR_NO_STOP, 0); > > + if (ret) > > + goto exit; > > + > > + ret = mcp_i2c_smbus_read(mcp, NULL, > > + MCP2221_I2C_RD_RPT_START, > > + addr, I2C_SMBUS_BLOCK_MAX, > > + data->block); > > + break; > > + default: > > + dev_err(&mcp->adapter.dev, > > + "unsupported smbus transaction size:%d\n", size); > > + ret = -EOPNOTSUPP; > > + } > > + > > +exit: > > + hid_hw_power(mcp->hdev, PM_HINT_NORMAL); > > + mutex_unlock(&mcp->lock); > > + return ret; > > +} > > + > > +static u32 mcp_i2c_func(struct i2c_adapter *adapter) > > +{ > > + return I2C_FUNC_I2C | > > + I2C_FUNC_SMBUS_READ_BLOCK_DATA | > > + I2C_FUNC_SMBUS_BLOCK_PROC_CALL | > > + (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_PEC); > > +} > > + > > +static const struct i2c_algorithm mcp_i2c_algo = { > > + .master_xfer = mcp_i2c_xfer, > > + .smbus_xfer = mcp_smbus_xfer, > > + .functionality = mcp_i2c_func, > > +}; > > + > > +/* Gives current state of i2c engine inside mcp2221 */ > > +static int mcp_get_i2c_eng_state(struct mcp2221 *mcp, > > + u8 *data, u8 idx) > > +{ > > + int ret; > > + > > + switch (data[idx]) { > > + case MCP2221_I2C_WRADDRL_NACK: > > + case MCP2221_I2C_WRADDRL_SEND: > > + ret = -ENXIO; > > + break; > > + case MCP2221_I2C_START_TOUT: > > + case MCP2221_I2C_STOP_TOUT: > > + case MCP2221_I2C_WRADDRL_TOUT: > > + case MCP2221_I2C_WRDATA_TOUT: > > + ret = -ETIMEDOUT; > > + break; > > + case MCP2221_I2C_ENG_BUSY: > > + ret = -EAGAIN; > > + break; > > + case MCP2221_SUCCESS: > > + ret = 0x00; > > + break; > > + default: > > + ret = -EIO; > > + } > > + > > + return ret; > > +} > > + > > +/* > > + * MCP2221 uses interrupt endpoint for input reports. This function > > + * is called by HID layer when it receives i/p report from mcp2221, > > + * which is actually a response to the previously sent command. > > + * > > + * MCP2221A firmware specific return codes are parsed and 0 or > > + * appropriate negative error code is returned. Delayed response > > + * results in timeout error and stray reponses results in -EIO. > > + */ > > +static int mcp2221_raw_event(struct hid_device *hdev, > > + struct hid_report *report, u8 *data, int size) > > +{ > > + u8 *buf; > > + struct mcp2221 *mcp = hid_get_drvdata(hdev); > > + > > + switch (data[0]) { > > + > > + case MCP2221_I2C_WR_DATA: > > + case MCP2221_I2C_WR_NO_STOP: > > + case MCP2221_I2C_RD_DATA: > > + case MCP2221_I2C_RD_RPT_START: > > + switch (data[1]) { > > + case MCP2221_SUCCESS: > > + mcp->status = 0; > > + break; > > + default: > > + mcp->status = mcp_get_i2c_eng_state(mcp, data, 2); > > + } > > + complete(&mcp->wait_in_report); > > + break; > > + > > + case MCP2221_I2C_PARAM_OR_STATUS: > > + switch (data[1]) { > > + case MCP2221_SUCCESS: > > + if ((mcp->txbuf[3] == MCP2221_I2C_SET_SPEED) && > > + (data[3] != MCP2221_I2C_SET_SPEED)) { > > + mcp->status = -EAGAIN; > > + break; > > + } > > + if (data[20] & MCP2221_I2C_MASK_ADDR_NACK) { > > + mcp->status = -ENXIO; > > + break; > > + } > > + mcp->status = mcp_get_i2c_eng_state(mcp, data, 8); > > + break; > > + default: > > + mcp->status = -EIO; > > + } > > + complete(&mcp->wait_in_report); > > + break; > > + > > + case MCP2221_I2C_GET_DATA: > > + switch (data[1]) { > > + case MCP2221_SUCCESS: > > + if (data[2] == MCP2221_I2C_ADDR_NACK) { > > + mcp->status = -ENXIO; > > + break; > > + } > > + if (!mcp_get_i2c_eng_state(mcp, data, 2) > > + && (data[3] == 0)) { > > + mcp->status = 0; > > + break; > > + } > > + if (data[3] == 127) { > > + mcp->status = -EIO; > > + break; > > + } > > + if (data[2] == MCP2221_I2C_READ_COMPL) { > > + buf = mcp->rxbuf; > > + memcpy(&buf[mcp->rxbuf_idx], &data[4], data[3]); > > + mcp->rxbuf_idx = mcp->rxbuf_idx + data[3]; > > + mcp->status = 0; > > + break; > > + } > > + mcp->status = -EIO; > > + break; > > + default: > > + mcp->status = -EIO; > > + } > > + complete(&mcp->wait_in_report); > > + break; > > + > > + default: > > + mcp->status = -EIO; > > + complete(&mcp->wait_in_report); > > + } > > + > > + return 1; > > +} > > + > > +static int mcp2221_probe(struct hid_device *hdev, > > + const struct hid_device_id *id) > > +{ > > + int ret; > > + struct mcp2221 *mcp; > > + > > + mcp = devm_kzalloc(&hdev->dev, sizeof(*mcp), GFP_KERNEL); > > + if (!mcp) > > + return -ENOMEM; > > + > > + ret = hid_parse(hdev); > > + if (ret) { > > + hid_err(hdev, "can't parse reports\n"); > > + return ret; > > + } > > + > > + ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW); > > + if (ret) { > > + hid_err(hdev, "can't start hardware\n"); > > + return ret; > > + } > > + > > + ret = hid_hw_open(hdev); > > + if (ret) { > > + hid_err(hdev, "can't open device\n"); > > + goto err_hstop; > > + } > > + > > + mutex_init(&mcp->lock); > > + init_completion(&mcp->wait_in_report); > > + hid_set_drvdata(hdev, mcp); > > + mcp->hdev = hdev; > > + > > + /* Set I2C bus clock diviser */ > > + if (i2c_clk_freq > 400) > > + i2c_clk_freq = 400; > > + if (i2c_clk_freq < 50) > > + i2c_clk_freq = 50; > > + mcp->cur_i2c_clk_div = (12000000 / (i2c_clk_freq * 1000)) - 3; > > + > > + mcp->adapter.owner = THIS_MODULE; > > + mcp->adapter.class = I2C_CLASS_HWMON; > > + mcp->adapter.algo = &mcp_i2c_algo; > > + mcp->adapter.retries = 1; > > + mcp->adapter.dev.parent = &hdev->dev; > > + snprintf(mcp->adapter.name, sizeof(mcp->adapter.name), > > + "MCP2221 usb-i2c bridge on hidraw%d", > > + ((struct hidraw *)hdev->hidraw)->minor); > > + > > + ret = i2c_add_adapter(&mcp->adapter); > > + if (ret) { > > + hid_err(hdev, "can't add usb-i2c adapter: %d\n", ret); > > + goto err_i2c; > > + } > > + i2c_set_adapdata(&mcp->adapter, mcp); > > + > > + return 0; > > + > > +err_i2c: > > + hid_hw_close(mcp->hdev); > > +err_hstop: > > + hid_hw_stop(mcp->hdev); > > + return ret; > > +} > > + > > +static void mcp2221_remove(struct hid_device *hdev) > > +{ > > + struct mcp2221 *mcp = hid_get_drvdata(hdev); > > + > > + i2c_del_adapter(&mcp->adapter); > > + hid_hw_close(mcp->hdev); > > + hid_hw_stop(mcp->hdev); > > +} > > + > > +static const struct hid_device_id mcp2221_devices[] = { > > + { HID_USB_DEVICE(USB_VENDOR_ID_MICROCHIP, USB_DEVICE_ID_MCP2221) }, > > + { } > > +}; > > +MODULE_DEVICE_TABLE(hid, mcp2221_devices); > > + > > +static struct hid_driver mcp2221_driver = { > > + .name = "mcp2221", > > + .id_table = mcp2221_devices, > > + .probe = mcp2221_probe, > > + .remove = mcp2221_remove, > > + .raw_event = mcp2221_raw_event, > > +}; > > + > > +/* Register with HID core */ > > +module_hid_driver(mcp2221_driver); > > + > > +MODULE_AUTHOR("Rishi Gupta <gupt21@gmail.com>"); > > +MODULE_DESCRIPTION("MCP2221 Microchip HID USB to I2C master bridge"); > > +MODULE_LICENSE("GPL v2"); > > -- > > 2.7.4 > >
On Tue, 28 Jan 2020, Rishi Gupta wrote: > MCP2221 is a USB HID to I2C/SMbus host bridge device. This > commit implements i2c and smbus host adapter support. 7-bit > address and i2c multi-message transaction is also supported. Applied; sorry this took me a bit longer to review.
I am really grateful to you and all other maintainers. You really do a lot work; code review is a manual and time consuming task. Regards, Rishi On Tue, Mar 10, 2020 at 5:12 PM Jiri Kosina <jikos@kernel.org> wrote: > > On Tue, 28 Jan 2020, Rishi Gupta wrote: > > > MCP2221 is a USB HID to I2C/SMbus host bridge device. This > > commit implements i2c and smbus host adapter support. 7-bit > > address and i2c multi-message transaction is also supported. > > Applied; sorry this took me a bit longer to review. > > -- > Jiri Kosina > SUSE Labs >
> + if (num == 1) { > + if (msgs->flags & I2C_M_RD) { > + ret = mcp_i2c_smbus_read(mcp, msgs, MCP2221_I2C_RD_DATA, > + 0, 0, NULL); > + } else { > + ret = mcp_i2c_write(mcp, msgs, MCP2221_I2C_WR_DATA, 1); > + } > + if (ret) > + goto exit; > + ret = num; > + } else if (num == 2) { > + /* Ex transaction; send reg address and read its contents */ > + if (msgs[0].addr == msgs[1].addr && > + !(msgs[0].flags & I2C_M_RD) && > + (msgs[1].flags & I2C_M_RD)) { > + > + ret = mcp_i2c_write(mcp, &msgs[0], > + MCP2221_I2C_WR_NO_STOP, 0); > + if (ret) > + goto exit; > + > + ret = mcp_i2c_smbus_read(mcp, &msgs[1], > + MCP2221_I2C_RD_RPT_START, > + 0, 0, NULL); > + if (ret) > + goto exit; > + ret = num; > + } else { > + dev_err(&adapter->dev, > + "unsupported multi-msg i2c transaction\n"); > + ret = -EOPNOTSUPP; > + } > + } else { > + dev_err(&adapter->dev, > + "unsupported multi-msg i2c transaction\n"); > + ret = -EOPNOTSUPP; > + } Have a look at struct i2c_adapter_quirks and especially the flags to let the I2C core do the sanity checks from here.
I will send two more patches in sometime.
Patch 1: Define i2c_adapter_quirks to let i2c core check msg's order,
type and length
As of now this driver itself is doing this sanity.
Patch 2: Add support for GPIO functionality
On Tue, Mar 10, 2020 at 5:59 PM Wolfram Sang <wsa@the-dreams.de> wrote:
>
>
> > + if (num == 1) {
> > + if (msgs->flags & I2C_M_RD) {
> > + ret = mcp_i2c_smbus_read(mcp, msgs, MCP2221_I2C_RD_DATA,
> > + 0, 0, NULL);
> > + } else {
> > + ret = mcp_i2c_write(mcp, msgs, MCP2221_I2C_WR_DATA, 1);
> > + }
> > + if (ret)
> > + goto exit;
> > + ret = num;
> > + } else if (num == 2) {
> > + /* Ex transaction; send reg address and read its contents */
> > + if (msgs[0].addr == msgs[1].addr &&
> > + !(msgs[0].flags & I2C_M_RD) &&
> > + (msgs[1].flags & I2C_M_RD)) {
> > +
> > + ret = mcp_i2c_write(mcp, &msgs[0],
> > + MCP2221_I2C_WR_NO_STOP, 0);
> > + if (ret)
> > + goto exit;
> > +
> > + ret = mcp_i2c_smbus_read(mcp, &msgs[1],
> > + MCP2221_I2C_RD_RPT_START,
> > + 0, 0, NULL);
> > + if (ret)
> > + goto exit;
> > + ret = num;
> > + } else {
> > + dev_err(&adapter->dev,
> > + "unsupported multi-msg i2c transaction\n");
> > + ret = -EOPNOTSUPP;
> > + }
> > + } else {
> > + dev_err(&adapter->dev,
> > + "unsupported multi-msg i2c transaction\n");
> > + ret = -EOPNOTSUPP;
> > + }
>
> Have a look at struct i2c_adapter_quirks and especially the flags to let
> the I2C core do the sanity checks from here.
>
diff --git a/MAINTAINERS b/MAINTAINERS index 141b8d3..bfcdd55 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -10160,6 +10160,13 @@ F: drivers/net/can/m_can/m_can.c F: drivers/net/can/m_can/m_can.h F: drivers/net/can/m_can/m_can_platform.c +MCP2221A MICROCHIP USB-HID TO I2C BRIDGE DRIVER +M: Rishi Gupta <gupt21@gmail.com> +L: linux-i2c@vger.kernel.org +L: linux-input@vger.kernel.org +S: Maintained +F: drivers/hid/hid-mcp2221.c + MCP4018 AND MCP4531 MICROCHIP DIGITAL POTENTIOMETER DRIVERS M: Peter Rosin <peda@axentia.se> L: linux-iio@vger.kernel.org diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig index 494a39e..5db6e6a 100644 --- a/drivers/hid/Kconfig +++ b/drivers/hid/Kconfig @@ -1145,6 +1145,16 @@ config HID_ALPS Say Y here if you have a Alps touchpads over i2c-hid or usbhid and want support for its special functionalities. +config HID_MCP2221 + tristate "Microchip MCP2221 HID USB-to-I2C/SMbus host support" + depends on USB_HID && I2C + ---help--- + Provides I2C and SMBUS host adapter functionality over USB-HID + through MCP2221 device. + + To compile this driver as a module, choose M here: the module + will be called hid-mcp2221.ko. + endmenu endif # HID diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile index bfefa36..21052a7 100644 --- a/drivers/hid/Makefile +++ b/drivers/hid/Makefile @@ -70,6 +70,7 @@ obj-$(CONFIG_HID_LOGITECH_HIDPP) += hid-logitech-hidpp.o obj-$(CONFIG_HID_MACALLY) += hid-macally.o obj-$(CONFIG_HID_MAGICMOUSE) += hid-magicmouse.o obj-$(CONFIG_HID_MALTRON) += hid-maltron.o +obj-$(CONFIG_HID_MCP2221) += hid-mcp2221.o obj-$(CONFIG_HID_MAYFLASH) += hid-mf.o obj-$(CONFIG_HID_MICROSOFT) += hid-microsoft.o obj-$(CONFIG_HID_MONTEREY) += hid-monterey.o diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h index 3a400ce..53236ac 100644 --- a/drivers/hid/hid-ids.h +++ b/drivers/hid/hid-ids.h @@ -819,6 +819,7 @@ #define USB_DEVICE_ID_PICK16F1454 0x0042 #define USB_DEVICE_ID_PICK16F1454_V2 0xf2f7 #define USB_DEVICE_ID_LUXAFOR 0xf372 +#define USB_DEVICE_ID_MCP2221 0x00dd #define USB_VENDOR_ID_MICROSOFT 0x045e #define USB_DEVICE_ID_SIDEWINDER_GV 0x003b diff --git a/drivers/hid/hid-mcp2221.c b/drivers/hid/hid-mcp2221.c new file mode 100644 index 0000000..d958475 --- /dev/null +++ b/drivers/hid/hid-mcp2221.c @@ -0,0 +1,742 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * MCP2221A - Microchip USB to I2C Host Protocol Bridge + * + * Copyright (c) 2020, Rishi Gupta <gupt21@gmail.com> + * + * Datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/20005565B.pdf + */ + +#include <linux/module.h> +#include <linux/err.h> +#include <linux/mutex.h> +#include <linux/completion.h> +#include <linux/delay.h> +#include <linux/hid.h> +#include <linux/hidraw.h> +#include <linux/i2c.h> +#include "hid-ids.h" + +/* Commands codes in a raw output report */ +enum { + MCP2221_I2C_WR_DATA = 0x90, + MCP2221_I2C_WR_NO_STOP = 0x94, + MCP2221_I2C_RD_DATA = 0x91, + MCP2221_I2C_RD_RPT_START = 0x93, + MCP2221_I2C_GET_DATA = 0x40, + MCP2221_I2C_PARAM_OR_STATUS = 0x10, + MCP2221_I2C_SET_SPEED = 0x20, + MCP2221_I2C_CANCEL = 0x10, +}; + +/* Response codes in a raw input report */ +enum { + MCP2221_SUCCESS = 0x00, + MCP2221_I2C_ENG_BUSY = 0x01, + MCP2221_I2C_START_TOUT = 0x12, + MCP2221_I2C_STOP_TOUT = 0x62, + MCP2221_I2C_WRADDRL_TOUT = 0x23, + MCP2221_I2C_WRDATA_TOUT = 0x44, + MCP2221_I2C_WRADDRL_NACK = 0x25, + MCP2221_I2C_MASK_ADDR_NACK = 0x40, + MCP2221_I2C_WRADDRL_SEND = 0x21, + MCP2221_I2C_ADDR_NACK = 0x25, + MCP2221_I2C_READ_COMPL = 0x55, +}; + +/* + * There is no way to distinguish responses. Therefore next command + * is sent only after response to previous has been received. Mutex + * lock is used for this purpose mainly. + */ +struct mcp2221 { + struct hid_device *hdev; + struct i2c_adapter adapter; + struct mutex lock; + struct completion wait_in_report; + u8 *rxbuf; + u8 txbuf[64]; + int rxbuf_idx; + int status; + u8 cur_i2c_clk_div; +}; + +/* + * Default i2c bus clock frequency 400 kHz. Modify this if you + * want to set some other frequency (min 50 kHz - max 400 kHz). + */ +static uint i2c_clk_freq = 400; + +/* Synchronously send output report to the device */ +static int mcp_send_report(struct mcp2221 *mcp, + u8 *out_report, size_t len) +{ + u8 *buf; + int ret; + + buf = kmemdup(out_report, len, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + /* mcp2221 uses interrupt endpoint for out reports */ + ret = hid_hw_output_report(mcp->hdev, buf, len); + kfree(buf); + + if (ret < 0) + return ret; + return 0; +} + +/* + * Send o/p report to the device and wait for i/p report to be + * received from the device. If the device does not respond, + * we timeout. + */ +static int mcp_send_data_req_status(struct mcp2221 *mcp, + u8 *out_report, int len) +{ + int ret; + unsigned long t; + + reinit_completion(&mcp->wait_in_report); + + ret = mcp_send_report(mcp, out_report, len); + if (ret) + return ret; + + t = wait_for_completion_timeout(&mcp->wait_in_report, + msecs_to_jiffies(4000)); + if (!t) + return -ETIMEDOUT; + + return mcp->status; +} + +/* Check pass/fail for actual communication with i2c slave */ +static int mcp_chk_last_cmd_status(struct mcp2221 *mcp) +{ + memset(mcp->txbuf, 0, 8); + mcp->txbuf[0] = MCP2221_I2C_PARAM_OR_STATUS; + + return mcp_send_data_req_status(mcp, mcp->txbuf, 8); +} + +/* Cancels last command releasing i2c bus just in case occupied */ +static int mcp_cancel_last_cmd(struct mcp2221 *mcp) +{ + memset(mcp->txbuf, 0, 8); + mcp->txbuf[0] = MCP2221_I2C_PARAM_OR_STATUS; + mcp->txbuf[2] = MCP2221_I2C_CANCEL; + + return mcp_send_data_req_status(mcp, mcp->txbuf, 8); +} + +static int mcp_set_i2c_speed(struct mcp2221 *mcp) +{ + int ret; + + memset(mcp->txbuf, 0, 8); + mcp->txbuf[0] = MCP2221_I2C_PARAM_OR_STATUS; + mcp->txbuf[3] = MCP2221_I2C_SET_SPEED; + mcp->txbuf[4] = mcp->cur_i2c_clk_div; + + ret = mcp_send_data_req_status(mcp, mcp->txbuf, 8); + if (ret) { + /* Small delay is needed here */ + usleep_range(980, 1000); + mcp_cancel_last_cmd(mcp); + } + + return 0; +} + +/* + * An output report can contain minimum 1 and maximum 60 user data + * bytes. If the number of data bytes is more then 60, we send it + * in chunks of 60 bytes. Last chunk may contain exactly 60 or less + * bytes. Total number of bytes is informed in very first report to + * mcp2221, from that point onwards it first collect all the data + * from host and then send to i2c slave device. + */ +static int mcp_i2c_write(struct mcp2221 *mcp, + struct i2c_msg *msg, int type, u8 last_status) +{ + int ret, len, idx, sent; + + idx = 0; + sent = 0; + if (msg->len < 60) + len = msg->len; + else + len = 60; + + do { + mcp->txbuf[0] = type; + mcp->txbuf[1] = msg->len & 0xff; + mcp->txbuf[2] = msg->len >> 8; + mcp->txbuf[3] = (u8)(msg->addr << 1); + + memcpy(&mcp->txbuf[4], &msg->buf[idx], len); + + ret = mcp_send_data_req_status(mcp, mcp->txbuf, len + 4); + if (ret) + return ret; + + usleep_range(980, 1000); + + if (last_status) { + ret = mcp_chk_last_cmd_status(mcp); + if (ret) + return ret; + } + + sent = sent + len; + if (sent >= msg->len) + break; + + idx = idx + len; + if ((msg->len - sent) < 60) + len = msg->len - sent; + else + len = 60; + + /* + * Testing shows delay is needed between successive writes + * otherwise next write fails on first-try from i2c core. + * This value is obtained through automated stress testing. + */ + usleep_range(980, 1000); + } while (len > 0); + + return ret; +} + +/* + * Device reads all data (0 - 65535 bytes) from i2c slave device and + * stores it in device itself. This data is read back from device to + * host in multiples of 60 bytes using input reports. + */ +static int mcp_i2c_smbus_read(struct mcp2221 *mcp, + struct i2c_msg *msg, int type, u16 smbus_addr, + u8 smbus_len, u8 *smbus_buf) +{ + int ret; + u16 total_len; + + mcp->txbuf[0] = type; + if (msg) { + mcp->txbuf[1] = msg->len & 0xff; + mcp->txbuf[2] = msg->len >> 8; + mcp->txbuf[3] = (u8)(msg->addr << 1); + total_len = msg->len; + mcp->rxbuf = msg->buf; + } else { + mcp->txbuf[1] = smbus_len; + mcp->txbuf[2] = 0; + mcp->txbuf[3] = (u8)(smbus_addr << 1); + total_len = smbus_len; + mcp->rxbuf = smbus_buf; + } + + ret = mcp_send_data_req_status(mcp, mcp->txbuf, 4); + if (ret) + return ret; + + mcp->rxbuf_idx = 0; + + do { + memset(mcp->txbuf, 0, 4); + mcp->txbuf[0] = MCP2221_I2C_GET_DATA; + + ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1); + if (ret) + return ret; + + ret = mcp_chk_last_cmd_status(mcp); + if (ret) + return ret; + + usleep_range(980, 1000); + } while (mcp->rxbuf_idx < total_len); + + return ret; +} + +static int mcp_i2c_xfer(struct i2c_adapter *adapter, + struct i2c_msg msgs[], int num) +{ + int ret; + struct mcp2221 *mcp = i2c_get_adapdata(adapter); + + hid_hw_power(mcp->hdev, PM_HINT_FULLON); + + mutex_lock(&mcp->lock); + + /* Setting speed before every transaction is required for mcp2221 */ + ret = mcp_set_i2c_speed(mcp); + if (ret) + goto exit; + + if (num == 1) { + if (msgs->flags & I2C_M_RD) { + ret = mcp_i2c_smbus_read(mcp, msgs, MCP2221_I2C_RD_DATA, + 0, 0, NULL); + } else { + ret = mcp_i2c_write(mcp, msgs, MCP2221_I2C_WR_DATA, 1); + } + if (ret) + goto exit; + ret = num; + } else if (num == 2) { + /* Ex transaction; send reg address and read its contents */ + if (msgs[0].addr == msgs[1].addr && + !(msgs[0].flags & I2C_M_RD) && + (msgs[1].flags & I2C_M_RD)) { + + ret = mcp_i2c_write(mcp, &msgs[0], + MCP2221_I2C_WR_NO_STOP, 0); + if (ret) + goto exit; + + ret = mcp_i2c_smbus_read(mcp, &msgs[1], + MCP2221_I2C_RD_RPT_START, + 0, 0, NULL); + if (ret) + goto exit; + ret = num; + } else { + dev_err(&adapter->dev, + "unsupported multi-msg i2c transaction\n"); + ret = -EOPNOTSUPP; + } + } else { + dev_err(&adapter->dev, + "unsupported multi-msg i2c transaction\n"); + ret = -EOPNOTSUPP; + } + +exit: + hid_hw_power(mcp->hdev, PM_HINT_NORMAL); + mutex_unlock(&mcp->lock); + return ret; +} + +static int mcp_smbus_write(struct mcp2221 *mcp, u16 addr, + u8 command, u8 *buf, u8 len, int type, + u8 last_status) +{ + int data_len, ret; + + mcp->txbuf[0] = type; + mcp->txbuf[1] = len + 1; /* 1 is due to command byte itself */ + mcp->txbuf[2] = 0; + mcp->txbuf[3] = (u8)(addr << 1); + mcp->txbuf[4] = command; + + switch (len) { + case 0: + data_len = 5; + break; + case 1: + mcp->txbuf[5] = buf[0]; + data_len = 6; + break; + case 2: + mcp->txbuf[5] = buf[0]; + mcp->txbuf[6] = buf[1]; + data_len = 7; + break; + default: + memcpy(&mcp->txbuf[5], buf, len); + data_len = len + 5; + } + + ret = mcp_send_data_req_status(mcp, mcp->txbuf, data_len); + if (ret) + return ret; + + if (last_status) { + usleep_range(980, 1000); + + ret = mcp_chk_last_cmd_status(mcp); + if (ret) + return ret; + } + + return ret; +} + +static int mcp_smbus_xfer(struct i2c_adapter *adapter, u16 addr, + unsigned short flags, char read_write, + u8 command, int size, + union i2c_smbus_data *data) +{ + int ret; + struct mcp2221 *mcp = i2c_get_adapdata(adapter); + + hid_hw_power(mcp->hdev, PM_HINT_FULLON); + + mutex_lock(&mcp->lock); + + ret = mcp_set_i2c_speed(mcp); + if (ret) + goto exit; + + switch (size) { + + case I2C_SMBUS_QUICK: + if (read_write == I2C_SMBUS_READ) + ret = mcp_i2c_smbus_read(mcp, NULL, MCP2221_I2C_RD_DATA, + addr, 0, &data->byte); + else + ret = mcp_smbus_write(mcp, addr, command, NULL, + 0, MCP2221_I2C_WR_DATA, 1); + break; + case I2C_SMBUS_BYTE: + if (read_write == I2C_SMBUS_READ) + ret = mcp_i2c_smbus_read(mcp, NULL, MCP2221_I2C_RD_DATA, + addr, 1, &data->byte); + else + ret = mcp_smbus_write(mcp, addr, command, NULL, + 0, MCP2221_I2C_WR_DATA, 1); + break; + case I2C_SMBUS_BYTE_DATA: + if (read_write == I2C_SMBUS_READ) { + ret = mcp_smbus_write(mcp, addr, command, NULL, + 0, MCP2221_I2C_WR_NO_STOP, 0); + if (ret) + goto exit; + + ret = mcp_i2c_smbus_read(mcp, NULL, + MCP2221_I2C_RD_RPT_START, + addr, 1, &data->byte); + } else { + ret = mcp_smbus_write(mcp, addr, command, &data->byte, + 1, MCP2221_I2C_WR_DATA, 1); + } + break; + case I2C_SMBUS_WORD_DATA: + if (read_write == I2C_SMBUS_READ) { + ret = mcp_smbus_write(mcp, addr, command, NULL, + 0, MCP2221_I2C_WR_NO_STOP, 0); + if (ret) + goto exit; + + ret = mcp_i2c_smbus_read(mcp, NULL, + MCP2221_I2C_RD_RPT_START, + addr, 2, (u8 *)&data->word); + } else { + ret = mcp_smbus_write(mcp, addr, command, + (u8 *)&data->word, 2, + MCP2221_I2C_WR_DATA, 1); + } + break; + case I2C_SMBUS_BLOCK_DATA: + if (read_write == I2C_SMBUS_READ) { + ret = mcp_smbus_write(mcp, addr, command, NULL, + 0, MCP2221_I2C_WR_NO_STOP, 1); + if (ret) + goto exit; + + mcp->rxbuf_idx = 0; + mcp->rxbuf = data->block; + mcp->txbuf[0] = MCP2221_I2C_GET_DATA; + ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1); + if (ret) + goto exit; + } else { + if (!data->block[0]) { + ret = -EINVAL; + goto exit; + } + ret = mcp_smbus_write(mcp, addr, command, data->block, + data->block[0] + 1, + MCP2221_I2C_WR_DATA, 1); + } + break; + case I2C_SMBUS_I2C_BLOCK_DATA: + if (read_write == I2C_SMBUS_READ) { + ret = mcp_smbus_write(mcp, addr, command, NULL, + 0, MCP2221_I2C_WR_NO_STOP, 1); + if (ret) + goto exit; + + mcp->rxbuf_idx = 0; + mcp->rxbuf = data->block; + mcp->txbuf[0] = MCP2221_I2C_GET_DATA; + ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1); + if (ret) + goto exit; + } else { + if (!data->block[0]) { + ret = -EINVAL; + goto exit; + } + ret = mcp_smbus_write(mcp, addr, command, + &data->block[1], data->block[0], + MCP2221_I2C_WR_DATA, 1); + } + break; + case I2C_SMBUS_PROC_CALL: + ret = mcp_smbus_write(mcp, addr, command, + (u8 *)&data->word, + 2, MCP2221_I2C_WR_NO_STOP, 0); + if (ret) + goto exit; + + ret = mcp_i2c_smbus_read(mcp, NULL, + MCP2221_I2C_RD_RPT_START, + addr, 2, (u8 *)&data->word); + break; + case I2C_SMBUS_BLOCK_PROC_CALL: + ret = mcp_smbus_write(mcp, addr, command, data->block, + data->block[0] + 1, + MCP2221_I2C_WR_NO_STOP, 0); + if (ret) + goto exit; + + ret = mcp_i2c_smbus_read(mcp, NULL, + MCP2221_I2C_RD_RPT_START, + addr, I2C_SMBUS_BLOCK_MAX, + data->block); + break; + default: + dev_err(&mcp->adapter.dev, + "unsupported smbus transaction size:%d\n", size); + ret = -EOPNOTSUPP; + } + +exit: + hid_hw_power(mcp->hdev, PM_HINT_NORMAL); + mutex_unlock(&mcp->lock); + return ret; +} + +static u32 mcp_i2c_func(struct i2c_adapter *adapter) +{ + return I2C_FUNC_I2C | + I2C_FUNC_SMBUS_READ_BLOCK_DATA | + I2C_FUNC_SMBUS_BLOCK_PROC_CALL | + (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_PEC); +} + +static const struct i2c_algorithm mcp_i2c_algo = { + .master_xfer = mcp_i2c_xfer, + .smbus_xfer = mcp_smbus_xfer, + .functionality = mcp_i2c_func, +}; + +/* Gives current state of i2c engine inside mcp2221 */ +static int mcp_get_i2c_eng_state(struct mcp2221 *mcp, + u8 *data, u8 idx) +{ + int ret; + + switch (data[idx]) { + case MCP2221_I2C_WRADDRL_NACK: + case MCP2221_I2C_WRADDRL_SEND: + ret = -ENXIO; + break; + case MCP2221_I2C_START_TOUT: + case MCP2221_I2C_STOP_TOUT: + case MCP2221_I2C_WRADDRL_TOUT: + case MCP2221_I2C_WRDATA_TOUT: + ret = -ETIMEDOUT; + break; + case MCP2221_I2C_ENG_BUSY: + ret = -EAGAIN; + break; + case MCP2221_SUCCESS: + ret = 0x00; + break; + default: + ret = -EIO; + } + + return ret; +} + +/* + * MCP2221 uses interrupt endpoint for input reports. This function + * is called by HID layer when it receives i/p report from mcp2221, + * which is actually a response to the previously sent command. + * + * MCP2221A firmware specific return codes are parsed and 0 or + * appropriate negative error code is returned. Delayed response + * results in timeout error and stray reponses results in -EIO. + */ +static int mcp2221_raw_event(struct hid_device *hdev, + struct hid_report *report, u8 *data, int size) +{ + u8 *buf; + struct mcp2221 *mcp = hid_get_drvdata(hdev); + + switch (data[0]) { + + case MCP2221_I2C_WR_DATA: + case MCP2221_I2C_WR_NO_STOP: + case MCP2221_I2C_RD_DATA: + case MCP2221_I2C_RD_RPT_START: + switch (data[1]) { + case MCP2221_SUCCESS: + mcp->status = 0; + break; + default: + mcp->status = mcp_get_i2c_eng_state(mcp, data, 2); + } + complete(&mcp->wait_in_report); + break; + + case MCP2221_I2C_PARAM_OR_STATUS: + switch (data[1]) { + case MCP2221_SUCCESS: + if ((mcp->txbuf[3] == MCP2221_I2C_SET_SPEED) && + (data[3] != MCP2221_I2C_SET_SPEED)) { + mcp->status = -EAGAIN; + break; + } + if (data[20] & MCP2221_I2C_MASK_ADDR_NACK) { + mcp->status = -ENXIO; + break; + } + mcp->status = mcp_get_i2c_eng_state(mcp, data, 8); + break; + default: + mcp->status = -EIO; + } + complete(&mcp->wait_in_report); + break; + + case MCP2221_I2C_GET_DATA: + switch (data[1]) { + case MCP2221_SUCCESS: + if (data[2] == MCP2221_I2C_ADDR_NACK) { + mcp->status = -ENXIO; + break; + } + if (!mcp_get_i2c_eng_state(mcp, data, 2) + && (data[3] == 0)) { + mcp->status = 0; + break; + } + if (data[3] == 127) { + mcp->status = -EIO; + break; + } + if (data[2] == MCP2221_I2C_READ_COMPL) { + buf = mcp->rxbuf; + memcpy(&buf[mcp->rxbuf_idx], &data[4], data[3]); + mcp->rxbuf_idx = mcp->rxbuf_idx + data[3]; + mcp->status = 0; + break; + } + mcp->status = -EIO; + break; + default: + mcp->status = -EIO; + } + complete(&mcp->wait_in_report); + break; + + default: + mcp->status = -EIO; + complete(&mcp->wait_in_report); + } + + return 1; +} + +static int mcp2221_probe(struct hid_device *hdev, + const struct hid_device_id *id) +{ + int ret; + struct mcp2221 *mcp; + + mcp = devm_kzalloc(&hdev->dev, sizeof(*mcp), GFP_KERNEL); + if (!mcp) + return -ENOMEM; + + ret = hid_parse(hdev); + if (ret) { + hid_err(hdev, "can't parse reports\n"); + return ret; + } + + ret = hid_hw_start(hdev, HID_CONNECT_HIDRAW); + if (ret) { + hid_err(hdev, "can't start hardware\n"); + return ret; + } + + ret = hid_hw_open(hdev); + if (ret) { + hid_err(hdev, "can't open device\n"); + goto err_hstop; + } + + mutex_init(&mcp->lock); + init_completion(&mcp->wait_in_report); + hid_set_drvdata(hdev, mcp); + mcp->hdev = hdev; + + /* Set I2C bus clock diviser */ + if (i2c_clk_freq > 400) + i2c_clk_freq = 400; + if (i2c_clk_freq < 50) + i2c_clk_freq = 50; + mcp->cur_i2c_clk_div = (12000000 / (i2c_clk_freq * 1000)) - 3; + + mcp->adapter.owner = THIS_MODULE; + mcp->adapter.class = I2C_CLASS_HWMON; + mcp->adapter.algo = &mcp_i2c_algo; + mcp->adapter.retries = 1; + mcp->adapter.dev.parent = &hdev->dev; + snprintf(mcp->adapter.name, sizeof(mcp->adapter.name), + "MCP2221 usb-i2c bridge on hidraw%d", + ((struct hidraw *)hdev->hidraw)->minor); + + ret = i2c_add_adapter(&mcp->adapter); + if (ret) { + hid_err(hdev, "can't add usb-i2c adapter: %d\n", ret); + goto err_i2c; + } + i2c_set_adapdata(&mcp->adapter, mcp); + + return 0; + +err_i2c: + hid_hw_close(mcp->hdev); +err_hstop: + hid_hw_stop(mcp->hdev); + return ret; +} + +static void mcp2221_remove(struct hid_device *hdev) +{ + struct mcp2221 *mcp = hid_get_drvdata(hdev); + + i2c_del_adapter(&mcp->adapter); + hid_hw_close(mcp->hdev); + hid_hw_stop(mcp->hdev); +} + +static const struct hid_device_id mcp2221_devices[] = { + { HID_USB_DEVICE(USB_VENDOR_ID_MICROCHIP, USB_DEVICE_ID_MCP2221) }, + { } +}; +MODULE_DEVICE_TABLE(hid, mcp2221_devices); + +static struct hid_driver mcp2221_driver = { + .name = "mcp2221", + .id_table = mcp2221_devices, + .probe = mcp2221_probe, + .remove = mcp2221_remove, + .raw_event = mcp2221_raw_event, +}; + +/* Register with HID core */ +module_hid_driver(mcp2221_driver); + +MODULE_AUTHOR("Rishi Gupta <gupt21@gmail.com>"); +MODULE_DESCRIPTION("MCP2221 Microchip HID USB to I2C master bridge"); +MODULE_LICENSE("GPL v2");
MCP2221 is a USB HID to I2C/SMbus host bridge device. This commit implements i2c and smbus host adapter support. 7-bit address and i2c multi-message transaction is also supported. Signed-off-by: Rishi Gupta <gupt21@gmail.com> --- Changes in v3: * Removed all direct USB related references * Replaced defines with enum * Replaced HID_CONNECT_DEFAULT with HID_CONNECT_HIDRAW * Removed depends on HIDRAW in Kconfig * Used memset wherever possible * Emit more clear log - unsupported multi-msg i2c transaction * Removed mcp2221 entry from hid-quirk.c * Removed module parameter to set i2c bus speed MAINTAINERS | 7 + drivers/hid/Kconfig | 10 + drivers/hid/Makefile | 1 + drivers/hid/hid-ids.h | 1 + drivers/hid/hid-mcp2221.c | 742 ++++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 761 insertions(+) create mode 100644 drivers/hid/hid-mcp2221.c