| Message ID | 1356434755-13702-1-git-send-email-ch.naveen@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, On Tue, Dec 25, 2012 at 04:55:54PM +0530, Naveen Krishna Chatradhi wrote: > Adds support for High Speed I2C driver found in Exynos5 and later > SoCs from Samsung. This driver currently supports Auto mode. > > Driver only supports Device Tree method. > > Signed-off-by: Taekgyun Ko <taeggyun.ko@samsung.com> > Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com> > --- > Changes since v1: > Fixed the comments from Felipe Balbi and Thomas Abraham. > > drivers/i2c/busses/Kconfig | 7 + > drivers/i2c/busses/Makefile | 1 + > drivers/i2c/busses/i2c-exynos5.c | 652 ++++++++++++++++++++++++++++++++++++++ > drivers/i2c/busses/i2c-exynos5.h | 102 ++++++ > 4 files changed, 762 insertions(+) > create mode 100644 drivers/i2c/busses/i2c-exynos5.c > create mode 100644 drivers/i2c/busses/i2c-exynos5.h > > diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig > index bdca511..4caea76 100644 > --- a/drivers/i2c/busses/Kconfig > +++ b/drivers/i2c/busses/Kconfig > @@ -618,6 +618,13 @@ config I2C_S3C2410 > Say Y here to include support for I2C controller in the > Samsung SoCs. > > +config I2C_EXYNOS5 > + tristate "Exynos5 high-speed I2C driver" > + depends on ARCH_EXYNOS5 > + help > + Say Y here to include support for High-speed I2C controller in the > + Exynos5 based Samsung SoCs. > + > config I2C_S6000 > tristate "S6000 I2C support" > depends on XTENSA_VARIANT_S6000 > diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile > index 6181f3f..4b1548c 100644 > --- a/drivers/i2c/busses/Makefile > +++ b/drivers/i2c/busses/Makefile > @@ -61,6 +61,7 @@ obj-$(CONFIG_I2C_PUV3) += i2c-puv3.o > obj-$(CONFIG_I2C_PXA) += i2c-pxa.o > obj-$(CONFIG_I2C_PXA_PCI) += i2c-pxa-pci.o > obj-$(CONFIG_I2C_S3C2410) += i2c-s3c2410.o > +obj-$(CONFIG_I2C_EXYNOS5) += i2c-exynos5.o > obj-$(CONFIG_I2C_S6000) += i2c-s6000.o > obj-$(CONFIG_I2C_SH7760) += i2c-sh7760.o > obj-$(CONFIG_I2C_SH_MOBILE) += i2c-sh_mobile.o > diff --git a/drivers/i2c/busses/i2c-exynos5.c b/drivers/i2c/busses/i2c-exynos5.c > new file mode 100644 > index 0000000..7614f60 > --- /dev/null > +++ b/drivers/i2c/busses/i2c-exynos5.c > @@ -0,0 +1,652 @@ > +/* linux/drivers/i2c/busses/i2c-exynos5.c no need for the full path. Generally this would look like: * i2c-exynos5.c - Samsung Exynos 5 I2C Controller Driver no strong feelings however. > + * Copyright (C) 2012 Samsung Electronics Co., Ltd. > + * > + * High speed I2C controller driver > + * for Exynos5 and later SoCs from Samsung. > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > +*/ > + > +#include <linux/kernel.h> > +#include <linux/module.h> > + > +#include <linux/i2c.h> > +#include <linux/init.h> > +#include <linux/time.h> > +#include <linux/interrupt.h> > +#include <linux/delay.h> > +#include <linux/errno.h> > +#include <linux/err.h> > +#include <linux/platform_device.h> > +#include <linux/pm_runtime.h> > +#include <linux/clk.h> > +#include <linux/slab.h> > +#include <linux/io.h> > +#include <linux/of_address.h> > +#include <linux/of_gpio.h> > +#include <linux/of_irq.h> > +#include <linux/of_i2c.h> > + > +#include "i2c-exynos5.h" it doesn't look like this header is even needed. All those macros could be defined here in the C-source file which is the only user. > +#define EXYNOS5_I2C_TIMEOUT (msecs_to_jiffies(1000)) > + > +/* timeout for pm runtime autosuspend */ > +#define EXYNOS5_I2C_PM_TIMEOUT 1000 /* ms */ > + > +struct exynos5_i2c { > + struct i2c_adapter adap; > + unsigned int suspended:1; > + > + struct i2c_msg *msg; > + unsigned int msg_idx; > + struct completion msg_complete; > + unsigned int msg_ptr; > + > + unsigned int irq; > + > + void __iomem *regs; > + struct clk *clk; > + struct device *dev; > + int gpios[2]; > + > + int bus_num; > + int speed_mode; > +}; > + > +static const struct of_device_id exynos5_i2c_match[] = { > + { .compatible = "samsung,exynos5-hsi2c" }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, exynos5_i2c_match); > + > +/* TODO: Should go to debugfs */ > +static inline void dump_i2c_register(struct exynos5_i2c *i2c) > +{ > + dev_vdbg(i2c->dev, "Register dump(%d) :\n %x\n %x\n %x\n %x\n" > + " %x\n %x\n %x\n %x\n %x\n" > + " %x\n %x\n %x\n %x\n %x\n" > + " %x\n %x\n %x\n %x\n %x\n" > + " %x\n %x\n %x\n %x\n %x\n", > + i2c->suspended, > + readl(i2c->regs + HSI2C_CTL), > + readl(i2c->regs + HSI2C_FIFO_CTL), > + readl(i2c->regs + HSI2C_TRAILIG_CTL), > + readl(i2c->regs + HSI2C_CLK_CTL), > + readl(i2c->regs + HSI2C_CLK_SLOT), > + readl(i2c->regs + HSI2C_INT_ENABLE), > + readl(i2c->regs + HSI2C_INT_STATUS), > + readl(i2c->regs + HSI2C_ERR_STATUS), > + readl(i2c->regs + HSI2C_FIFO_STATUS), > + readl(i2c->regs + HSI2C_TX_DATA), > + readl(i2c->regs + HSI2C_RX_DATA), > + readl(i2c->regs + HSI2C_CONF), > + readl(i2c->regs + HSI2C_AUTO_CONF), > + readl(i2c->regs + HSI2C_TIMEOUT), > + readl(i2c->regs + HSI2C_MANUAL_CMD), > + readl(i2c->regs + HSI2C_TRANS_STATUS), > + readl(i2c->regs + HSI2C_TIMING_HS1), > + readl(i2c->regs + HSI2C_TIMING_HS2), > + readl(i2c->regs + HSI2C_TIMING_HS3), > + readl(i2c->regs + HSI2C_TIMING_FS1), > + readl(i2c->regs + HSI2C_TIMING_FS2), > + readl(i2c->regs + HSI2C_TIMING_FS3), > + readl(i2c->regs + HSI2C_TIMING_SLA), > + readl(i2c->regs + HSI2C_ADDR)); > +} NAK, please add debugfs support already. This will be here for a long time otherwise > +static inline void exynos5_i2c_stop(struct exynos5_i2c *i2c, int ret) no need for inline, GCC will handle that. Also, this prototype looks awkward, you're passing caller's return code to be checked here... it's weird, to say the least. > +{ > + dev_dbg(i2c->dev, "STOP\n"); I would call this dev_vdbg() > + > + i2c->msg_idx++; > + if (ret) > + i2c->msg_idx = ret; > + > + /* Disable interrrupts */ > + writel(0, i2c->regs + HSI2C_INT_ENABLE); > + complete(&i2c->msg_complete); > +} > + > +static void exynos5_i2c_en_timeout(struct exynos5_i2c *i2c) > +{ > + unsigned long i2c_timeout = readl(i2c->regs + HSI2C_TIMEOUT); > + > + /* Clear to enable Timeout */ > + i2c_timeout &= ~HSI2C_TIMEOUT_EN; > + writel(i2c_timeout, i2c->regs + HSI2C_TIMEOUT); > +} > + > +static void exynos5_i2c_master_run(struct exynos5_i2c *i2c) > +{ > + /* Start data transfer in Master mode */ > + u32 i2c_auto_conf = readl(i2c->regs + HSI2C_AUTO_CONF); > + i2c_auto_conf |= HSI2C_MASTER_RUN; > + writel(i2c_auto_conf, i2c->regs + HSI2C_AUTO_CONF); > +} > + > +/* exynos5_i2c_set_bus > + * > + * get the i2c bus for a master/slave transaction > + */ multiline comment style is wrong. > +static int exynos5_i2c_set_bus(struct exynos5_i2c *i2c, int master) this function is only called with master set to 1, do you even need that argument ? Do you have some out-of-tree code for supporting slave mode ? Please remove 'slave' support completely as that's not supported in mainline as of today, if you need slave support, then add it to the framework first. > +{ > + unsigned long t_status; > + int timeout = 400; > + > + while (timeout-- > 0) { > + t_status = readl(i2c->regs + HSI2C_TRANS_STATUS); > + > + if (master) { > + if (!(t_status & HSI2C_MASTER_BUSY)) > + return 0; > + } else { > + if (!(t_status & HSI2C_SLAVE_BUSY)) > + return 0; > + } > + > + msleep(20); > + } > + > + return -ETIMEDOUT; > +} > + > +/* exynos5_i2c_irq > + * > + * top level IRQ servicing routine > + */ multiline comment style is wrong. > +static irqreturn_t exynos5_i2c_irq(int irqno, void *dev_id) > +{ > + struct exynos5_i2c *i2c = dev_id; > + unsigned long t_stat; > + unsigned char byte; > + > + t_stat = readl(i2c->regs + HSI2C_TRANS_STATUS); > + > + if (t_stat & HSI2C_TRANS_ABORT) { > + /* deal with arbitration loss */ > + dev_err(i2c->dev, "deal with arbitration loss\n"); > + goto out; > + } > + if (i2c->msg->flags & I2C_M_RD) { > + if (t_stat & HSI2C_TRANS_DONE) { > + dev_dbg(i2c->dev, "Device found."); > + while ((readl(i2c->regs + HSI2C_FIFO_STATUS) & > + HSI2C_RX_FIFO_EMPTY) == 0) { > + byte = readl(i2c->regs + HSI2C_RX_DATA); > + dev_dbg(i2c->dev, "read rx_data = %x", byte); > + i2c->msg->buf[i2c->msg_ptr++] = byte; > + } > + } else if (t_stat & HSI2C_NO_DEV) { > + dev_dbg(i2c->dev, "No device found."); > + exynos5_i2c_stop(i2c, -ENXIO); > + } else if (t_stat & HSI2C_NO_DEV_ACK && > + !(i2c->msg->flags & I2C_M_IGNORE_NAK)) { > + dev_dbg(i2c->dev, "No device Ack."); > + exynos5_i2c_stop(i2c, -ENXIO); > + } > + } else { > + byte = i2c->msg->buf[i2c->msg_ptr++]; > + dev_dbg(i2c->dev, "write tx_data = %x ", byte); > + writel(byte, i2c->regs + HSI2C_TX_DATA); > + } > + > + if (i2c->msg_ptr >= i2c->msg->len) > + exynos5_i2c_stop(i2c, 0); > + > + out: > + /* Set those bits to clear them */ > + writel(readl(i2c->regs + HSI2C_INT_STATUS), > + i2c->regs + HSI2C_INT_STATUS); > + > + return IRQ_HANDLED; > +} > + > +static void exynos5_i2c_message_start(struct exynos5_i2c *i2c, > + struct i2c_msg *msgs) > +{ > + unsigned long usi_ctl = HSI2C_FUNC_MODE_I2C | HSI2C_MASTER; > + unsigned long i2c_auto_conf; > + unsigned long i2c_addr = ((msgs->addr & 0x7f) << 10); > + unsigned long usi_int_en = 0; > + > + exynos5_i2c_en_timeout(i2c); > + > + if (msgs->flags & I2C_M_RD) { > + usi_ctl &= ~HSI2C_TXCHON; > + usi_ctl |= HSI2C_RXCHON; > + > + i2c_auto_conf |= HSI2C_READ_WRITE; > + > + usi_int_en |= (HSI2C_INT_RX_ALMOSTFULL_EN | > + HSI2C_INT_TRAILING_EN); > + } else { > + usi_ctl &= ~HSI2C_RXCHON; > + usi_ctl |= HSI2C_TXCHON; > + > + i2c_auto_conf &= ~HSI2C_READ_WRITE; > + > + usi_int_en |= HSI2C_INT_TX_ALMOSTEMPTY_EN; > + } > + > + writel(i2c_addr, i2c->regs + HSI2C_ADDR); > + writel(usi_ctl, i2c->regs + HSI2C_CTL); > + > + i2c_auto_conf |= i2c->msg->len; > + i2c_auto_conf |= HSI2C_STOP_AFTER_TRANS; > + writel(i2c_auto_conf, i2c->regs + HSI2C_AUTO_CONF); > + > + exynos5_i2c_master_run(i2c); > + > + /* Enable appropriate interrupts */ > + writel(usi_int_en, i2c->regs + HSI2C_INT_ENABLE); > +} > + > +static int exynos5_i2c_doxfer(struct exynos5_i2c *i2c, struct i2c_msg *msgs) > +{ > + unsigned long timeout; > + > + if (i2c->suspended) { > + dev_err(i2c->dev, "HS-I2C is not initialzed.\n"); > + return -EIO; > + } > + > + if (exynos5_i2c_set_bus(i2c, 1)) { > + dev_err(i2c->dev, "cannot get bus, Master busy.\n"); > + return -EAGAIN; > + } > + > + i2c->msg = msgs; > + i2c->msg_ptr = 0; > + i2c->msg_idx = 0; > + > + INIT_COMPLETION(i2c->msg_complete); > + > + exynos5_i2c_message_start(i2c, msgs); > + > + timeout = wait_for_completion_timeout(&i2c->msg_complete, > + EXYNOS5_I2C_TIMEOUT); > + > + if (timeout == 0) > + dev_dbg(i2c->dev, "timeout\n"); > + else if (i2c->msg_idx != msgs->len) > + dev_dbg(i2c->dev, "incomplete xfer (%d)\n", i2c->msg_idx); > + > + return i2c->msg_idx; > +} > + > +static int exynos5_i2c_xfer(struct i2c_adapter *adap, > + struct i2c_msg *msgs, int num) > +{ > + struct exynos5_i2c *i2c = (struct exynos5_i2c *)adap->algo_data; > + int retry, i; > + int ret; > + > + ret = pm_runtime_get_sync(i2c->dev); > + if (IS_ERR_VALUE(ret)) > + goto out; > + > + clk_prepare_enable(i2c->clk); > + > + for (retry = 0; retry < adap->retries; retry++) { > + for (i = 0; i < num; i++) { > + ret = exynos5_i2c_doxfer(i2c, msgs); > + msgs++; > + > + if (ret == -EAGAIN) > + break; > + } > + if (i == num) { > + clk_disable_unprepare(i2c->clk); > + ret = i2c->msg_idx; > + goto out; > + } why don't you just move this to the out label ? > + dev_dbg(i2c->dev, "retrying transfer (%d)\n", retry); > + > + udelay(100); > + } > + > + ret = -EREMOTEIO; > + clk_disable_unprepare(i2c->clk); > + out: > + pm_runtime_mark_last_busy(i2c->dev); > + pm_runtime_put_autosuspend(i2c->dev); > + return ret; > +} > + > +static u32 exynos5_i2c_func(struct i2c_adapter *adap) > +{ > + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; > +} > + > +static const struct i2c_algorithm exynos5_i2c_algorithm = { > + .master_xfer = exynos5_i2c_xfer, > + .functionality = exynos5_i2c_func, > +}; > + > +static int exynos5_i2c_set_timing(struct exynos5_i2c *i2c, int speed_mode) > +{ > + unsigned long i2c_timing_s1; > + unsigned long i2c_timing_s2; > + unsigned long i2c_timing_s3; > + unsigned long i2c_timing_sla; > + unsigned int op_clk; > + unsigned int clkin = clk_get_rate(i2c->clk); > + unsigned int n_clkdiv; > + unsigned int t_start_su, t_start_hd; > + unsigned int t_stop_su; > + unsigned int t_data_su, t_data_hd; > + unsigned int t_scl_l, t_scl_h; > + unsigned int t_sr_release; > + unsigned int t_ftl_cycle; > + unsigned int i = 0, utemp0 = 0, utemp1 = 0, utemp2 = 0; > + > + if (speed_mode == HSI2C_HIGH_SPD) > + op_clk = HSI2C_HS_TX_CLOCK; > + else > + op_clk = HSI2C_FS_TX_CLOCK; > + > + /* FPCLK / FI2C = > + * (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2) + 8 + 2 * FLT_CYCLE > + * uTemp0 = (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2) > + * uTemp1 = (TSCLK_L + TSCLK_H + 2) > + * uTemp2 = TSCLK_L + TSCLK_H > + */ wrong indentation (back to my vacations now)
Hello Balbi, On 28 December 2012 04:27, Felipe Balbi <balbi@ti.com> wrote: > Hi, > > On Tue, Dec 25, 2012 at 04:55:54PM +0530, Naveen Krishna Chatradhi wrote: >> Adds support for High Speed I2C driver found in Exynos5 and later >> SoCs from Samsung. This driver currently supports Auto mode. >> >> Driver only supports Device Tree method. >> >> Signed-off-by: Taekgyun Ko <taeggyun.ko@samsung.com> >> Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com> >> --- >> Changes since v1: >> Fixed the comments from Felipe Balbi and Thomas Abraham. >> >> drivers/i2c/busses/Kconfig | 7 + >> drivers/i2c/busses/Makefile | 1 + >> drivers/i2c/busses/i2c-exynos5.c | 652 ++++++++++++++++++++++++++++++++++++++ >> drivers/i2c/busses/i2c-exynos5.h | 102 ++++++ >> 4 files changed, 762 insertions(+) >> create mode 100644 drivers/i2c/busses/i2c-exynos5.c >> create mode 100644 drivers/i2c/busses/i2c-exynos5.h >> >> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig >> index bdca511..4caea76 100644 >> --- a/drivers/i2c/busses/Kconfig >> +++ b/drivers/i2c/busses/Kconfig >> @@ -618,6 +618,13 @@ config I2C_S3C2410 >> Say Y here to include support for I2C controller in the >> Samsung SoCs. >> >> +config I2C_EXYNOS5 >> + tristate "Exynos5 high-speed I2C driver" >> + depends on ARCH_EXYNOS5 >> + help >> + Say Y here to include support for High-speed I2C controller in the >> + Exynos5 based Samsung SoCs. >> + >> config I2C_S6000 >> tristate "S6000 I2C support" >> depends on XTENSA_VARIANT_S6000 >> diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile >> index 6181f3f..4b1548c 100644 >> --- a/drivers/i2c/busses/Makefile >> +++ b/drivers/i2c/busses/Makefile >> @@ -61,6 +61,7 @@ obj-$(CONFIG_I2C_PUV3) += i2c-puv3.o >> obj-$(CONFIG_I2C_PXA) += i2c-pxa.o >> obj-$(CONFIG_I2C_PXA_PCI) += i2c-pxa-pci.o >> obj-$(CONFIG_I2C_S3C2410) += i2c-s3c2410.o >> +obj-$(CONFIG_I2C_EXYNOS5) += i2c-exynos5.o >> obj-$(CONFIG_I2C_S6000) += i2c-s6000.o >> obj-$(CONFIG_I2C_SH7760) += i2c-sh7760.o >> obj-$(CONFIG_I2C_SH_MOBILE) += i2c-sh_mobile.o >> diff --git a/drivers/i2c/busses/i2c-exynos5.c b/drivers/i2c/busses/i2c-exynos5.c >> new file mode 100644 >> index 0000000..7614f60 >> --- /dev/null >> +++ b/drivers/i2c/busses/i2c-exynos5.c >> @@ -0,0 +1,652 @@ >> +/* linux/drivers/i2c/busses/i2c-exynos5.c > > no need for the full path. Generally this would look like: > > * i2c-exynos5.c - Samsung Exynos 5 I2C Controller Driver > > no strong feelings however. > >> + * Copyright (C) 2012 Samsung Electronics Co., Ltd. >> + * >> + * High speed I2C controller driver >> + * for Exynos5 and later SoCs from Samsung. >> + * >> + * This program is free software; you can redistribute it and/or modify >> + * it under the terms of the GNU General Public License version 2 as >> + * published by the Free Software Foundation. >> +*/ >> + >> +#include <linux/kernel.h> >> +#include <linux/module.h> >> + >> +#include <linux/i2c.h> >> +#include <linux/init.h> >> +#include <linux/time.h> >> +#include <linux/interrupt.h> >> +#include <linux/delay.h> >> +#include <linux/errno.h> >> +#include <linux/err.h> >> +#include <linux/platform_device.h> >> +#include <linux/pm_runtime.h> >> +#include <linux/clk.h> >> +#include <linux/slab.h> >> +#include <linux/io.h> >> +#include <linux/of_address.h> >> +#include <linux/of_gpio.h> >> +#include <linux/of_irq.h> >> +#include <linux/of_i2c.h> >> + >> +#include "i2c-exynos5.h" > > it doesn't look like this header is even needed. All those macros could > be defined here in the C-source file which is the only user. > >> +#define EXYNOS5_I2C_TIMEOUT (msecs_to_jiffies(1000)) >> + >> +/* timeout for pm runtime autosuspend */ >> +#define EXYNOS5_I2C_PM_TIMEOUT 1000 /* ms */ >> + >> +struct exynos5_i2c { >> + struct i2c_adapter adap; >> + unsigned int suspended:1; >> + >> + struct i2c_msg *msg; >> + unsigned int msg_idx; >> + struct completion msg_complete; >> + unsigned int msg_ptr; >> + >> + unsigned int irq; >> + >> + void __iomem *regs; >> + struct clk *clk; >> + struct device *dev; >> + int gpios[2]; >> + >> + int bus_num; >> + int speed_mode; >> +}; >> + >> +static const struct of_device_id exynos5_i2c_match[] = { >> + { .compatible = "samsung,exynos5-hsi2c" }, >> + {}, >> +}; >> +MODULE_DEVICE_TABLE(of, exynos5_i2c_match); >> + >> +/* TODO: Should go to debugfs */ >> +static inline void dump_i2c_register(struct exynos5_i2c *i2c) >> +{ >> + dev_vdbg(i2c->dev, "Register dump(%d) :\n %x\n %x\n %x\n %x\n" >> + " %x\n %x\n %x\n %x\n %x\n" >> + " %x\n %x\n %x\n %x\n %x\n" >> + " %x\n %x\n %x\n %x\n %x\n" >> + " %x\n %x\n %x\n %x\n %x\n", >> + i2c->suspended, >> + readl(i2c->regs + HSI2C_CTL), >> + readl(i2c->regs + HSI2C_FIFO_CTL), >> + readl(i2c->regs + HSI2C_TRAILIG_CTL), >> + readl(i2c->regs + HSI2C_CLK_CTL), >> + readl(i2c->regs + HSI2C_CLK_SLOT), >> + readl(i2c->regs + HSI2C_INT_ENABLE), >> + readl(i2c->regs + HSI2C_INT_STATUS), >> + readl(i2c->regs + HSI2C_ERR_STATUS), >> + readl(i2c->regs + HSI2C_FIFO_STATUS), >> + readl(i2c->regs + HSI2C_TX_DATA), >> + readl(i2c->regs + HSI2C_RX_DATA), >> + readl(i2c->regs + HSI2C_CONF), >> + readl(i2c->regs + HSI2C_AUTO_CONF), >> + readl(i2c->regs + HSI2C_TIMEOUT), >> + readl(i2c->regs + HSI2C_MANUAL_CMD), >> + readl(i2c->regs + HSI2C_TRANS_STATUS), >> + readl(i2c->regs + HSI2C_TIMING_HS1), >> + readl(i2c->regs + HSI2C_TIMING_HS2), >> + readl(i2c->regs + HSI2C_TIMING_HS3), >> + readl(i2c->regs + HSI2C_TIMING_FS1), >> + readl(i2c->regs + HSI2C_TIMING_FS2), >> + readl(i2c->regs + HSI2C_TIMING_FS3), >> + readl(i2c->regs + HSI2C_TIMING_SLA), >> + readl(i2c->regs + HSI2C_ADDR)); >> +} > > NAK, please add debugfs support already. This will be here for a long > time otherwise Actually patch 2/2 does the same, posted them separately for RFC > >> +static inline void exynos5_i2c_stop(struct exynos5_i2c *i2c, int ret) > > no need for inline, GCC will handle that. Also, this prototype looks > awkward, you're passing caller's return code to be checked here... it's > weird, to say the least. > >> +{ >> + dev_dbg(i2c->dev, "STOP\n"); > > I would call this dev_vdbg() > >> + >> + i2c->msg_idx++; >> + if (ret) >> + i2c->msg_idx = ret; >> + >> + /* Disable interrrupts */ >> + writel(0, i2c->regs + HSI2C_INT_ENABLE); >> + complete(&i2c->msg_complete); >> +} >> + >> +static void exynos5_i2c_en_timeout(struct exynos5_i2c *i2c) >> +{ >> + unsigned long i2c_timeout = readl(i2c->regs + HSI2C_TIMEOUT); >> + >> + /* Clear to enable Timeout */ >> + i2c_timeout &= ~HSI2C_TIMEOUT_EN; >> + writel(i2c_timeout, i2c->regs + HSI2C_TIMEOUT); >> +} >> + >> +static void exynos5_i2c_master_run(struct exynos5_i2c *i2c) >> +{ >> + /* Start data transfer in Master mode */ >> + u32 i2c_auto_conf = readl(i2c->regs + HSI2C_AUTO_CONF); >> + i2c_auto_conf |= HSI2C_MASTER_RUN; >> + writel(i2c_auto_conf, i2c->regs + HSI2C_AUTO_CONF); >> +} >> + >> +/* exynos5_i2c_set_bus >> + * >> + * get the i2c bus for a master/slave transaction >> + */ > > multiline comment style is wrong. > >> +static int exynos5_i2c_set_bus(struct exynos5_i2c *i2c, int master) > > this function is only called with master set to 1, do you even need that > argument ? Do you have some out-of-tree code for supporting slave mode ? > > Please remove 'slave' support completely as that's not supported in > mainline as of today, if you need slave support, then add it to the > framework first. Will remove slave stuff, I don't plans for the as of now. > >> +{ >> + unsigned long t_status; >> + int timeout = 400; >> + >> + while (timeout-- > 0) { >> + t_status = readl(i2c->regs + HSI2C_TRANS_STATUS); >> + >> + if (master) { >> + if (!(t_status & HSI2C_MASTER_BUSY)) >> + return 0; >> + } else { >> + if (!(t_status & HSI2C_SLAVE_BUSY)) >> + return 0; >> + } >> + >> + msleep(20); >> + } >> + >> + return -ETIMEDOUT; >> +} >> + >> +/* exynos5_i2c_irq >> + * >> + * top level IRQ servicing routine >> + */ > > multiline comment style is wrong. > >> +static irqreturn_t exynos5_i2c_irq(int irqno, void *dev_id) >> +{ >> + struct exynos5_i2c *i2c = dev_id; >> + unsigned long t_stat; >> + unsigned char byte; >> + >> + t_stat = readl(i2c->regs + HSI2C_TRANS_STATUS); >> + >> + if (t_stat & HSI2C_TRANS_ABORT) { >> + /* deal with arbitration loss */ >> + dev_err(i2c->dev, "deal with arbitration loss\n"); >> + goto out; >> + } >> + if (i2c->msg->flags & I2C_M_RD) { >> + if (t_stat & HSI2C_TRANS_DONE) { >> + dev_dbg(i2c->dev, "Device found."); >> + while ((readl(i2c->regs + HSI2C_FIFO_STATUS) & >> + HSI2C_RX_FIFO_EMPTY) == 0) { >> + byte = readl(i2c->regs + HSI2C_RX_DATA); >> + dev_dbg(i2c->dev, "read rx_data = %x", byte); >> + i2c->msg->buf[i2c->msg_ptr++] = byte; >> + } >> + } else if (t_stat & HSI2C_NO_DEV) { >> + dev_dbg(i2c->dev, "No device found."); >> + exynos5_i2c_stop(i2c, -ENXIO); >> + } else if (t_stat & HSI2C_NO_DEV_ACK && >> + !(i2c->msg->flags & I2C_M_IGNORE_NAK)) { >> + dev_dbg(i2c->dev, "No device Ack."); >> + exynos5_i2c_stop(i2c, -ENXIO); >> + } >> + } else { >> + byte = i2c->msg->buf[i2c->msg_ptr++]; >> + dev_dbg(i2c->dev, "write tx_data = %x ", byte); >> + writel(byte, i2c->regs + HSI2C_TX_DATA); >> + } >> + >> + if (i2c->msg_ptr >= i2c->msg->len) >> + exynos5_i2c_stop(i2c, 0); >> + >> + out: >> + /* Set those bits to clear them */ >> + writel(readl(i2c->regs + HSI2C_INT_STATUS), >> + i2c->regs + HSI2C_INT_STATUS); >> + >> + return IRQ_HANDLED; >> +} >> + >> +static void exynos5_i2c_message_start(struct exynos5_i2c *i2c, >> + struct i2c_msg *msgs) >> +{ >> + unsigned long usi_ctl = HSI2C_FUNC_MODE_I2C | HSI2C_MASTER; >> + unsigned long i2c_auto_conf; >> + unsigned long i2c_addr = ((msgs->addr & 0x7f) << 10); >> + unsigned long usi_int_en = 0; >> + >> + exynos5_i2c_en_timeout(i2c); >> + >> + if (msgs->flags & I2C_M_RD) { >> + usi_ctl &= ~HSI2C_TXCHON; >> + usi_ctl |= HSI2C_RXCHON; >> + >> + i2c_auto_conf |= HSI2C_READ_WRITE; >> + >> + usi_int_en |= (HSI2C_INT_RX_ALMOSTFULL_EN | >> + HSI2C_INT_TRAILING_EN); >> + } else { >> + usi_ctl &= ~HSI2C_RXCHON; >> + usi_ctl |= HSI2C_TXCHON; >> + >> + i2c_auto_conf &= ~HSI2C_READ_WRITE; >> + >> + usi_int_en |= HSI2C_INT_TX_ALMOSTEMPTY_EN; >> + } >> + >> + writel(i2c_addr, i2c->regs + HSI2C_ADDR); >> + writel(usi_ctl, i2c->regs + HSI2C_CTL); >> + >> + i2c_auto_conf |= i2c->msg->len; >> + i2c_auto_conf |= HSI2C_STOP_AFTER_TRANS; >> + writel(i2c_auto_conf, i2c->regs + HSI2C_AUTO_CONF); >> + >> + exynos5_i2c_master_run(i2c); >> + >> + /* Enable appropriate interrupts */ >> + writel(usi_int_en, i2c->regs + HSI2C_INT_ENABLE); >> +} >> + >> +static int exynos5_i2c_doxfer(struct exynos5_i2c *i2c, struct i2c_msg *msgs) >> +{ >> + unsigned long timeout; >> + >> + if (i2c->suspended) { >> + dev_err(i2c->dev, "HS-I2C is not initialzed.\n"); >> + return -EIO; >> + } >> + >> + if (exynos5_i2c_set_bus(i2c, 1)) { >> + dev_err(i2c->dev, "cannot get bus, Master busy.\n"); >> + return -EAGAIN; >> + } >> + >> + i2c->msg = msgs; >> + i2c->msg_ptr = 0; >> + i2c->msg_idx = 0; >> + >> + INIT_COMPLETION(i2c->msg_complete); >> + >> + exynos5_i2c_message_start(i2c, msgs); >> + >> + timeout = wait_for_completion_timeout(&i2c->msg_complete, >> + EXYNOS5_I2C_TIMEOUT); >> + >> + if (timeout == 0) >> + dev_dbg(i2c->dev, "timeout\n"); >> + else if (i2c->msg_idx != msgs->len) >> + dev_dbg(i2c->dev, "incomplete xfer (%d)\n", i2c->msg_idx); >> + >> + return i2c->msg_idx; >> +} >> + >> +static int exynos5_i2c_xfer(struct i2c_adapter *adap, >> + struct i2c_msg *msgs, int num) >> +{ >> + struct exynos5_i2c *i2c = (struct exynos5_i2c *)adap->algo_data; >> + int retry, i; >> + int ret; >> + >> + ret = pm_runtime_get_sync(i2c->dev); >> + if (IS_ERR_VALUE(ret)) >> + goto out; >> + >> + clk_prepare_enable(i2c->clk); >> + >> + for (retry = 0; retry < adap->retries; retry++) { >> + for (i = 0; i < num; i++) { >> + ret = exynos5_i2c_doxfer(i2c, msgs); >> + msgs++; >> + >> + if (ret == -EAGAIN) >> + break; >> + } >> + if (i == num) { >> + clk_disable_unprepare(i2c->clk); >> + ret = i2c->msg_idx; >> + goto out; >> + } > > why don't you just move this to the out label ? Moving this to label, din't look so clean to me.. > >> + dev_dbg(i2c->dev, "retrying transfer (%d)\n", retry); >> + >> + udelay(100); >> + } >> + >> + ret = -EREMOTEIO; >> + clk_disable_unprepare(i2c->clk); >> + out: >> + pm_runtime_mark_last_busy(i2c->dev); >> + pm_runtime_put_autosuspend(i2c->dev); >> + return ret; >> +} >> + >> +static u32 exynos5_i2c_func(struct i2c_adapter *adap) >> +{ >> + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; >> +} >> + >> +static const struct i2c_algorithm exynos5_i2c_algorithm = { >> + .master_xfer = exynos5_i2c_xfer, >> + .functionality = exynos5_i2c_func, >> +}; >> + >> +static int exynos5_i2c_set_timing(struct exynos5_i2c *i2c, int speed_mode) >> +{ >> + unsigned long i2c_timing_s1; >> + unsigned long i2c_timing_s2; >> + unsigned long i2c_timing_s3; >> + unsigned long i2c_timing_sla; >> + unsigned int op_clk; >> + unsigned int clkin = clk_get_rate(i2c->clk); >> + unsigned int n_clkdiv; >> + unsigned int t_start_su, t_start_hd; >> + unsigned int t_stop_su; >> + unsigned int t_data_su, t_data_hd; >> + unsigned int t_scl_l, t_scl_h; >> + unsigned int t_sr_release; >> + unsigned int t_ftl_cycle; >> + unsigned int i = 0, utemp0 = 0, utemp1 = 0, utemp2 = 0; >> + >> + if (speed_mode == HSI2C_HIGH_SPD) >> + op_clk = HSI2C_HS_TX_CLOCK; >> + else >> + op_clk = HSI2C_FS_TX_CLOCK; >> + >> + /* FPCLK / FI2C = >> + * (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2) + 8 + 2 * FLT_CYCLE >> + * uTemp0 = (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2) >> + * uTemp1 = (TSCLK_L + TSCLK_H + 2) >> + * uTemp2 = TSCLK_L + TSCLK_H >> + */ > > wrong indentation > > (back to my vacations now) Thanks for your time. (i was wondering if anyone would care during this vacation season.) > > -- > balbi Will post the v3, fixing all comments except the (moving to out label) one.
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index bdca511..4caea76 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -618,6 +618,13 @@ config I2C_S3C2410 Say Y here to include support for I2C controller in the Samsung SoCs. +config I2C_EXYNOS5 + tristate "Exynos5 high-speed I2C driver" + depends on ARCH_EXYNOS5 + help + Say Y here to include support for High-speed I2C controller in the + Exynos5 based Samsung SoCs. + config I2C_S6000 tristate "S6000 I2C support" depends on XTENSA_VARIANT_S6000 diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 6181f3f..4b1548c 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -61,6 +61,7 @@ obj-$(CONFIG_I2C_PUV3) += i2c-puv3.o obj-$(CONFIG_I2C_PXA) += i2c-pxa.o obj-$(CONFIG_I2C_PXA_PCI) += i2c-pxa-pci.o obj-$(CONFIG_I2C_S3C2410) += i2c-s3c2410.o +obj-$(CONFIG_I2C_EXYNOS5) += i2c-exynos5.o obj-$(CONFIG_I2C_S6000) += i2c-s6000.o obj-$(CONFIG_I2C_SH7760) += i2c-sh7760.o obj-$(CONFIG_I2C_SH_MOBILE) += i2c-sh_mobile.o diff --git a/drivers/i2c/busses/i2c-exynos5.c b/drivers/i2c/busses/i2c-exynos5.c new file mode 100644 index 0000000..7614f60 --- /dev/null +++ b/drivers/i2c/busses/i2c-exynos5.c @@ -0,0 +1,652 @@ +/* linux/drivers/i2c/busses/i2c-exynos5.c + * + * Copyright (C) 2012 Samsung Electronics Co., Ltd. + * + * High speed I2C controller driver + * for Exynos5 and later SoCs from Samsung. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. +*/ + +#include <linux/kernel.h> +#include <linux/module.h> + +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/time.h> +#include <linux/interrupt.h> +#include <linux/delay.h> +#include <linux/errno.h> +#include <linux/err.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/clk.h> +#include <linux/slab.h> +#include <linux/io.h> +#include <linux/of_address.h> +#include <linux/of_gpio.h> +#include <linux/of_irq.h> +#include <linux/of_i2c.h> + +#include "i2c-exynos5.h" + +#define EXYNOS5_I2C_TIMEOUT (msecs_to_jiffies(1000)) + +/* timeout for pm runtime autosuspend */ +#define EXYNOS5_I2C_PM_TIMEOUT 1000 /* ms */ + +struct exynos5_i2c { + struct i2c_adapter adap; + unsigned int suspended:1; + + struct i2c_msg *msg; + unsigned int msg_idx; + struct completion msg_complete; + unsigned int msg_ptr; + + unsigned int irq; + + void __iomem *regs; + struct clk *clk; + struct device *dev; + int gpios[2]; + + int bus_num; + int speed_mode; +}; + +static const struct of_device_id exynos5_i2c_match[] = { + { .compatible = "samsung,exynos5-hsi2c" }, + {}, +}; +MODULE_DEVICE_TABLE(of, exynos5_i2c_match); + +/* TODO: Should go to debugfs */ +static inline void dump_i2c_register(struct exynos5_i2c *i2c) +{ + dev_vdbg(i2c->dev, "Register dump(%d) :\n %x\n %x\n %x\n %x\n" + " %x\n %x\n %x\n %x\n %x\n" + " %x\n %x\n %x\n %x\n %x\n" + " %x\n %x\n %x\n %x\n %x\n" + " %x\n %x\n %x\n %x\n %x\n", + i2c->suspended, + readl(i2c->regs + HSI2C_CTL), + readl(i2c->regs + HSI2C_FIFO_CTL), + readl(i2c->regs + HSI2C_TRAILIG_CTL), + readl(i2c->regs + HSI2C_CLK_CTL), + readl(i2c->regs + HSI2C_CLK_SLOT), + readl(i2c->regs + HSI2C_INT_ENABLE), + readl(i2c->regs + HSI2C_INT_STATUS), + readl(i2c->regs + HSI2C_ERR_STATUS), + readl(i2c->regs + HSI2C_FIFO_STATUS), + readl(i2c->regs + HSI2C_TX_DATA), + readl(i2c->regs + HSI2C_RX_DATA), + readl(i2c->regs + HSI2C_CONF), + readl(i2c->regs + HSI2C_AUTO_CONF), + readl(i2c->regs + HSI2C_TIMEOUT), + readl(i2c->regs + HSI2C_MANUAL_CMD), + readl(i2c->regs + HSI2C_TRANS_STATUS), + readl(i2c->regs + HSI2C_TIMING_HS1), + readl(i2c->regs + HSI2C_TIMING_HS2), + readl(i2c->regs + HSI2C_TIMING_HS3), + readl(i2c->regs + HSI2C_TIMING_FS1), + readl(i2c->regs + HSI2C_TIMING_FS2), + readl(i2c->regs + HSI2C_TIMING_FS3), + readl(i2c->regs + HSI2C_TIMING_SLA), + readl(i2c->regs + HSI2C_ADDR)); +} + +static inline void exynos5_i2c_stop(struct exynos5_i2c *i2c, int ret) +{ + dev_dbg(i2c->dev, "STOP\n"); + + i2c->msg_idx++; + if (ret) + i2c->msg_idx = ret; + + /* Disable interrrupts */ + writel(0, i2c->regs + HSI2C_INT_ENABLE); + complete(&i2c->msg_complete); +} + +static void exynos5_i2c_en_timeout(struct exynos5_i2c *i2c) +{ + unsigned long i2c_timeout = readl(i2c->regs + HSI2C_TIMEOUT); + + /* Clear to enable Timeout */ + i2c_timeout &= ~HSI2C_TIMEOUT_EN; + writel(i2c_timeout, i2c->regs + HSI2C_TIMEOUT); +} + +static void exynos5_i2c_master_run(struct exynos5_i2c *i2c) +{ + /* Start data transfer in Master mode */ + u32 i2c_auto_conf = readl(i2c->regs + HSI2C_AUTO_CONF); + i2c_auto_conf |= HSI2C_MASTER_RUN; + writel(i2c_auto_conf, i2c->regs + HSI2C_AUTO_CONF); +} + +/* exynos5_i2c_set_bus + * + * get the i2c bus for a master/slave transaction + */ +static int exynos5_i2c_set_bus(struct exynos5_i2c *i2c, int master) +{ + unsigned long t_status; + int timeout = 400; + + while (timeout-- > 0) { + t_status = readl(i2c->regs + HSI2C_TRANS_STATUS); + + if (master) { + if (!(t_status & HSI2C_MASTER_BUSY)) + return 0; + } else { + if (!(t_status & HSI2C_SLAVE_BUSY)) + return 0; + } + + msleep(20); + } + + return -ETIMEDOUT; +} + +/* exynos5_i2c_irq + * + * top level IRQ servicing routine + */ +static irqreturn_t exynos5_i2c_irq(int irqno, void *dev_id) +{ + struct exynos5_i2c *i2c = dev_id; + unsigned long t_stat; + unsigned char byte; + + t_stat = readl(i2c->regs + HSI2C_TRANS_STATUS); + + if (t_stat & HSI2C_TRANS_ABORT) { + /* deal with arbitration loss */ + dev_err(i2c->dev, "deal with arbitration loss\n"); + goto out; + } + if (i2c->msg->flags & I2C_M_RD) { + if (t_stat & HSI2C_TRANS_DONE) { + dev_dbg(i2c->dev, "Device found."); + while ((readl(i2c->regs + HSI2C_FIFO_STATUS) & + HSI2C_RX_FIFO_EMPTY) == 0) { + byte = readl(i2c->regs + HSI2C_RX_DATA); + dev_dbg(i2c->dev, "read rx_data = %x", byte); + i2c->msg->buf[i2c->msg_ptr++] = byte; + } + } else if (t_stat & HSI2C_NO_DEV) { + dev_dbg(i2c->dev, "No device found."); + exynos5_i2c_stop(i2c, -ENXIO); + } else if (t_stat & HSI2C_NO_DEV_ACK && + !(i2c->msg->flags & I2C_M_IGNORE_NAK)) { + dev_dbg(i2c->dev, "No device Ack."); + exynos5_i2c_stop(i2c, -ENXIO); + } + } else { + byte = i2c->msg->buf[i2c->msg_ptr++]; + dev_dbg(i2c->dev, "write tx_data = %x ", byte); + writel(byte, i2c->regs + HSI2C_TX_DATA); + } + + if (i2c->msg_ptr >= i2c->msg->len) + exynos5_i2c_stop(i2c, 0); + + out: + /* Set those bits to clear them */ + writel(readl(i2c->regs + HSI2C_INT_STATUS), + i2c->regs + HSI2C_INT_STATUS); + + return IRQ_HANDLED; +} + +static void exynos5_i2c_message_start(struct exynos5_i2c *i2c, + struct i2c_msg *msgs) +{ + unsigned long usi_ctl = HSI2C_FUNC_MODE_I2C | HSI2C_MASTER; + unsigned long i2c_auto_conf; + unsigned long i2c_addr = ((msgs->addr & 0x7f) << 10); + unsigned long usi_int_en = 0; + + exynos5_i2c_en_timeout(i2c); + + if (msgs->flags & I2C_M_RD) { + usi_ctl &= ~HSI2C_TXCHON; + usi_ctl |= HSI2C_RXCHON; + + i2c_auto_conf |= HSI2C_READ_WRITE; + + usi_int_en |= (HSI2C_INT_RX_ALMOSTFULL_EN | + HSI2C_INT_TRAILING_EN); + } else { + usi_ctl &= ~HSI2C_RXCHON; + usi_ctl |= HSI2C_TXCHON; + + i2c_auto_conf &= ~HSI2C_READ_WRITE; + + usi_int_en |= HSI2C_INT_TX_ALMOSTEMPTY_EN; + } + + writel(i2c_addr, i2c->regs + HSI2C_ADDR); + writel(usi_ctl, i2c->regs + HSI2C_CTL); + + i2c_auto_conf |= i2c->msg->len; + i2c_auto_conf |= HSI2C_STOP_AFTER_TRANS; + writel(i2c_auto_conf, i2c->regs + HSI2C_AUTO_CONF); + + exynos5_i2c_master_run(i2c); + + /* Enable appropriate interrupts */ + writel(usi_int_en, i2c->regs + HSI2C_INT_ENABLE); +} + +static int exynos5_i2c_doxfer(struct exynos5_i2c *i2c, struct i2c_msg *msgs) +{ + unsigned long timeout; + + if (i2c->suspended) { + dev_err(i2c->dev, "HS-I2C is not initialzed.\n"); + return -EIO; + } + + if (exynos5_i2c_set_bus(i2c, 1)) { + dev_err(i2c->dev, "cannot get bus, Master busy.\n"); + return -EAGAIN; + } + + i2c->msg = msgs; + i2c->msg_ptr = 0; + i2c->msg_idx = 0; + + INIT_COMPLETION(i2c->msg_complete); + + exynos5_i2c_message_start(i2c, msgs); + + timeout = wait_for_completion_timeout(&i2c->msg_complete, + EXYNOS5_I2C_TIMEOUT); + + if (timeout == 0) + dev_dbg(i2c->dev, "timeout\n"); + else if (i2c->msg_idx != msgs->len) + dev_dbg(i2c->dev, "incomplete xfer (%d)\n", i2c->msg_idx); + + return i2c->msg_idx; +} + +static int exynos5_i2c_xfer(struct i2c_adapter *adap, + struct i2c_msg *msgs, int num) +{ + struct exynos5_i2c *i2c = (struct exynos5_i2c *)adap->algo_data; + int retry, i; + int ret; + + ret = pm_runtime_get_sync(i2c->dev); + if (IS_ERR_VALUE(ret)) + goto out; + + clk_prepare_enable(i2c->clk); + + for (retry = 0; retry < adap->retries; retry++) { + for (i = 0; i < num; i++) { + ret = exynos5_i2c_doxfer(i2c, msgs); + msgs++; + + if (ret == -EAGAIN) + break; + } + if (i == num) { + clk_disable_unprepare(i2c->clk); + ret = i2c->msg_idx; + goto out; + } + + dev_dbg(i2c->dev, "retrying transfer (%d)\n", retry); + + udelay(100); + } + + ret = -EREMOTEIO; + clk_disable_unprepare(i2c->clk); + out: + pm_runtime_mark_last_busy(i2c->dev); + pm_runtime_put_autosuspend(i2c->dev); + return ret; +} + +static u32 exynos5_i2c_func(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; +} + +static const struct i2c_algorithm exynos5_i2c_algorithm = { + .master_xfer = exynos5_i2c_xfer, + .functionality = exynos5_i2c_func, +}; + +static int exynos5_i2c_set_timing(struct exynos5_i2c *i2c, int speed_mode) +{ + unsigned long i2c_timing_s1; + unsigned long i2c_timing_s2; + unsigned long i2c_timing_s3; + unsigned long i2c_timing_sla; + unsigned int op_clk; + unsigned int clkin = clk_get_rate(i2c->clk); + unsigned int n_clkdiv; + unsigned int t_start_su, t_start_hd; + unsigned int t_stop_su; + unsigned int t_data_su, t_data_hd; + unsigned int t_scl_l, t_scl_h; + unsigned int t_sr_release; + unsigned int t_ftl_cycle; + unsigned int i = 0, utemp0 = 0, utemp1 = 0, utemp2 = 0; + + if (speed_mode == HSI2C_HIGH_SPD) + op_clk = HSI2C_HS_TX_CLOCK; + else + op_clk = HSI2C_FS_TX_CLOCK; + + /* FPCLK / FI2C = + * (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2) + 8 + 2 * FLT_CYCLE + * uTemp0 = (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2) + * uTemp1 = (TSCLK_L + TSCLK_H + 2) + * uTemp2 = TSCLK_L + TSCLK_H + */ + t_ftl_cycle = (readl(i2c->regs + HSI2C_CONF) >> 16) & 0x7; + utemp0 = (clkin / op_clk) - 8 - 2 * t_ftl_cycle; + + /* CLK_DIV max is 256 */ + for (i = 0; i < 256; i++) { + utemp1 = utemp0 / (i + 1); + /* SCLK_L/H max is 255 + * so sclk_l + sclk_h has max value of 510 + */ + if (utemp1 < 511) { + utemp2 = utemp1 - 2; + break; + } + } + + n_clkdiv = i; + t_scl_l = utemp2 / 2; + t_scl_h = utemp2 / 2; + t_start_su = t_scl_l; + t_start_hd = t_scl_l; + t_stop_su = t_scl_l; + t_data_su = t_scl_l / 2; + t_data_hd = t_scl_l / 2; + t_sr_release = utemp2; + + i2c_timing_s1 = t_start_su << 24 | t_start_hd << 16 | t_stop_su << 8; + i2c_timing_s2 = t_data_su << 24 | t_scl_l << 8 | t_scl_h << 0; + i2c_timing_s3 = n_clkdiv << 16 | t_sr_release << 0; + i2c_timing_sla = t_data_hd << 0; + + dev_dbg(i2c->dev, "tSTART_SU: %X, tSTART_HD: %X, tSTOP_SU: %X\n", + t_start_su, t_start_hd, t_stop_su); + dev_dbg(i2c->dev, "tDATA_SU: %X, tSCL_L: %X, tSCL_H: %X\n", + t_data_su, t_scl_l, t_scl_h); + dev_dbg(i2c->dev, "nClkDiv: %X, tSR_RELEASE: %X\n", + n_clkdiv, t_sr_release); + dev_dbg(i2c->dev, "tDATA_HD: %X\n", t_data_hd); + + if (speed_mode == HSI2C_HIGH_SPD) { + writel(i2c_timing_s1, i2c->regs + HSI2C_TIMING_HS1); + writel(i2c_timing_s2, i2c->regs + HSI2C_TIMING_HS2); + writel(i2c_timing_s3, i2c->regs + HSI2C_TIMING_HS3); + } else { + writel(i2c_timing_s1, i2c->regs + HSI2C_TIMING_FS1); + writel(i2c_timing_s2, i2c->regs + HSI2C_TIMING_FS2); + writel(i2c_timing_s3, i2c->regs + HSI2C_TIMING_FS3); + } + writel(i2c_timing_sla, i2c->regs + HSI2C_TIMING_SLA); + + return 0; +} + +/** + * Parse a list of GPIOs from a node property and request each one + * + * @param i2c i2c driver data + * @return 0 on success, -ve on error, in which case no GPIOs requested + */ +static int exynos5_i2c_parse_dt_gpio(struct exynos5_i2c *i2c) +{ + int idx, gpio, ret; + + for (idx = 0; idx < 2; idx++) { + gpio = of_get_gpio(i2c->dev->of_node, idx); + if (!gpio_is_valid(gpio)) { + dev_err(i2c->dev, "invalid gpio[%d]: %d\n", idx, gpio); + return -EINVAL; + } + i2c->gpios[idx] = gpio; + + ret = devm_gpio_request(i2c->dev, gpio, "i2c-bus"); + if (ret) { + dev_err(i2c->dev, "gpio [%d] request failed\n", gpio); + return -EINVAL; + } + } + return 0; +} + +static void exynos5_i2c_init(struct exynos5_i2c *i2c) +{ + unsigned long usi_trailing_ctl = HSI2C_TRAILING_COUNT; + unsigned long i2c_conf = HSI2C_AUTO_MODE; + unsigned long usi_fifo_ctl; + + writel(usi_trailing_ctl, i2c->regs + HSI2C_TRAILIG_CTL); + + /* Set default trigger level for TXFIFO and RXFIFO */ + usi_fifo_ctl = HSI2C_TXFIFO_TRIGGER_LEVEL | HSI2C_RXFIFO_TRIGGER_LEVEL; + + /* Enable RXFIFO and TXFIFO */ + usi_fifo_ctl = HSI2C_RXFIFO_EN | HSI2C_TXFIFO_EN; + writel(usi_fifo_ctl, i2c->regs + HSI2C_FIFO_CTL); + + if (i2c->speed_mode == HSI2C_HIGH_SPD) { + exynos5_i2c_set_timing(i2c, HSI2C_HIGH_SPD); + /* Configure I2C controller in High speed mode */ + i2c_conf |= HSI2C_HS_MODE; + writel(i2c_conf, i2c->regs + HSI2C_CONF); + } else { + /* Configure I2C controller in Fast speed mode */ + exynos5_i2c_set_timing(i2c, HSI2C_FAST_SPD); + } +} + +static int exynos5_i2c_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct exynos5_i2c *i2c; + int ret; + + if (!np) { + dev_err(&pdev->dev, "no device node\n"); + return -ENOENT; + } + + i2c = devm_kzalloc(&pdev->dev, sizeof(struct exynos5_i2c), GFP_KERNEL); + if (!i2c) { + dev_err(&pdev->dev, "no memory for state\n"); + return -ENOMEM; + } + + i2c->bus_num = -1; + /* Mode of operation High/Fast Speed mode */ + of_property_read_u32(np, "samsung,hs-mode", &i2c->speed_mode); + + strlcpy(i2c->adap.name, "exynos5-hsi2c", sizeof(i2c->adap.name)); + i2c->adap.owner = THIS_MODULE; + i2c->adap.algo = &exynos5_i2c_algorithm; + i2c->adap.retries = 2; + i2c->adap.class = I2C_CLASS_HWMON | I2C_CLASS_SPD; + + i2c->dev = &pdev->dev; + i2c->clk = clk_get(&pdev->dev, "hsi2c"); + if (IS_ERR(i2c->clk)) { + dev_err(&pdev->dev, "cannot get clock\n"); + ret = -ENOENT; + goto err_noclk; + } + + dev_dbg(&pdev->dev, "clock source %p\n", i2c->clk); + + clk_prepare_enable(i2c->clk); + + i2c->regs = of_iomap(np, 0); + if (!i2c->regs) { + dev_err(&pdev->dev, "cannot map HS-I2C IO\n"); + ret = -ENXIO; + goto err_clk; + } + + /* inititalise the gpio */ + if (exynos5_i2c_parse_dt_gpio(i2c)) + return -EINVAL; + + i2c->irq = irq_of_parse_and_map(np, 0); + if (i2c->irq) { + ret = devm_request_irq(&pdev->dev, i2c->irq, exynos5_i2c_irq, + 0, dev_name(&pdev->dev), i2c); + if (ret < 0) { + dev_err(&pdev->dev, "cannot request HS-I2C IRQ %d\n", + i2c->irq); + goto err_iomap; + } + } + + /* TODO: Use private lock to avoid race conditions as + * mentioned in pm_runtime.txt + */ + pm_runtime_enable(i2c->dev); + pm_runtime_set_autosuspend_delay(i2c->dev, EXYNOS5_I2C_PM_TIMEOUT); + pm_runtime_use_autosuspend(i2c->dev); + + ret = pm_runtime_get_sync(i2c->dev); + if (IS_ERR_VALUE(ret)) + goto err_iomap; + + exynos5_i2c_init(i2c); + + i2c->adap.algo_data = i2c; + i2c->adap.dev.parent = &pdev->dev; + i2c->adap.nr = i2c->bus_num; + i2c->adap.dev.of_node = pdev->dev.of_node; + + ret = i2c_add_numbered_adapter(&i2c->adap); + if (ret < 0) { + dev_err(&pdev->dev, "failed to add bus to i2c core\n"); + goto err_pm; + } + + init_completion(&i2c->msg_complete); + of_i2c_register_devices(&i2c->adap); + platform_set_drvdata(pdev, i2c); + + dev_info(&pdev->dev, "%s: Exynos5 HS-I2C adapter\n", + dev_name(&i2c->adap.dev)); + + clk_disable_unprepare(i2c->clk); + pm_runtime_mark_last_busy(i2c->dev); + pm_runtime_put_autosuspend(i2c->dev); + return 0; + + err_pm: + pm_runtime_put(i2c->dev); + pm_runtime_disable(&pdev->dev); + err_iomap: + iounmap(i2c->regs); + err_clk: + clk_disable_unprepare(i2c->clk); + err_noclk: + return ret; +} + +static int exynos5_i2c_remove(struct platform_device *pdev) +{ + struct exynos5_i2c *i2c = platform_get_drvdata(pdev); + int ret; + + ret = pm_runtime_get_sync(&pdev->dev); + if (IS_ERR_VALUE(ret)) + return ret; + + clk_disable_unprepare(i2c->clk); + pm_runtime_put(&pdev->dev); + pm_runtime_disable(&pdev->dev); + + i2c_del_adapter(&i2c->adap); + + iounmap(i2c->regs); + platform_set_drvdata(pdev, NULL); + + return 0; +} + +#ifdef CONFIG_PM +static int exynos5_i2c_suspend_noirq(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct exynos5_i2c *i2c = platform_get_drvdata(pdev); + + i2c->suspended = 1; + + return 0; +} + +static int exynos5_i2c_resume_noirq(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct exynos5_i2c *i2c = platform_get_drvdata(pdev); + + clk_prepare_enable(i2c->clk); + exynos5_i2c_init(i2c); + clk_disable_unprepare(i2c->clk); + i2c->suspended = 0; + + return 0; +} + +static const struct dev_pm_ops exynos5_i2c_dev_pm_ops = { + .suspend_noirq = exynos5_i2c_suspend_noirq, + .resume_noirq = exynos5_i2c_resume_noirq, +}; + +#define EXYNOS5_DEV_PM_OPS (&exynos5_i2c_dev_pm_ops) +#else +#define EXYNOS5_DEV_PM_OPS NULL +#endif + +static struct platform_driver exynos5_i2c_driver = { + .probe = exynos5_i2c_probe, + .remove = exynos5_i2c_remove, + .driver = { + .owner = THIS_MODULE, + .name = "exynos5-hsi2c", + .pm = EXYNOS5_DEV_PM_OPS, + .of_match_table = exynos5_i2c_match, + }, +}; + +static int __init i2c_adap_exynos5_init(void) +{ + return platform_driver_register(&exynos5_i2c_driver); +} +subsys_initcall(i2c_adap_exynos5_init); + +static void __exit i2c_adap_exynos5_exit(void) +{ + platform_driver_unregister(&exynos5_i2c_driver); +} +module_exit(i2c_adap_exynos5_exit); + +MODULE_DESCRIPTION("Exynos5 HS-I2C Bus driver"); +MODULE_AUTHOR("Taekgyun Ko, <taeggyun.ko@samsung.com>"); +MODULE_LICENSE("GPL"); diff --git a/drivers/i2c/busses/i2c-exynos5.h b/drivers/i2c/busses/i2c-exynos5.h new file mode 100644 index 0000000..4adcf88 --- /dev/null +++ b/drivers/i2c/busses/i2c-exynos5.h @@ -0,0 +1,102 @@ +/* + * Copyright (C) 2012 Samsung Electronics Co., Ltd. + * + * Exynos5 series High Speed I2C Controller + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. +*/ + +#ifndef __ASM_ARCH_REGS_HS_IIC_H +#define __ASM_ARCH_REGS_HS_IIC_H + +/* Register Map */ +#define HSI2C_CTL 0x00 +#define HSI2C_FIFO_CTL 0x04 +#define HSI2C_TRAILIG_CTL 0x08 +#define HSI2C_CLK_CTL 0x0C +#define HSI2C_CLK_SLOT 0x10 +#define HSI2C_INT_ENABLE 0x20 +#define HSI2C_INT_STATUS 0x24 +#define HSI2C_ERR_STATUS 0x2C +#define HSI2C_FIFO_STATUS 0x30 +#define HSI2C_TX_DATA 0x34 +#define HSI2C_RX_DATA 0x38 +#define HSI2C_CONF 0x40 +#define HSI2C_AUTO_CONF 0x44 +#define HSI2C_TIMEOUT 0x48 +#define HSI2C_MANUAL_CMD 0x4C +#define HSI2C_TRANS_STATUS 0x50 +#define HSI2C_TIMING_HS1 0x54 +#define HSI2C_TIMING_HS2 0x58 +#define HSI2C_TIMING_HS3 0x5C +#define HSI2C_TIMING_FS1 0x60 +#define HSI2C_TIMING_FS2 0x64 +#define HSI2C_TIMING_FS3 0x68 +#define HSI2C_TIMING_SLA 0x6C +#define HSI2C_ADDR 0x70 + +/* I2C_CTL Register */ +#define HSI2C_FUNC_MODE_I2C (1u << 0) +#define HSI2C_MASTER (1u << 3) +#define HSI2C_RXCHON (1u << 6) +#define HSI2C_TXCHON (1u << 7) +#define HSI2C_SW_RST (1u << 31) + +/* I2C_FIFO_CTL Register */ +#define HSI2C_RXFIFO_EN (1u << 0) +#define HSI2C_TXFIFO_EN (1u << 1) +#define HSI2C_TXFIFO_TRIGGER_LEVEL (0x20 << 16) +#define HSI2C_RXFIFO_TRIGGER_LEVEL (0x20 << 4) + +/* I2C_TRAILING_CTL Register */ +#define HSI2C_TRAILING_COUNT (0xf) + +/* I2C_INT_EN Register */ +#define HSI2C_INT_TX_ALMOSTEMPTY_EN (1u << 0) +#define HSI2C_INT_RX_ALMOSTFULL_EN (1u << 1) +#define HSI2C_INT_TRAILING_EN (1u << 6) +#define HSI2C_INT_I2C_EN (1u << 9) + +/* I2C_FIFO_STAT Register */ +#define HSI2C_RX_FIFO_EMPTY (1u << 24) +#define HSI2C_RX_FIFO_FULL (1u << 23) +#define HSI2C_RX_FIFO_LEVEL_MASK (0x7 << 16) +#define HSI2C_TX_FIFO_EMPTY (1u << 8) +#define HSI2C_TX_FIFO_FULL (1u << 7) +#define HSI2C_TX_FIFO_LEVEL_MASK (0x7 << 7) +#define HSI2C_FIFO_EMPTY (0x1000100) + +/* I2C_CONF Register */ +#define HSI2C_AUTO_MODE (1u << 31) +#define HSI2C_10BIT_ADDR_MODE (1u << 30) +#define HSI2C_HS_MODE (1u << 29) + +/* I2C_AUTO_CONF Register */ +#define HSI2C_READ_WRITE (1u << 16) +#define HSI2C_STOP_AFTER_TRANS (1u << 17) +#define HSI2C_MASTER_RUN (1u << 31) + +/* I2C_TIMEOUT Register */ +#define HSI2C_TIMEOUT_EN (1u << 31) + +/* I2C_TRANS_STATUS register */ +#define HSI2C_MASTER_BUSY (1u << 17) +#define HSI2C_SLAVE_BUSY (1u << 16) +#define HSI2C_NO_DEV (1u << 3) +#define HSI2C_NO_DEV_ACK (1u << 2) +#define HSI2C_TRANS_ABORT (1u << 1) +#define HSI2C_TRANS_DONE (1u << 0) + +/* Although exynos5 supports max HS-IIC speed of 3.4Mhz, + * but currently we are facing booting issues beyond 1Mhz + * So limiting HS-IIC bus speed to 1Mhz + */ +#define HSI2C_HS_TX_CLOCK 1000000 +#define HSI2C_FS_TX_CLOCK 400000 + +#define HSI2C_FAST_SPD 0 +#define HSI2C_HIGH_SPD 1 + +#endif /* __ASM_ARCH_REGS_HS_IIC_H */