| Message ID | 20191007231313.4700-5-jae.hyun.yoo@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | i2c: aspeed: Add buffer and DMA modes support | expand |
On Mon, Oct 07, 2019 at 04:13:12PM -0700, Jae Hyun Yoo wrote: > Byte mode currently this driver uses makes lots of interrupt call nit: Drop "Byte mode". > which isn't good for performance and it makes the driver very > timing sensitive. To improve performance of the driver, this commit > adds buffer mode transfer support which uses I2C SRAM buffer > instead of using a single byte buffer. nit: Please use imperative mood. > Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com> > Tested-by: Tao Ren <taoren@fb.com> > --- > drivers/i2c/busses/i2c-aspeed.c | 297 ++++++++++++++++++++++++++++---- > 1 file changed, 263 insertions(+), 34 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c > index 40f6cf98d32e..37d1a7fa2f87 100644 > --- a/drivers/i2c/busses/i2c-aspeed.c > +++ b/drivers/i2c/busses/i2c-aspeed.c > @@ -7,6 +7,7 @@ > * Copyright 2017 Google, Inc. > */ > > +#include <linux/bitfield.h> > #include <linux/clk.h> > #include <linux/completion.h> > #include <linux/err.h> > @@ -19,15 +20,24 @@ > #include <linux/irqchip/chained_irq.h> > #include <linux/irqdomain.h> > #include <linux/kernel.h> > +#include <linux/mfd/syscon.h> > #include <linux/module.h> > #include <linux/of_address.h> > #include <linux/of_irq.h> > #include <linux/of_platform.h> > #include <linux/platform_device.h> > +#include <linux/regmap.h> > #include <linux/reset.h> > #include <linux/slab.h> > > -/* I2C Register */ > +/* I2C Global Registers */ > +/* 0x00 : I2CG Interrupt Status Register */ > +/* 0x08 : I2CG Interrupt Target Assignment */ > +/* 0x0c : I2CG Global Control Register (AST2500) */ > +#define ASPEED_I2CG_GLOBAL_CTRL_REG 0x0c > +#define ASPEED_I2CG_SRAM_BUFFER_EN BIT(0) > + > +/* I2C Bus Registers */ > #define ASPEED_I2C_FUN_CTRL_REG 0x00 > #define ASPEED_I2C_AC_TIMING_REG1 0x04 > #define ASPEED_I2C_AC_TIMING_REG2 0x08 > @@ -35,14 +45,12 @@ > #define ASPEED_I2C_INTR_STS_REG 0x10 > #define ASPEED_I2C_CMD_REG 0x14 > #define ASPEED_I2C_DEV_ADDR_REG 0x18 > +#define ASPEED_I2C_BUF_CTRL_REG 0x1c > #define ASPEED_I2C_BYTE_BUF_REG 0x20 > > -/* Global Register Definition */ > -/* 0x00 : I2C Interrupt Status Register */ > -/* 0x08 : I2C Interrupt Target Assignment */ > - > /* Device Register Definition */ > /* 0x00 : I2CD Function Control Register */ > +#define ASPEED_I2CD_BUFFER_PAGE_SEL_MASK GENMASK(22, 20) > #define ASPEED_I2CD_MULTI_MASTER_DIS BIT(15) > #define ASPEED_I2CD_SDA_DRIVE_1T_EN BIT(8) > #define ASPEED_I2CD_M_SDA_DRIVE_1T_EN BIT(7) > @@ -102,6 +110,8 @@ > #define ASPEED_I2CD_BUS_RECOVER_CMD BIT(11) > > /* Command Bit */ > +#define ASPEED_I2CD_RX_BUFF_ENABLE BIT(7) > +#define ASPEED_I2CD_TX_BUFF_ENABLE BIT(6) > #define ASPEED_I2CD_M_STOP_CMD BIT(5) > #define ASPEED_I2CD_M_S_RX_CMD_LAST BIT(4) > #define ASPEED_I2CD_M_RX_CMD BIT(3) > @@ -112,6 +122,13 @@ > /* 0x18 : I2CD Slave Device Address Register */ > #define ASPEED_I2CD_DEV_ADDR_MASK GENMASK(6, 0) > > +/* 0x1c : I2CD Buffer Control Register */ > +/* Use 8-bits or 6-bits wide bit fileds to support both AST2400 and AST2500 */ > +#define ASPEED_I2CD_BUF_RX_COUNT_MASK GENMASK(31, 24) > +#define ASPEED_I2CD_BUF_RX_SIZE_MASK GENMASK(23, 16) > +#define ASPEED_I2CD_BUF_TX_COUNT_MASK GENMASK(15, 8) > +#define ASPEED_I2CD_BUF_OFFSET_MASK GENMASK(5, 0) > + > enum aspeed_i2c_master_state { > ASPEED_I2C_MASTER_INACTIVE, > ASPEED_I2C_MASTER_PENDING, > @@ -157,6 +174,11 @@ struct aspeed_i2c_bus { > int master_xfer_result; > /* Multi-master */ > bool multi_master; > + /* Buffer mode */ > + void __iomem *buf_base; > + size_t buf_size; > + u8 buf_offset; > + u8 buf_page; > #if IS_ENABLED(CONFIG_I2C_SLAVE) > struct i2c_client *slave; > enum aspeed_i2c_slave_state slave_state; > @@ -238,6 +260,7 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) > { > u32 command, irq_handled = 0; > struct i2c_client *slave = bus->slave; > + int i, len; > u8 value; > > if (!slave) > @@ -260,7 +283,12 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) > > /* Slave was sent something. */ > if (irq_status & ASPEED_I2CD_INTR_RX_DONE) { > - value = readl(bus->base + ASPEED_I2C_BYTE_BUF_REG) >> 8; > + if (bus->buf_base && > + bus->slave_state == ASPEED_I2C_SLAVE_WRITE_RECEIVED && > + !(irq_status & ASPEED_I2CD_INTR_NORMAL_STOP)) I think checking for the buf_base all over the place makes this really complicated and hard to read. It might be better to just split this out and have separate handlers based on what mode the driver is running in. > + value = readb(bus->buf_base); > + else > + value = readl(bus->base + ASPEED_I2C_BYTE_BUF_REG) >> 8; > /* Handle address frame. */ > if (bus->slave_state == ASPEED_I2C_SLAVE_START) { > if (value & 0x1) > @@ -275,6 +303,20 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) > > /* Slave was asked to stop. */ > if (irq_status & ASPEED_I2CD_INTR_NORMAL_STOP) { > + if (bus->slave_state == ASPEED_I2C_SLAVE_WRITE_RECEIVED && > + irq_status & ASPEED_I2CD_INTR_RX_DONE) { > + if (bus->buf_base) { > + len = FIELD_GET(ASPEED_I2CD_BUF_RX_COUNT_MASK, > + readl(bus->base + > + ASPEED_I2C_BUF_CTRL_REG)); It looks like you have a lot of improvements in here unrelated to adding support for buffer mode. I really appreciate the improvements, but it makes it harder to understand what buffer features you are adding vs. what improvments/modernizations you are making. Can you split this commit up? > + for (i = 0; i < len; i++) { > + value = readb(bus->buf_base + i); > + i2c_slave_event(slave, > + I2C_SLAVE_WRITE_RECEIVED, > + &value); > + } > + } > + } > irq_handled |= ASPEED_I2CD_INTR_NORMAL_STOP; > bus->slave_state = ASPEED_I2C_SLAVE_STOP; > } > @@ -307,9 +349,36 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) > case ASPEED_I2C_SLAVE_WRITE_REQUESTED: > bus->slave_state = ASPEED_I2C_SLAVE_WRITE_RECEIVED; > i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value); > + if (bus->buf_base) { > + writel(FIELD_PREP(ASPEED_I2CD_BUF_RX_SIZE_MASK, > + bus->buf_size - 1) | > + FIELD_PREP(ASPEED_I2CD_BUF_OFFSET_MASK, > + bus->buf_offset), > + bus->base + ASPEED_I2C_BUF_CTRL_REG); > + writel(ASPEED_I2CD_RX_BUFF_ENABLE, > + bus->base + ASPEED_I2C_CMD_REG); > + } > break; > case ASPEED_I2C_SLAVE_WRITE_RECEIVED: > i2c_slave_event(slave, I2C_SLAVE_WRITE_RECEIVED, &value); > + if (bus->buf_base) { > + len = FIELD_GET(ASPEED_I2CD_BUF_RX_COUNT_MASK, > + readl(bus->base + > + ASPEED_I2C_BUF_CTRL_REG)); > + for (i = 1; i < len; i++) { > + value = readb(bus->buf_base + i); > + i2c_slave_event(slave, > + I2C_SLAVE_WRITE_RECEIVED, > + &value); > + } > + writel(FIELD_PREP(ASPEED_I2CD_BUF_RX_SIZE_MASK, > + bus->buf_size - 1) | > + FIELD_PREP(ASPEED_I2CD_BUF_OFFSET_MASK, > + bus->buf_offset), > + bus->base + ASPEED_I2C_BUF_CTRL_REG); > + writel(ASPEED_I2CD_RX_BUFF_ENABLE, > + bus->base + ASPEED_I2C_CMD_REG); > + } > break; > case ASPEED_I2C_SLAVE_STOP: > i2c_slave_event(slave, I2C_SLAVE_STOP, &value); > @@ -335,6 +404,8 @@ static void aspeed_i2c_do_start(struct aspeed_i2c_bus *bus) > u32 command = ASPEED_I2CD_M_START_CMD | ASPEED_I2CD_M_TX_CMD; > struct i2c_msg *msg = &bus->msgs[bus->msgs_index]; > u8 slave_addr = i2c_8bit_addr_from_msg(msg); > + u8 wbuf[4]; > + int len; > > #if IS_ENABLED(CONFIG_I2C_SLAVE) > /* > @@ -353,12 +424,66 @@ static void aspeed_i2c_do_start(struct aspeed_i2c_bus *bus) > > if (msg->flags & I2C_M_RD) { > command |= ASPEED_I2CD_M_RX_CMD; > - /* Need to let the hardware know to NACK after RX. */ > - if (msg->len == 1 && !(msg->flags & I2C_M_RECV_LEN)) > - command |= ASPEED_I2CD_M_S_RX_CMD_LAST; > + > + if (bus->buf_base && !(msg->flags & I2C_M_RECV_LEN)) { > + command |= ASPEED_I2CD_RX_BUFF_ENABLE; > + > + if (msg->len > bus->buf_size) { > + len = bus->buf_size; > + } else { > + len = msg->len; > + command |= ASPEED_I2CD_M_S_RX_CMD_LAST; > + } > + > + writel(FIELD_PREP(ASPEED_I2CD_BUF_RX_SIZE_MASK, > + len - 1) | > + FIELD_PREP(ASPEED_I2CD_BUF_OFFSET_MASK, > + bus->buf_offset), > + bus->base + ASPEED_I2C_BUF_CTRL_REG); > + } else { > + /* Need to let the hardware know to NACK after RX. */ > + if (msg->len == 1 && !(msg->flags & I2C_M_RECV_LEN)) > + command |= ASPEED_I2CD_M_S_RX_CMD_LAST; > + } > + } else { > + if (bus->buf_base) { > + int i; > + > + command |= ASPEED_I2CD_TX_BUFF_ENABLE; > + > + if (msg->len + 1 > bus->buf_size) > + len = bus->buf_size; > + else > + len = msg->len + 1; > + > + /* > + * Yeah, it looks clumsy but byte writings on a remapped > + * I2C SRAM cause corruptions so use this way to make > + * dword writings. > + */ > + wbuf[0] = slave_addr; > + for (i = 1; i < len; i++) { > + wbuf[i % 4] = msg->buf[i - 1]; > + if (i % 4 == 3) > + writel(*(u32 *)wbuf, > + bus->buf_base + i - 3); > + } > + if (--i % 4 != 3) > + writel(*(u32 *)wbuf, > + bus->buf_base + i - (i % 4)); > + > + bus->buf_index = len - 1; > + > + writel(FIELD_PREP(ASPEED_I2CD_BUF_TX_COUNT_MASK, > + len - 1) | > + FIELD_PREP(ASPEED_I2CD_BUF_OFFSET_MASK, > + bus->buf_offset), > + bus->base + ASPEED_I2C_BUF_CTRL_REG); > + } > } > > - writel(slave_addr, bus->base + ASPEED_I2C_BYTE_BUF_REG); > + if (!(command & ASPEED_I2CD_TX_BUFF_ENABLE)) > + writel(slave_addr, bus->base + ASPEED_I2C_BYTE_BUF_REG); > writel(command, bus->base + ASPEED_I2C_CMD_REG); > } > > @@ -398,7 +523,7 @@ static u32 aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus, u32 irq_status) > u32 irq_handled = 0, command = 0; > struct i2c_msg *msg; > u8 recv_byte; > - int ret; > + int ret, len; > > if (irq_status & ASPEED_I2CD_INTR_BUS_RECOVER_DONE) { > bus->master_state = ASPEED_I2C_MASTER_INACTIVE; > @@ -511,11 +636,43 @@ static u32 aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus, u32 irq_status) > /* fall through */ > case ASPEED_I2C_MASTER_TX_FIRST: > if (bus->buf_index < msg->len) { > + command = ASPEED_I2CD_M_TX_CMD; > + > + if (bus->buf_base) { > + u8 wbuf[4]; > + int i; > + > + command |= ASPEED_I2CD_TX_BUFF_ENABLE; > + > + if (msg->len - bus->buf_index > bus->buf_size) > + len = bus->buf_size; > + else > + len = msg->len - bus->buf_index; > + > + for (i = 0; i < len; i++) { > + wbuf[i % 4] = msg->buf[bus->buf_index > + + i]; > + if (i % 4 == 3) > + writel(*(u32 *)wbuf, > + bus->buf_base + i - 3); > + } > + if (--i % 4 != 3) > + writel(*(u32 *)wbuf, > + bus->buf_base + i - (i % 4)); > + > + bus->buf_index += len; > + > + writel(FIELD_PREP(ASPEED_I2CD_BUF_TX_COUNT_MASK, > + len - 1) | > + FIELD_PREP(ASPEED_I2CD_BUF_OFFSET_MASK, > + bus->buf_offset), > + bus->base + ASPEED_I2C_BUF_CTRL_REG); > + } else { > + writel(msg->buf[bus->buf_index++], > + bus->base + ASPEED_I2C_BYTE_BUF_REG); > + } > + writel(command, bus->base + ASPEED_I2C_CMD_REG); > bus->master_state = ASPEED_I2C_MASTER_TX; > - writel(msg->buf[bus->buf_index++], > - bus->base + ASPEED_I2C_BYTE_BUF_REG); > - writel(ASPEED_I2CD_M_TX_CMD, > - bus->base + ASPEED_I2C_CMD_REG); > } else { > aspeed_i2c_next_msg_or_stop(bus); > } > @@ -532,25 +689,56 @@ static u32 aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus, u32 irq_status) > } > irq_handled |= ASPEED_I2CD_INTR_RX_DONE; > > - recv_byte = readl(bus->base + ASPEED_I2C_BYTE_BUF_REG) >> 8; > - msg->buf[bus->buf_index++] = recv_byte; > - > - if (msg->flags & I2C_M_RECV_LEN) { > - if (unlikely(recv_byte > I2C_SMBUS_BLOCK_MAX)) { > - bus->cmd_err = -EPROTO; > - aspeed_i2c_do_stop(bus); > - goto out_no_complete; > + if (bus->buf_base && !(msg->flags & I2C_M_RECV_LEN)) { > + len = FIELD_GET(ASPEED_I2CD_BUF_RX_COUNT_MASK, > + readl(bus->base + > + ASPEED_I2C_BUF_CTRL_REG)); > + memcpy_fromio(msg->buf + bus->buf_index, > + bus->buf_base, len); > + bus->buf_index += len; > + } else { > + recv_byte = readl(bus->base + ASPEED_I2C_BYTE_BUF_REG) > + >> 8; > + msg->buf[bus->buf_index++] = recv_byte; > + > + if (msg->flags & I2C_M_RECV_LEN) { > + if (unlikely(recv_byte > I2C_SMBUS_BLOCK_MAX)) { > + bus->cmd_err = -EPROTO; > + aspeed_i2c_do_stop(bus); > + goto out_no_complete; > + } > + msg->len = recv_byte + > + ((msg->flags & I2C_CLIENT_PEC) ? > + 2 : 1); > + msg->flags &= ~I2C_M_RECV_LEN; > } > - msg->len = recv_byte + > - ((msg->flags & I2C_CLIENT_PEC) ? 2 : 1); > - msg->flags &= ~I2C_M_RECV_LEN; > } > > if (bus->buf_index < msg->len) { > - bus->master_state = ASPEED_I2C_MASTER_RX; > command = ASPEED_I2CD_M_RX_CMD; > - if (bus->buf_index + 1 == msg->len) > - command |= ASPEED_I2CD_M_S_RX_CMD_LAST; > + bus->master_state = ASPEED_I2C_MASTER_RX; > + if (bus->buf_base) { > + command |= ASPEED_I2CD_RX_BUFF_ENABLE; > + > + if (msg->len - bus->buf_index > > + bus->buf_size) { > + len = bus->buf_size; > + } else { > + len = msg->len - bus->buf_index; > + command |= ASPEED_I2CD_M_S_RX_CMD_LAST; > + } > + > + writel(FIELD_PREP(ASPEED_I2CD_BUF_RX_SIZE_MASK, > + len - 1) | > + FIELD_PREP(ASPEED_I2CD_BUF_TX_COUNT_MASK, > + 0) | > + FIELD_PREP(ASPEED_I2CD_BUF_OFFSET_MASK, > + bus->buf_offset), > + bus->base + ASPEED_I2C_BUF_CTRL_REG); > + } else { > + if (bus->buf_index + 1 == msg->len) > + command |= ASPEED_I2CD_M_S_RX_CMD_LAST; > + } > writel(command, bus->base + ASPEED_I2C_CMD_REG); > } else { > aspeed_i2c_next_msg_or_stop(bus); > @@ -890,6 +1078,9 @@ static int aspeed_i2c_init(struct aspeed_i2c_bus *bus, > if (ret < 0) > return ret; > > + fun_ctrl_reg |= FIELD_PREP(ASPEED_I2CD_BUFFER_PAGE_SEL_MASK, > + bus->buf_page); > + > if (of_property_read_bool(pdev->dev.of_node, "multi-master")) > bus->multi_master = true; > else > @@ -947,16 +1138,15 @@ static int aspeed_i2c_probe_bus(struct platform_device *pdev) > { > const struct of_device_id *match; > struct aspeed_i2c_bus *bus; > + bool sram_enabled = true; > struct clk *parent_clk; > - struct resource *res; > int irq, ret; > > bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL); > if (!bus) > return -ENOMEM; > > - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > - bus->base = devm_ioremap_resource(&pdev->dev, res); > + bus->base = devm_platform_ioremap_resource(pdev, 0); > if (IS_ERR(bus->base)) > return PTR_ERR(bus->base); > > @@ -990,6 +1180,45 @@ static int aspeed_i2c_probe_bus(struct platform_device *pdev) > bus->get_clk_reg_val = (u32 (*)(struct device *, u32)) > match->data; > > + /* > + * Enable I2C SRAM in case of AST2500. > + * SRAM is enabled by default in AST2400 and AST2600. > + */ This probe function is already pretty complicated as it is. Can we move this to a helper function (especially since it only applies to the 25xx)? > + if (of_device_is_compatible(pdev->dev.of_node, > + "aspeed,ast2500-i2c-bus")) { > + struct regmap *gr_regmap = syscon_regmap_lookup_by_compatible("aspeed,ast2500-i2c-gr"); So this memory is global, right? It is shared by all the busses? If I am reading this right, then I think we need to protect so that only one bus is accessing this memory at a time. > + if (IS_ERR(gr_regmap)) > + ret = PTR_ERR(gr_regmap); > + else > + ret = regmap_update_bits(gr_regmap, > + ASPEED_I2CG_GLOBAL_CTRL_REG, > + ASPEED_I2CG_SRAM_BUFFER_EN, > + ASPEED_I2CG_SRAM_BUFFER_EN); > + > + if (ret) > + sram_enabled = false; > + } > + > + if (sram_enabled) { > + struct resource *res = platform_get_resource(pdev, > + IORESOURCE_MEM, 1); > + > + if (res && resource_size(res) >= 2) > + bus->buf_base = devm_ioremap_resource(&pdev->dev, res); > + > + if (!IS_ERR_OR_NULL(bus->buf_base)) { > + bus->buf_size = resource_size(res); > + if (of_device_is_compatible(pdev->dev.of_node, > + "aspeed,ast2400-i2c-bus")) { > + bus->buf_page = ((res->start >> 8) & > + GENMASK(3, 0)) - 8; > + bus->buf_offset = (res->start >> 2) & > + ASPEED_I2CD_BUF_OFFSET_MASK; > + } > + } > + } > + > /* Initialize the I2C adapter */ > spin_lock_init(&bus->lock); > init_completion(&bus->cmd_complete); > @@ -1026,8 +1255,8 @@ static int aspeed_i2c_probe_bus(struct platform_device *pdev) > > platform_set_drvdata(pdev, bus); > > - dev_info(bus->dev, "i2c bus %d registered, irq %d\n", > - bus->adap.nr, irq); > + dev_info(bus->dev, "i2c bus %d registered (%s mode), irq %d\n", > + bus->adap.nr, bus->buf_base ? "buffer" : "byte", irq); > > return 0; > } > -- > 2.23.0 >
Hi Brendan, On 10/8/2019 1:12 PM, Brendan Higgins wrote: > On Mon, Oct 07, 2019 at 04:13:12PM -0700, Jae Hyun Yoo wrote: >> Byte mode currently this driver uses makes lots of interrupt call > > nit: Drop "Byte mode". 'Byte mode' is one of modes which is described in the datasheet. Would it be better if I change it like below? "This driver uses byte mode that makes lots of interrupt call ..." >> which isn't good for performance and it makes the driver very >> timing sensitive. To improve performance of the driver, this commit >> adds buffer mode transfer support which uses I2C SRAM buffer >> instead of using a single byte buffer. > > nit: Please use imperative mood. I used imperative mood in commit title. The commit message is okay as it is. >> Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com> >> Tested-by: Tao Ren <taoren@fb.com> >> --- >> drivers/i2c/busses/i2c-aspeed.c | 297 ++++++++++++++++++++++++++++---- >> 1 file changed, 263 insertions(+), 34 deletions(-) >> >> diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c >> index 40f6cf98d32e..37d1a7fa2f87 100644 >> --- a/drivers/i2c/busses/i2c-aspeed.c >> +++ b/drivers/i2c/busses/i2c-aspeed.c >> @@ -7,6 +7,7 @@ >> * Copyright 2017 Google, Inc. >> */ >> >> +#include <linux/bitfield.h> >> #include <linux/clk.h> >> #include <linux/completion.h> >> #include <linux/err.h> >> @@ -19,15 +20,24 @@ >> #include <linux/irqchip/chained_irq.h> >> #include <linux/irqdomain.h> >> #include <linux/kernel.h> >> +#include <linux/mfd/syscon.h> >> #include <linux/module.h> >> #include <linux/of_address.h> >> #include <linux/of_irq.h> >> #include <linux/of_platform.h> >> #include <linux/platform_device.h> >> +#include <linux/regmap.h> >> #include <linux/reset.h> >> #include <linux/slab.h> >> >> -/* I2C Register */ >> +/* I2C Global Registers */ >> +/* 0x00 : I2CG Interrupt Status Register */ >> +/* 0x08 : I2CG Interrupt Target Assignment */ >> +/* 0x0c : I2CG Global Control Register (AST2500) */ >> +#define ASPEED_I2CG_GLOBAL_CTRL_REG 0x0c >> +#define ASPEED_I2CG_SRAM_BUFFER_EN BIT(0) >> + >> +/* I2C Bus Registers */ >> #define ASPEED_I2C_FUN_CTRL_REG 0x00 >> #define ASPEED_I2C_AC_TIMING_REG1 0x04 >> #define ASPEED_I2C_AC_TIMING_REG2 0x08 >> @@ -35,14 +45,12 @@ >> #define ASPEED_I2C_INTR_STS_REG 0x10 >> #define ASPEED_I2C_CMD_REG 0x14 >> #define ASPEED_I2C_DEV_ADDR_REG 0x18 >> +#define ASPEED_I2C_BUF_CTRL_REG 0x1c >> #define ASPEED_I2C_BYTE_BUF_REG 0x20 >> >> -/* Global Register Definition */ >> -/* 0x00 : I2C Interrupt Status Register */ >> -/* 0x08 : I2C Interrupt Target Assignment */ >> - >> /* Device Register Definition */ >> /* 0x00 : I2CD Function Control Register */ >> +#define ASPEED_I2CD_BUFFER_PAGE_SEL_MASK GENMASK(22, 20) >> #define ASPEED_I2CD_MULTI_MASTER_DIS BIT(15) >> #define ASPEED_I2CD_SDA_DRIVE_1T_EN BIT(8) >> #define ASPEED_I2CD_M_SDA_DRIVE_1T_EN BIT(7) >> @@ -102,6 +110,8 @@ >> #define ASPEED_I2CD_BUS_RECOVER_CMD BIT(11) >> >> /* Command Bit */ >> +#define ASPEED_I2CD_RX_BUFF_ENABLE BIT(7) >> +#define ASPEED_I2CD_TX_BUFF_ENABLE BIT(6) >> #define ASPEED_I2CD_M_STOP_CMD BIT(5) >> #define ASPEED_I2CD_M_S_RX_CMD_LAST BIT(4) >> #define ASPEED_I2CD_M_RX_CMD BIT(3) >> @@ -112,6 +122,13 @@ >> /* 0x18 : I2CD Slave Device Address Register */ >> #define ASPEED_I2CD_DEV_ADDR_MASK GENMASK(6, 0) >> >> +/* 0x1c : I2CD Buffer Control Register */ >> +/* Use 8-bits or 6-bits wide bit fileds to support both AST2400 and AST2500 */ >> +#define ASPEED_I2CD_BUF_RX_COUNT_MASK GENMASK(31, 24) >> +#define ASPEED_I2CD_BUF_RX_SIZE_MASK GENMASK(23, 16) >> +#define ASPEED_I2CD_BUF_TX_COUNT_MASK GENMASK(15, 8) >> +#define ASPEED_I2CD_BUF_OFFSET_MASK GENMASK(5, 0) >> + >> enum aspeed_i2c_master_state { >> ASPEED_I2C_MASTER_INACTIVE, >> ASPEED_I2C_MASTER_PENDING, >> @@ -157,6 +174,11 @@ struct aspeed_i2c_bus { >> int master_xfer_result; >> /* Multi-master */ >> bool multi_master; >> + /* Buffer mode */ >> + void __iomem *buf_base; >> + size_t buf_size; >> + u8 buf_offset; >> + u8 buf_page; >> #if IS_ENABLED(CONFIG_I2C_SLAVE) >> struct i2c_client *slave; >> enum aspeed_i2c_slave_state slave_state; >> @@ -238,6 +260,7 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) >> { >> u32 command, irq_handled = 0; >> struct i2c_client *slave = bus->slave; >> + int i, len; >> u8 value; >> >> if (!slave) >> @@ -260,7 +283,12 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) >> >> /* Slave was sent something. */ >> if (irq_status & ASPEED_I2CD_INTR_RX_DONE) { >> - value = readl(bus->base + ASPEED_I2C_BYTE_BUF_REG) >> 8; >> + if (bus->buf_base && >> + bus->slave_state == ASPEED_I2C_SLAVE_WRITE_RECEIVED && >> + !(irq_status & ASPEED_I2CD_INTR_NORMAL_STOP)) > > I think checking for the buf_base all over the place makes this really > complicated and hard to read. > > It might be better to just split this out and have separate handlers > based on what mode the driver is running in. I think you're saying about splitting this irq handler out to: aspeed_i2c_slave_byte_mode_irq() aspeed_i2c_slave_buffer_mode_irq() aspeed_i2c_slave_dma_mode_irq() Yes, I can do like that but it will bring us two bad things: 1. It makes big chunks of duplicate code because most of interrupt handling logic is the same. 2. If we are going to change something in irq routine, we need to touch all irq routines if the change is commonly used. I think, the way this patch uses is better. >> + value = readb(bus->buf_base); >> + else >> + value = readl(bus->base + ASPEED_I2C_BYTE_BUF_REG) >> 8; >> /* Handle address frame. */ >> if (bus->slave_state == ASPEED_I2C_SLAVE_START) { >> if (value & 0x1) >> @@ -275,6 +303,20 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) >> >> /* Slave was asked to stop. */ >> if (irq_status & ASPEED_I2CD_INTR_NORMAL_STOP) { >> + if (bus->slave_state == ASPEED_I2C_SLAVE_WRITE_RECEIVED && >> + irq_status & ASPEED_I2CD_INTR_RX_DONE) { >> + if (bus->buf_base) { >> + len = FIELD_GET(ASPEED_I2CD_BUF_RX_COUNT_MASK, >> + readl(bus->base + >> + ASPEED_I2C_BUF_CTRL_REG)); > > It looks like you have a lot of improvements in here unrelated to adding > support for buffer mode. > > I really appreciate the improvements, but it makes it harder to > understand what buffer features you are adding vs. what > improvments/modernizations you are making. > > Can you split this commit up? No, this isn't an improvement. This code will not be executed if transfer mode is byte mode. This is added because data handling pattern is different in buffer mode so the collected data in buffer mode should be sent when it recieves RX_DONE. >> + for (i = 0; i < len; i++) { >> + value = readb(bus->buf_base + i); >> + i2c_slave_event(slave, >> + I2C_SLAVE_WRITE_RECEIVED, >> + &value); >> + } >> + } >> + } >> irq_handled |= ASPEED_I2CD_INTR_NORMAL_STOP; >> bus->slave_state = ASPEED_I2C_SLAVE_STOP; >> } >> @@ -307,9 +349,36 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) >> case ASPEED_I2C_SLAVE_WRITE_REQUESTED: >> bus->slave_state = ASPEED_I2C_SLAVE_WRITE_RECEIVED; >> i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value); >> + if (bus->buf_base) { >> + writel(FIELD_PREP(ASPEED_I2CD_BUF_RX_SIZE_MASK, >> + bus->buf_size - 1) | >> + FIELD_PREP(ASPEED_I2CD_BUF_OFFSET_MASK, >> + bus->buf_offset), >> + bus->base + ASPEED_I2C_BUF_CTRL_REG); >> + writel(ASPEED_I2CD_RX_BUFF_ENABLE, >> + bus->base + ASPEED_I2C_CMD_REG); >> + } >> break; >> case ASPEED_I2C_SLAVE_WRITE_RECEIVED: >> i2c_slave_event(slave, I2C_SLAVE_WRITE_RECEIVED, &value); >> + if (bus->buf_base) { >> + len = FIELD_GET(ASPEED_I2CD_BUF_RX_COUNT_MASK, >> + readl(bus->base + >> + ASPEED_I2C_BUF_CTRL_REG)); >> + for (i = 1; i < len; i++) { >> + value = readb(bus->buf_base + i); >> + i2c_slave_event(slave, >> + I2C_SLAVE_WRITE_RECEIVED, >> + &value); >> + } >> + writel(FIELD_PREP(ASPEED_I2CD_BUF_RX_SIZE_MASK, >> + bus->buf_size - 1) | >> + FIELD_PREP(ASPEED_I2CD_BUF_OFFSET_MASK, >> + bus->buf_offset), >> + bus->base + ASPEED_I2C_BUF_CTRL_REG); >> + writel(ASPEED_I2CD_RX_BUFF_ENABLE, >> + bus->base + ASPEED_I2C_CMD_REG); >> + } >> break; >> case ASPEED_I2C_SLAVE_STOP: >> i2c_slave_event(slave, I2C_SLAVE_STOP, &value); >> @@ -335,6 +404,8 @@ static void aspeed_i2c_do_start(struct aspeed_i2c_bus *bus) >> u32 command = ASPEED_I2CD_M_START_CMD | ASPEED_I2CD_M_TX_CMD; >> struct i2c_msg *msg = &bus->msgs[bus->msgs_index]; >> u8 slave_addr = i2c_8bit_addr_from_msg(msg); >> + u8 wbuf[4]; >> + int len; >> >> #if IS_ENABLED(CONFIG_I2C_SLAVE) >> /* >> @@ -353,12 +424,66 @@ static void aspeed_i2c_do_start(struct aspeed_i2c_bus *bus) >> >> if (msg->flags & I2C_M_RD) { >> command |= ASPEED_I2CD_M_RX_CMD; >> - /* Need to let the hardware know to NACK after RX. */ >> - if (msg->len == 1 && !(msg->flags & I2C_M_RECV_LEN)) >> - command |= ASPEED_I2CD_M_S_RX_CMD_LAST; >> + >> + if (bus->buf_base && !(msg->flags & I2C_M_RECV_LEN)) { >> + command |= ASPEED_I2CD_RX_BUFF_ENABLE; >> + >> + if (msg->len > bus->buf_size) { >> + len = bus->buf_size; >> + } else { >> + len = msg->len; >> + command |= ASPEED_I2CD_M_S_RX_CMD_LAST; >> + } >> + >> + writel(FIELD_PREP(ASPEED_I2CD_BUF_RX_SIZE_MASK, >> + len - 1) | >> + FIELD_PREP(ASPEED_I2CD_BUF_OFFSET_MASK, >> + bus->buf_offset), >> + bus->base + ASPEED_I2C_BUF_CTRL_REG); >> + } else { >> + /* Need to let the hardware know to NACK after RX. */ >> + if (msg->len == 1 && !(msg->flags & I2C_M_RECV_LEN)) >> + command |= ASPEED_I2CD_M_S_RX_CMD_LAST; >> + } >> + } else { >> + if (bus->buf_base) { >> + int i; >> + >> + command |= ASPEED_I2CD_TX_BUFF_ENABLE; >> + >> + if (msg->len + 1 > bus->buf_size) >> + len = bus->buf_size; >> + else >> + len = msg->len + 1; >> + >> + /* >> + * Yeah, it looks clumsy but byte writings on a remapped >> + * I2C SRAM cause corruptions so use this way to make >> + * dword writings. >> + */ >> + wbuf[0] = slave_addr; >> + for (i = 1; i < len; i++) { >> + wbuf[i % 4] = msg->buf[i - 1]; >> + if (i % 4 == 3) >> + writel(*(u32 *)wbuf, >> + bus->buf_base + i - 3); >> + } >> + if (--i % 4 != 3) >> + writel(*(u32 *)wbuf, >> + bus->buf_base + i - (i % 4)); >> + >> + bus->buf_index = len - 1; >> + >> + writel(FIELD_PREP(ASPEED_I2CD_BUF_TX_COUNT_MASK, >> + len - 1) | >> + FIELD_PREP(ASPEED_I2CD_BUF_OFFSET_MASK, >> + bus->buf_offset), >> + bus->base + ASPEED_I2C_BUF_CTRL_REG); >> + } >> } >> >> - writel(slave_addr, bus->base + ASPEED_I2C_BYTE_BUF_REG); >> + if (!(command & ASPEED_I2CD_TX_BUFF_ENABLE)) >> + writel(slave_addr, bus->base + ASPEED_I2C_BYTE_BUF_REG); >> writel(command, bus->base + ASPEED_I2C_CMD_REG); >> } >> >> @@ -398,7 +523,7 @@ static u32 aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus, u32 irq_status) >> u32 irq_handled = 0, command = 0; >> struct i2c_msg *msg; >> u8 recv_byte; >> - int ret; >> + int ret, len; >> >> if (irq_status & ASPEED_I2CD_INTR_BUS_RECOVER_DONE) { >> bus->master_state = ASPEED_I2C_MASTER_INACTIVE; >> @@ -511,11 +636,43 @@ static u32 aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus, u32 irq_status) >> /* fall through */ >> case ASPEED_I2C_MASTER_TX_FIRST: >> if (bus->buf_index < msg->len) { >> + command = ASPEED_I2CD_M_TX_CMD; >> + >> + if (bus->buf_base) { >> + u8 wbuf[4]; >> + int i; >> + >> + command |= ASPEED_I2CD_TX_BUFF_ENABLE; >> + >> + if (msg->len - bus->buf_index > bus->buf_size) >> + len = bus->buf_size; >> + else >> + len = msg->len - bus->buf_index; >> + >> + for (i = 0; i < len; i++) { >> + wbuf[i % 4] = msg->buf[bus->buf_index >> + + i]; >> + if (i % 4 == 3) >> + writel(*(u32 *)wbuf, >> + bus->buf_base + i - 3); >> + } >> + if (--i % 4 != 3) >> + writel(*(u32 *)wbuf, >> + bus->buf_base + i - (i % 4)); >> + >> + bus->buf_index += len; >> + >> + writel(FIELD_PREP(ASPEED_I2CD_BUF_TX_COUNT_MASK, >> + len - 1) | >> + FIELD_PREP(ASPEED_I2CD_BUF_OFFSET_MASK, >> + bus->buf_offset), >> + bus->base + ASPEED_I2C_BUF_CTRL_REG); >> + } else { >> + writel(msg->buf[bus->buf_index++], >> + bus->base + ASPEED_I2C_BYTE_BUF_REG); >> + } >> + writel(command, bus->base + ASPEED_I2C_CMD_REG); >> bus->master_state = ASPEED_I2C_MASTER_TX; >> - writel(msg->buf[bus->buf_index++], >> - bus->base + ASPEED_I2C_BYTE_BUF_REG); >> - writel(ASPEED_I2CD_M_TX_CMD, >> - bus->base + ASPEED_I2C_CMD_REG); >> } else { >> aspeed_i2c_next_msg_or_stop(bus); >> } >> @@ -532,25 +689,56 @@ static u32 aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus, u32 irq_status) >> } >> irq_handled |= ASPEED_I2CD_INTR_RX_DONE; >> >> - recv_byte = readl(bus->base + ASPEED_I2C_BYTE_BUF_REG) >> 8; >> - msg->buf[bus->buf_index++] = recv_byte; >> - >> - if (msg->flags & I2C_M_RECV_LEN) { >> - if (unlikely(recv_byte > I2C_SMBUS_BLOCK_MAX)) { >> - bus->cmd_err = -EPROTO; >> - aspeed_i2c_do_stop(bus); >> - goto out_no_complete; >> + if (bus->buf_base && !(msg->flags & I2C_M_RECV_LEN)) { >> + len = FIELD_GET(ASPEED_I2CD_BUF_RX_COUNT_MASK, >> + readl(bus->base + >> + ASPEED_I2C_BUF_CTRL_REG)); >> + memcpy_fromio(msg->buf + bus->buf_index, >> + bus->buf_base, len); >> + bus->buf_index += len; >> + } else { >> + recv_byte = readl(bus->base + ASPEED_I2C_BYTE_BUF_REG) >> + >> 8; >> + msg->buf[bus->buf_index++] = recv_byte; >> + >> + if (msg->flags & I2C_M_RECV_LEN) { >> + if (unlikely(recv_byte > I2C_SMBUS_BLOCK_MAX)) { >> + bus->cmd_err = -EPROTO; >> + aspeed_i2c_do_stop(bus); >> + goto out_no_complete; >> + } >> + msg->len = recv_byte + >> + ((msg->flags & I2C_CLIENT_PEC) ? >> + 2 : 1); >> + msg->flags &= ~I2C_M_RECV_LEN; >> } >> - msg->len = recv_byte + >> - ((msg->flags & I2C_CLIENT_PEC) ? 2 : 1); >> - msg->flags &= ~I2C_M_RECV_LEN; >> } >> >> if (bus->buf_index < msg->len) { >> - bus->master_state = ASPEED_I2C_MASTER_RX; >> command = ASPEED_I2CD_M_RX_CMD; >> - if (bus->buf_index + 1 == msg->len) >> - command |= ASPEED_I2CD_M_S_RX_CMD_LAST; >> + bus->master_state = ASPEED_I2C_MASTER_RX; >> + if (bus->buf_base) { >> + command |= ASPEED_I2CD_RX_BUFF_ENABLE; >> + >> + if (msg->len - bus->buf_index > >> + bus->buf_size) { >> + len = bus->buf_size; >> + } else { >> + len = msg->len - bus->buf_index; >> + command |= ASPEED_I2CD_M_S_RX_CMD_LAST; >> + } >> + >> + writel(FIELD_PREP(ASPEED_I2CD_BUF_RX_SIZE_MASK, >> + len - 1) | >> + FIELD_PREP(ASPEED_I2CD_BUF_TX_COUNT_MASK, >> + 0) | >> + FIELD_PREP(ASPEED_I2CD_BUF_OFFSET_MASK, >> + bus->buf_offset), >> + bus->base + ASPEED_I2C_BUF_CTRL_REG); >> + } else { >> + if (bus->buf_index + 1 == msg->len) >> + command |= ASPEED_I2CD_M_S_RX_CMD_LAST; >> + } >> writel(command, bus->base + ASPEED_I2C_CMD_REG); >> } else { >> aspeed_i2c_next_msg_or_stop(bus); >> @@ -890,6 +1078,9 @@ static int aspeed_i2c_init(struct aspeed_i2c_bus *bus, >> if (ret < 0) >> return ret; >> >> + fun_ctrl_reg |= FIELD_PREP(ASPEED_I2CD_BUFFER_PAGE_SEL_MASK, >> + bus->buf_page); >> + >> if (of_property_read_bool(pdev->dev.of_node, "multi-master")) >> bus->multi_master = true; >> else >> @@ -947,16 +1138,15 @@ static int aspeed_i2c_probe_bus(struct platform_device *pdev) >> { >> const struct of_device_id *match; >> struct aspeed_i2c_bus *bus; >> + bool sram_enabled = true; >> struct clk *parent_clk; >> - struct resource *res; >> int irq, ret; >> >> bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL); >> if (!bus) >> return -ENOMEM; >> >> - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); >> - bus->base = devm_ioremap_resource(&pdev->dev, res); >> + bus->base = devm_platform_ioremap_resource(pdev, 0); >> if (IS_ERR(bus->base)) >> return PTR_ERR(bus->base); >> >> @@ -990,6 +1180,45 @@ static int aspeed_i2c_probe_bus(struct platform_device *pdev) >> bus->get_clk_reg_val = (u32 (*)(struct device *, u32)) >> match->data; >> >> + /* >> + * Enable I2C SRAM in case of AST2500. >> + * SRAM is enabled by default in AST2400 and AST2600. >> + */ > > This probe function is already pretty complicated as it is. Can we move > this to a helper function (especially since it only applies to the > 25xx)? Okay, that would be better. I'll add this transfer mode setting logic as a helper function. >> + if (of_device_is_compatible(pdev->dev.of_node, >> + "aspeed,ast2500-i2c-bus")) { >> + struct regmap *gr_regmap = syscon_regmap_lookup_by_compatible("aspeed,ast2500-i2c-gr"); > > So this memory is global, right? It is shared by all the busses? Yes, this is global register area which can be shared by all busses. > If I am reading this right, then I think we need to protect so that only > one bus is accessing this memory at a time. It will not be accessed at run time but only at probing time. Since we don't use multi-threaded probing, we don't need to protect it. Thanks, Jae >> + if (IS_ERR(gr_regmap)) >> + ret = PTR_ERR(gr_regmap); >> + else >> + ret = regmap_update_bits(gr_regmap, >> + ASPEED_I2CG_GLOBAL_CTRL_REG, >> + ASPEED_I2CG_SRAM_BUFFER_EN, >> + ASPEED_I2CG_SRAM_BUFFER_EN); >> + >> + if (ret) >> + sram_enabled = false; >> + } >> + >> + if (sram_enabled) { >> + struct resource *res = platform_get_resource(pdev, >> + IORESOURCE_MEM, 1); >> + >> + if (res && resource_size(res) >= 2) >> + bus->buf_base = devm_ioremap_resource(&pdev->dev, res); >> + >> + if (!IS_ERR_OR_NULL(bus->buf_base)) { >> + bus->buf_size = resource_size(res); >> + if (of_device_is_compatible(pdev->dev.of_node, >> + "aspeed,ast2400-i2c-bus")) { >> + bus->buf_page = ((res->start >> 8) & >> + GENMASK(3, 0)) - 8; >> + bus->buf_offset = (res->start >> 2) & >> + ASPEED_I2CD_BUF_OFFSET_MASK; >> + } >> + } >> + } >> + >> /* Initialize the I2C adapter */ >> spin_lock_init(&bus->lock); >> init_completion(&bus->cmd_complete); >> @@ -1026,8 +1255,8 @@ static int aspeed_i2c_probe_bus(struct platform_device *pdev) >> >> platform_set_drvdata(pdev, bus); >> >> - dev_info(bus->dev, "i2c bus %d registered, irq %d\n", >> - bus->adap.nr, irq); >> + dev_info(bus->dev, "i2c bus %d registered (%s mode), irq %d\n", >> + bus->adap.nr, bus->buf_base ? "buffer" : "byte", irq); >> >> return 0; >> } >> -- >> 2.23.0 >> >
On Tue, Oct 8, 2019 at 2:10 PM Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com> wrote: > > Hi Brendan, > > On 10/8/2019 1:12 PM, Brendan Higgins wrote: > > On Mon, Oct 07, 2019 at 04:13:12PM -0700, Jae Hyun Yoo wrote: > >> Byte mode currently this driver uses makes lots of interrupt call > > > > nit: Drop "Byte mode". > > 'Byte mode' is one of modes which is described in the datasheet. > > Would it be better if I change it like below? > "This driver uses byte mode that makes lots of interrupt call ..." Yeah, I think that would probably be clearer. > >> which isn't good for performance and it makes the driver very > >> timing sensitive. To improve performance of the driver, this commit > >> adds buffer mode transfer support which uses I2C SRAM buffer > >> instead of using a single byte buffer. > > > > nit: Please use imperative mood. > > I used imperative mood in commit title. The commit message is okay as it > is. Hey, that's just what I have been told in the past. I don't actually feel strongly about it though. If no one else cares, then it is fine. > >> Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com> > >> Tested-by: Tao Ren <taoren@fb.com> > >> --- > >> drivers/i2c/busses/i2c-aspeed.c | 297 ++++++++++++++++++++++++++++---- > >> 1 file changed, 263 insertions(+), 34 deletions(-) > >> > >> diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c > >> index 40f6cf98d32e..37d1a7fa2f87 100644 > >> --- a/drivers/i2c/busses/i2c-aspeed.c > >> +++ b/drivers/i2c/busses/i2c-aspeed.c [...] > >> @@ -238,6 +260,7 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) > >> { > >> u32 command, irq_handled = 0; > >> struct i2c_client *slave = bus->slave; > >> + int i, len; > >> u8 value; > >> > >> if (!slave) > >> @@ -260,7 +283,12 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) > >> > >> /* Slave was sent something. */ > >> if (irq_status & ASPEED_I2CD_INTR_RX_DONE) { > >> - value = readl(bus->base + ASPEED_I2C_BYTE_BUF_REG) >> 8; > >> + if (bus->buf_base && > >> + bus->slave_state == ASPEED_I2C_SLAVE_WRITE_RECEIVED && > >> + !(irq_status & ASPEED_I2CD_INTR_NORMAL_STOP)) > > > > I think checking for the buf_base all over the place makes this really > > complicated and hard to read. > > > > It might be better to just split this out and have separate handlers > > based on what mode the driver is running in. > > I think you're saying about splitting this irq handler out to: > aspeed_i2c_slave_byte_mode_irq() > aspeed_i2c_slave_buffer_mode_irq() > aspeed_i2c_slave_dma_mode_irq() > > Yes, I can do like that but it will bring us two bad things: > 1. It makes big chunks of duplicate code because most of interrupt > handling logic is the same. > 2. If we are going to change something in irq routine, we need to > touch all irq routines if the change is commonly used. > > I think, the way this patch uses is better. I think there are other alternatives. For example, I think you could abstract over the buffer reading mechanism here. We might have a method on aspeed_i2c_bus called handle_rx_done() or something like that which could get called here. I just really don't want to grow the McCabe's complexity of this function much more, it is really too high as it is. Nevertheless, I am open to other suggestions on how to improve this function. > >> + value = readb(bus->buf_base); > >> + else > >> + value = readl(bus->base + ASPEED_I2C_BYTE_BUF_REG) >> 8; > >> /* Handle address frame. */ > >> if (bus->slave_state == ASPEED_I2C_SLAVE_START) { > >> if (value & 0x1) > >> @@ -275,6 +303,20 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) > >> > >> /* Slave was asked to stop. */ > >> if (irq_status & ASPEED_I2CD_INTR_NORMAL_STOP) { > >> + if (bus->slave_state == ASPEED_I2C_SLAVE_WRITE_RECEIVED && > >> + irq_status & ASPEED_I2CD_INTR_RX_DONE) { > >> + if (bus->buf_base) { > >> + len = FIELD_GET(ASPEED_I2CD_BUF_RX_COUNT_MASK, > >> + readl(bus->base + > >> + ASPEED_I2C_BUF_CTRL_REG)); > > > > It looks like you have a lot of improvements in here unrelated to adding > > support for buffer mode. > > > > I really appreciate the improvements, but it makes it harder to > > understand what buffer features you are adding vs. what > > improvments/modernizations you are making. > > > > Can you split this commit up? > > No, this isn't an improvement. This code will not be executed if > transfer mode is byte mode. This is added because data handling pattern > is different in buffer mode so the collected data in buffer mode should > be sent when it recieves RX_DONE. Oh sorry about that, I saw the switch to the devm_platform_ioremap_resource below and saw all the FIELD_{GET|PREP} and assumed that some of them were improvements. If devm_platform_ioremap_resource is the only one, that's fine. Actually, would you mind (in a separate commit), update the existing usages to FIELD_{GET|PREP}? It's kind of jarring going back and forth between them. > >> + for (i = 0; i < len; i++) { > >> + value = readb(bus->buf_base + i); > >> + i2c_slave_event(slave, > >> + I2C_SLAVE_WRITE_RECEIVED, > >> + &value); > >> + } > >> + } > >> + } > >> irq_handled |= ASPEED_I2CD_INTR_NORMAL_STOP; > >> bus->slave_state = ASPEED_I2C_SLAVE_STOP; > >> } [....] > >> @@ -990,6 +1180,45 @@ static int aspeed_i2c_probe_bus(struct platform_device *pdev) > >> bus->get_clk_reg_val = (u32 (*)(struct device *, u32)) > >> match->data; > >> > >> + /* > >> + * Enable I2C SRAM in case of AST2500. > >> + * SRAM is enabled by default in AST2400 and AST2600. > >> + */ > > > > This probe function is already pretty complicated as it is. Can we move > > this to a helper function (especially since it only applies to the > > 25xx)? > > Okay, that would be better. I'll add this transfer mode setting logic > as a helper function. > > >> + if (of_device_is_compatible(pdev->dev.of_node, > >> + "aspeed,ast2500-i2c-bus")) { > >> + struct regmap *gr_regmap = syscon_regmap_lookup_by_compatible("aspeed,ast2500-i2c-gr"); > > > > So this memory is global, right? It is shared by all the busses? > > Yes, this is global register area which can be shared by all busses. > > > If I am reading this right, then I think we need to protect so that only > > one bus is accessing this memory at a time. > > It will not be accessed at run time but only at probing time. Since we > don't use multi-threaded probing, we don't need to protect it. What if this is loaded as a module? Also, it seems as though turning on SRAM should only happen once. Is this correct? > >> + if (IS_ERR(gr_regmap)) > >> + ret = PTR_ERR(gr_regmap); > >> + else > >> + ret = regmap_update_bits(gr_regmap, > >> + ASPEED_I2CG_GLOBAL_CTRL_REG, > >> + ASPEED_I2CG_SRAM_BUFFER_EN, > >> + ASPEED_I2CG_SRAM_BUFFER_EN); > >> + > >> + if (ret) > >> + sram_enabled = false; > >> + } > >> + > >> + if (sram_enabled) { > >> + struct resource *res = platform_get_resource(pdev, > >> + IORESOURCE_MEM, 1); > >> + > >> + if (res && resource_size(res) >= 2) > >> + bus->buf_base = devm_ioremap_resource(&pdev->dev, res); > >> + > >> + if (!IS_ERR_OR_NULL(bus->buf_base)) { > >> + bus->buf_size = resource_size(res); > >> + if (of_device_is_compatible(pdev->dev.of_node, > >> + "aspeed,ast2400-i2c-bus")) { > >> + bus->buf_page = ((res->start >> 8) & > >> + GENMASK(3, 0)) - 8; > >> + bus->buf_offset = (res->start >> 2) & > >> + ASPEED_I2CD_BUF_OFFSET_MASK; > >> + } > >> + } > >> + } [...] Cheers
On 10/8/2019 4:15 PM, Brendan Higgins wrote: > On Tue, Oct 8, 2019 at 2:10 PM Jae Hyun Yoo > <jae.hyun.yoo@linux.intel.com> wrote: >> >> Hi Brendan, >> >> On 10/8/2019 1:12 PM, Brendan Higgins wrote: >>> On Mon, Oct 07, 2019 at 04:13:12PM -0700, Jae Hyun Yoo wrote: >>>> Byte mode currently this driver uses makes lots of interrupt call >>> >>> nit: Drop "Byte mode". >> >> 'Byte mode' is one of modes which is described in the datasheet. >> >> Would it be better if I change it like below? >> "This driver uses byte mode that makes lots of interrupt call ..." > > Yeah, I think that would probably be clearer. Okay. Will change it. >>>> which isn't good for performance and it makes the driver very >>>> timing sensitive. To improve performance of the driver, this commit >>>> adds buffer mode transfer support which uses I2C SRAM buffer >>>> instead of using a single byte buffer. >>> >>> nit: Please use imperative mood. >> >> I used imperative mood in commit title. The commit message is okay as it >> is. > > Hey, that's just what I have been told in the past. I don't actually > feel strongly about it though. If no one else cares, then it is fine. Yeah, I suggested that in the past on a commit title of your patch not on a commit message body. Anyway, it's not a strict rule. >>>> Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com> >>>> Tested-by: Tao Ren <taoren@fb.com> >>>> --- >>>> drivers/i2c/busses/i2c-aspeed.c | 297 ++++++++++++++++++++++++++++---- >>>> 1 file changed, 263 insertions(+), 34 deletions(-) >>>> >>>> diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c >>>> index 40f6cf98d32e..37d1a7fa2f87 100644 >>>> --- a/drivers/i2c/busses/i2c-aspeed.c >>>> +++ b/drivers/i2c/busses/i2c-aspeed.c > [...] >>>> @@ -238,6 +260,7 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) >>>> { >>>> u32 command, irq_handled = 0; >>>> struct i2c_client *slave = bus->slave; >>>> + int i, len; >>>> u8 value; >>>> >>>> if (!slave) >>>> @@ -260,7 +283,12 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) >>>> >>>> /* Slave was sent something. */ >>>> if (irq_status & ASPEED_I2CD_INTR_RX_DONE) { >>>> - value = readl(bus->base + ASPEED_I2C_BYTE_BUF_REG) >> 8; >>>> + if (bus->buf_base && >>>> + bus->slave_state == ASPEED_I2C_SLAVE_WRITE_RECEIVED && >>>> + !(irq_status & ASPEED_I2CD_INTR_NORMAL_STOP)) >>> >>> I think checking for the buf_base all over the place makes this really >>> complicated and hard to read. >>> >>> It might be better to just split this out and have separate handlers >>> based on what mode the driver is running in. >> >> I think you're saying about splitting this irq handler out to: >> aspeed_i2c_slave_byte_mode_irq() >> aspeed_i2c_slave_buffer_mode_irq() >> aspeed_i2c_slave_dma_mode_irq() >> >> Yes, I can do like that but it will bring us two bad things: >> 1. It makes big chunks of duplicate code because most of interrupt >> handling logic is the same. >> 2. If we are going to change something in irq routine, we need to >> touch all irq routines if the change is commonly used. >> >> I think, the way this patch uses is better. > > I think there are other alternatives. For example, I think you could > abstract over the buffer reading mechanism here. > > We might have a method on aspeed_i2c_bus called handle_rx_done() or > something like that which could get called here. > > I just really don't want to grow the McCabe's complexity of this > function much more, it is really too high as it is. Nevertheless, I am > open to other suggestions on how to improve this function. Okay, Using of abstract functions would be a better way to simplify it. Will update it in the next spin. >>>> + value = readb(bus->buf_base); >>>> + else >>>> + value = readl(bus->base + ASPEED_I2C_BYTE_BUF_REG) >> 8; >>>> /* Handle address frame. */ >>>> if (bus->slave_state == ASPEED_I2C_SLAVE_START) { >>>> if (value & 0x1) >>>> @@ -275,6 +303,20 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) >>>> >>>> /* Slave was asked to stop. */ >>>> if (irq_status & ASPEED_I2CD_INTR_NORMAL_STOP) { >>>> + if (bus->slave_state == ASPEED_I2C_SLAVE_WRITE_RECEIVED && >>>> + irq_status & ASPEED_I2CD_INTR_RX_DONE) { >>>> + if (bus->buf_base) { >>>> + len = FIELD_GET(ASPEED_I2CD_BUF_RX_COUNT_MASK, >>>> + readl(bus->base + >>>> + ASPEED_I2C_BUF_CTRL_REG)); >>> >>> It looks like you have a lot of improvements in here unrelated to adding >>> support for buffer mode. >>> >>> I really appreciate the improvements, but it makes it harder to >>> understand what buffer features you are adding vs. what >>> improvments/modernizations you are making. >>> >>> Can you split this commit up? >> >> No, this isn't an improvement. This code will not be executed if >> transfer mode is byte mode. This is added because data handling pattern >> is different in buffer mode so the collected data in buffer mode should >> be sent when it recieves RX_DONE. > > Oh sorry about that, I saw the switch to the > devm_platform_ioremap_resource below and saw all the FIELD_{GET|PREP} > and assumed that some of them were improvements. If > devm_platform_ioremap_resource is the only one, that's fine. > > Actually, would you mind (in a separate commit), update the existing > usages to FIELD_{GET|PREP}? It's kind of jarring going back and forth > between them. No. Will do that later using a separate commit. >>>> + for (i = 0; i < len; i++) { >>>> + value = readb(bus->buf_base + i); >>>> + i2c_slave_event(slave, >>>> + I2C_SLAVE_WRITE_RECEIVED, >>>> + &value); >>>> + } >>>> + } >>>> + } >>>> irq_handled |= ASPEED_I2CD_INTR_NORMAL_STOP; >>>> bus->slave_state = ASPEED_I2C_SLAVE_STOP; >>>> } > [....] >>>> @@ -990,6 +1180,45 @@ static int aspeed_i2c_probe_bus(struct platform_device *pdev) >>>> bus->get_clk_reg_val = (u32 (*)(struct device *, u32)) >>>> match->data; >>>> >>>> + /* >>>> + * Enable I2C SRAM in case of AST2500. >>>> + * SRAM is enabled by default in AST2400 and AST2600. >>>> + */ >>> >>> This probe function is already pretty complicated as it is. Can we move >>> this to a helper function (especially since it only applies to the >>> 25xx)? >> >> Okay, that would be better. I'll add this transfer mode setting logic >> as a helper function. >> >>>> + if (of_device_is_compatible(pdev->dev.of_node, >>>> + "aspeed,ast2500-i2c-bus")) { >>>> + struct regmap *gr_regmap = syscon_regmap_lookup_by_compatible("aspeed,ast2500-i2c-gr"); >>> >>> So this memory is global, right? It is shared by all the busses? >> >> Yes, this is global register area which can be shared by all busses. >> >>> If I am reading this right, then I think we need to protect so that only >>> one bus is accessing this memory at a time. >> >> It will not be accessed at run time but only at probing time. Since we >> don't use multi-threaded probing, we don't need to protect it. > > What if this is loaded as a module? Loading modules at the same time? This driver just enables the bit. It doesn't have a bit clearing code so it would be safe even in that case. Actually, I2C SRAM doesn't need to be disabled, means that the SRAM can be left as enabled for all xfer modes. It's an unnecessary control so Aspeed removed this register setting in AST2600 after enabling the SRAM always by default. > Also, it seems as though turning on SRAM should only happen once. Is > this correct? It's a global setting which affects all busses so it can be set just once. Since we don't need to clear the bit, each bus driver enables the bit without checking the bit that is simple way. Thanks, Jae >>>> + if (IS_ERR(gr_regmap)) >>>> + ret = PTR_ERR(gr_regmap); >>>> + else >>>> + ret = regmap_update_bits(gr_regmap, >>>> + ASPEED_I2CG_GLOBAL_CTRL_REG, >>>> + ASPEED_I2CG_SRAM_BUFFER_EN, >>>> + ASPEED_I2CG_SRAM_BUFFER_EN); >>>> + >>>> + if (ret) >>>> + sram_enabled = false; >>>> + } >>>> + >>>> + if (sram_enabled) { >>>> + struct resource *res = platform_get_resource(pdev, >>>> + IORESOURCE_MEM, 1); >>>> + >>>> + if (res && resource_size(res) >= 2) >>>> + bus->buf_base = devm_ioremap_resource(&pdev->dev, res); >>>> + >>>> + if (!IS_ERR_OR_NULL(bus->buf_base)) { >>>> + bus->buf_size = resource_size(res); >>>> + if (of_device_is_compatible(pdev->dev.of_node, >>>> + "aspeed,ast2400-i2c-bus")) { >>>> + bus->buf_page = ((res->start >> 8) & >>>> + GENMASK(3, 0)) - 8; >>>> + bus->buf_offset = (res->start >> 2) & >>>> + ASPEED_I2CD_BUF_OFFSET_MASK; >>>> + } >>>> + } >>>> + } > [...] > > Cheers >
diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c index 40f6cf98d32e..37d1a7fa2f87 100644 --- a/drivers/i2c/busses/i2c-aspeed.c +++ b/drivers/i2c/busses/i2c-aspeed.c @@ -7,6 +7,7 @@ * Copyright 2017 Google, Inc. */ +#include <linux/bitfield.h> #include <linux/clk.h> #include <linux/completion.h> #include <linux/err.h> @@ -19,15 +20,24 @@ #include <linux/irqchip/chained_irq.h> #include <linux/irqdomain.h> #include <linux/kernel.h> +#include <linux/mfd/syscon.h> #include <linux/module.h> #include <linux/of_address.h> #include <linux/of_irq.h> #include <linux/of_platform.h> #include <linux/platform_device.h> +#include <linux/regmap.h> #include <linux/reset.h> #include <linux/slab.h> -/* I2C Register */ +/* I2C Global Registers */ +/* 0x00 : I2CG Interrupt Status Register */ +/* 0x08 : I2CG Interrupt Target Assignment */ +/* 0x0c : I2CG Global Control Register (AST2500) */ +#define ASPEED_I2CG_GLOBAL_CTRL_REG 0x0c +#define ASPEED_I2CG_SRAM_BUFFER_EN BIT(0) + +/* I2C Bus Registers */ #define ASPEED_I2C_FUN_CTRL_REG 0x00 #define ASPEED_I2C_AC_TIMING_REG1 0x04 #define ASPEED_I2C_AC_TIMING_REG2 0x08 @@ -35,14 +45,12 @@ #define ASPEED_I2C_INTR_STS_REG 0x10 #define ASPEED_I2C_CMD_REG 0x14 #define ASPEED_I2C_DEV_ADDR_REG 0x18 +#define ASPEED_I2C_BUF_CTRL_REG 0x1c #define ASPEED_I2C_BYTE_BUF_REG 0x20 -/* Global Register Definition */ -/* 0x00 : I2C Interrupt Status Register */ -/* 0x08 : I2C Interrupt Target Assignment */ - /* Device Register Definition */ /* 0x00 : I2CD Function Control Register */ +#define ASPEED_I2CD_BUFFER_PAGE_SEL_MASK GENMASK(22, 20) #define ASPEED_I2CD_MULTI_MASTER_DIS BIT(15) #define ASPEED_I2CD_SDA_DRIVE_1T_EN BIT(8) #define ASPEED_I2CD_M_SDA_DRIVE_1T_EN BIT(7) @@ -102,6 +110,8 @@ #define ASPEED_I2CD_BUS_RECOVER_CMD BIT(11) /* Command Bit */ +#define ASPEED_I2CD_RX_BUFF_ENABLE BIT(7) +#define ASPEED_I2CD_TX_BUFF_ENABLE BIT(6) #define ASPEED_I2CD_M_STOP_CMD BIT(5) #define ASPEED_I2CD_M_S_RX_CMD_LAST BIT(4) #define ASPEED_I2CD_M_RX_CMD BIT(3) @@ -112,6 +122,13 @@ /* 0x18 : I2CD Slave Device Address Register */ #define ASPEED_I2CD_DEV_ADDR_MASK GENMASK(6, 0) +/* 0x1c : I2CD Buffer Control Register */ +/* Use 8-bits or 6-bits wide bit fileds to support both AST2400 and AST2500 */ +#define ASPEED_I2CD_BUF_RX_COUNT_MASK GENMASK(31, 24) +#define ASPEED_I2CD_BUF_RX_SIZE_MASK GENMASK(23, 16) +#define ASPEED_I2CD_BUF_TX_COUNT_MASK GENMASK(15, 8) +#define ASPEED_I2CD_BUF_OFFSET_MASK GENMASK(5, 0) + enum aspeed_i2c_master_state { ASPEED_I2C_MASTER_INACTIVE, ASPEED_I2C_MASTER_PENDING, @@ -157,6 +174,11 @@ struct aspeed_i2c_bus { int master_xfer_result; /* Multi-master */ bool multi_master; + /* Buffer mode */ + void __iomem *buf_base; + size_t buf_size; + u8 buf_offset; + u8 buf_page; #if IS_ENABLED(CONFIG_I2C_SLAVE) struct i2c_client *slave; enum aspeed_i2c_slave_state slave_state; @@ -238,6 +260,7 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) { u32 command, irq_handled = 0; struct i2c_client *slave = bus->slave; + int i, len; u8 value; if (!slave) @@ -260,7 +283,12 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) /* Slave was sent something. */ if (irq_status & ASPEED_I2CD_INTR_RX_DONE) { - value = readl(bus->base + ASPEED_I2C_BYTE_BUF_REG) >> 8; + if (bus->buf_base && + bus->slave_state == ASPEED_I2C_SLAVE_WRITE_RECEIVED && + !(irq_status & ASPEED_I2CD_INTR_NORMAL_STOP)) + value = readb(bus->buf_base); + else + value = readl(bus->base + ASPEED_I2C_BYTE_BUF_REG) >> 8; /* Handle address frame. */ if (bus->slave_state == ASPEED_I2C_SLAVE_START) { if (value & 0x1) @@ -275,6 +303,20 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) /* Slave was asked to stop. */ if (irq_status & ASPEED_I2CD_INTR_NORMAL_STOP) { + if (bus->slave_state == ASPEED_I2C_SLAVE_WRITE_RECEIVED && + irq_status & ASPEED_I2CD_INTR_RX_DONE) { + if (bus->buf_base) { + len = FIELD_GET(ASPEED_I2CD_BUF_RX_COUNT_MASK, + readl(bus->base + + ASPEED_I2C_BUF_CTRL_REG)); + for (i = 0; i < len; i++) { + value = readb(bus->buf_base + i); + i2c_slave_event(slave, + I2C_SLAVE_WRITE_RECEIVED, + &value); + } + } + } irq_handled |= ASPEED_I2CD_INTR_NORMAL_STOP; bus->slave_state = ASPEED_I2C_SLAVE_STOP; } @@ -307,9 +349,36 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) case ASPEED_I2C_SLAVE_WRITE_REQUESTED: bus->slave_state = ASPEED_I2C_SLAVE_WRITE_RECEIVED; i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value); + if (bus->buf_base) { + writel(FIELD_PREP(ASPEED_I2CD_BUF_RX_SIZE_MASK, + bus->buf_size - 1) | + FIELD_PREP(ASPEED_I2CD_BUF_OFFSET_MASK, + bus->buf_offset), + bus->base + ASPEED_I2C_BUF_CTRL_REG); + writel(ASPEED_I2CD_RX_BUFF_ENABLE, + bus->base + ASPEED_I2C_CMD_REG); + } break; case ASPEED_I2C_SLAVE_WRITE_RECEIVED: i2c_slave_event(slave, I2C_SLAVE_WRITE_RECEIVED, &value); + if (bus->buf_base) { + len = FIELD_GET(ASPEED_I2CD_BUF_RX_COUNT_MASK, + readl(bus->base + + ASPEED_I2C_BUF_CTRL_REG)); + for (i = 1; i < len; i++) { + value = readb(bus->buf_base + i); + i2c_slave_event(slave, + I2C_SLAVE_WRITE_RECEIVED, + &value); + } + writel(FIELD_PREP(ASPEED_I2CD_BUF_RX_SIZE_MASK, + bus->buf_size - 1) | + FIELD_PREP(ASPEED_I2CD_BUF_OFFSET_MASK, + bus->buf_offset), + bus->base + ASPEED_I2C_BUF_CTRL_REG); + writel(ASPEED_I2CD_RX_BUFF_ENABLE, + bus->base + ASPEED_I2C_CMD_REG); + } break; case ASPEED_I2C_SLAVE_STOP: i2c_slave_event(slave, I2C_SLAVE_STOP, &value); @@ -335,6 +404,8 @@ static void aspeed_i2c_do_start(struct aspeed_i2c_bus *bus) u32 command = ASPEED_I2CD_M_START_CMD | ASPEED_I2CD_M_TX_CMD; struct i2c_msg *msg = &bus->msgs[bus->msgs_index]; u8 slave_addr = i2c_8bit_addr_from_msg(msg); + u8 wbuf[4]; + int len; #if IS_ENABLED(CONFIG_I2C_SLAVE) /* @@ -353,12 +424,66 @@ static void aspeed_i2c_do_start(struct aspeed_i2c_bus *bus) if (msg->flags & I2C_M_RD) { command |= ASPEED_I2CD_M_RX_CMD; - /* Need to let the hardware know to NACK after RX. */ - if (msg->len == 1 && !(msg->flags & I2C_M_RECV_LEN)) - command |= ASPEED_I2CD_M_S_RX_CMD_LAST; + + if (bus->buf_base && !(msg->flags & I2C_M_RECV_LEN)) { + command |= ASPEED_I2CD_RX_BUFF_ENABLE; + + if (msg->len > bus->buf_size) { + len = bus->buf_size; + } else { + len = msg->len; + command |= ASPEED_I2CD_M_S_RX_CMD_LAST; + } + + writel(FIELD_PREP(ASPEED_I2CD_BUF_RX_SIZE_MASK, + len - 1) | + FIELD_PREP(ASPEED_I2CD_BUF_OFFSET_MASK, + bus->buf_offset), + bus->base + ASPEED_I2C_BUF_CTRL_REG); + } else { + /* Need to let the hardware know to NACK after RX. */ + if (msg->len == 1 && !(msg->flags & I2C_M_RECV_LEN)) + command |= ASPEED_I2CD_M_S_RX_CMD_LAST; + } + } else { + if (bus->buf_base) { + int i; + + command |= ASPEED_I2CD_TX_BUFF_ENABLE; + + if (msg->len + 1 > bus->buf_size) + len = bus->buf_size; + else + len = msg->len + 1; + + /* + * Yeah, it looks clumsy but byte writings on a remapped + * I2C SRAM cause corruptions so use this way to make + * dword writings. + */ + wbuf[0] = slave_addr; + for (i = 1; i < len; i++) { + wbuf[i % 4] = msg->buf[i - 1]; + if (i % 4 == 3) + writel(*(u32 *)wbuf, + bus->buf_base + i - 3); + } + if (--i % 4 != 3) + writel(*(u32 *)wbuf, + bus->buf_base + i - (i % 4)); + + bus->buf_index = len - 1; + + writel(FIELD_PREP(ASPEED_I2CD_BUF_TX_COUNT_MASK, + len - 1) | + FIELD_PREP(ASPEED_I2CD_BUF_OFFSET_MASK, + bus->buf_offset), + bus->base + ASPEED_I2C_BUF_CTRL_REG); + } } - writel(slave_addr, bus->base + ASPEED_I2C_BYTE_BUF_REG); + if (!(command & ASPEED_I2CD_TX_BUFF_ENABLE)) + writel(slave_addr, bus->base + ASPEED_I2C_BYTE_BUF_REG); writel(command, bus->base + ASPEED_I2C_CMD_REG); } @@ -398,7 +523,7 @@ static u32 aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus, u32 irq_status) u32 irq_handled = 0, command = 0; struct i2c_msg *msg; u8 recv_byte; - int ret; + int ret, len; if (irq_status & ASPEED_I2CD_INTR_BUS_RECOVER_DONE) { bus->master_state = ASPEED_I2C_MASTER_INACTIVE; @@ -511,11 +636,43 @@ static u32 aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus, u32 irq_status) /* fall through */ case ASPEED_I2C_MASTER_TX_FIRST: if (bus->buf_index < msg->len) { + command = ASPEED_I2CD_M_TX_CMD; + + if (bus->buf_base) { + u8 wbuf[4]; + int i; + + command |= ASPEED_I2CD_TX_BUFF_ENABLE; + + if (msg->len - bus->buf_index > bus->buf_size) + len = bus->buf_size; + else + len = msg->len - bus->buf_index; + + for (i = 0; i < len; i++) { + wbuf[i % 4] = msg->buf[bus->buf_index + + i]; + if (i % 4 == 3) + writel(*(u32 *)wbuf, + bus->buf_base + i - 3); + } + if (--i % 4 != 3) + writel(*(u32 *)wbuf, + bus->buf_base + i - (i % 4)); + + bus->buf_index += len; + + writel(FIELD_PREP(ASPEED_I2CD_BUF_TX_COUNT_MASK, + len - 1) | + FIELD_PREP(ASPEED_I2CD_BUF_OFFSET_MASK, + bus->buf_offset), + bus->base + ASPEED_I2C_BUF_CTRL_REG); + } else { + writel(msg->buf[bus->buf_index++], + bus->base + ASPEED_I2C_BYTE_BUF_REG); + } + writel(command, bus->base + ASPEED_I2C_CMD_REG); bus->master_state = ASPEED_I2C_MASTER_TX; - writel(msg->buf[bus->buf_index++], - bus->base + ASPEED_I2C_BYTE_BUF_REG); - writel(ASPEED_I2CD_M_TX_CMD, - bus->base + ASPEED_I2C_CMD_REG); } else { aspeed_i2c_next_msg_or_stop(bus); } @@ -532,25 +689,56 @@ static u32 aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus, u32 irq_status) } irq_handled |= ASPEED_I2CD_INTR_RX_DONE; - recv_byte = readl(bus->base + ASPEED_I2C_BYTE_BUF_REG) >> 8; - msg->buf[bus->buf_index++] = recv_byte; - - if (msg->flags & I2C_M_RECV_LEN) { - if (unlikely(recv_byte > I2C_SMBUS_BLOCK_MAX)) { - bus->cmd_err = -EPROTO; - aspeed_i2c_do_stop(bus); - goto out_no_complete; + if (bus->buf_base && !(msg->flags & I2C_M_RECV_LEN)) { + len = FIELD_GET(ASPEED_I2CD_BUF_RX_COUNT_MASK, + readl(bus->base + + ASPEED_I2C_BUF_CTRL_REG)); + memcpy_fromio(msg->buf + bus->buf_index, + bus->buf_base, len); + bus->buf_index += len; + } else { + recv_byte = readl(bus->base + ASPEED_I2C_BYTE_BUF_REG) + >> 8; + msg->buf[bus->buf_index++] = recv_byte; + + if (msg->flags & I2C_M_RECV_LEN) { + if (unlikely(recv_byte > I2C_SMBUS_BLOCK_MAX)) { + bus->cmd_err = -EPROTO; + aspeed_i2c_do_stop(bus); + goto out_no_complete; + } + msg->len = recv_byte + + ((msg->flags & I2C_CLIENT_PEC) ? + 2 : 1); + msg->flags &= ~I2C_M_RECV_LEN; } - msg->len = recv_byte + - ((msg->flags & I2C_CLIENT_PEC) ? 2 : 1); - msg->flags &= ~I2C_M_RECV_LEN; } if (bus->buf_index < msg->len) { - bus->master_state = ASPEED_I2C_MASTER_RX; command = ASPEED_I2CD_M_RX_CMD; - if (bus->buf_index + 1 == msg->len) - command |= ASPEED_I2CD_M_S_RX_CMD_LAST; + bus->master_state = ASPEED_I2C_MASTER_RX; + if (bus->buf_base) { + command |= ASPEED_I2CD_RX_BUFF_ENABLE; + + if (msg->len - bus->buf_index > + bus->buf_size) { + len = bus->buf_size; + } else { + len = msg->len - bus->buf_index; + command |= ASPEED_I2CD_M_S_RX_CMD_LAST; + } + + writel(FIELD_PREP(ASPEED_I2CD_BUF_RX_SIZE_MASK, + len - 1) | + FIELD_PREP(ASPEED_I2CD_BUF_TX_COUNT_MASK, + 0) | + FIELD_PREP(ASPEED_I2CD_BUF_OFFSET_MASK, + bus->buf_offset), + bus->base + ASPEED_I2C_BUF_CTRL_REG); + } else { + if (bus->buf_index + 1 == msg->len) + command |= ASPEED_I2CD_M_S_RX_CMD_LAST; + } writel(command, bus->base + ASPEED_I2C_CMD_REG); } else { aspeed_i2c_next_msg_or_stop(bus); @@ -890,6 +1078,9 @@ static int aspeed_i2c_init(struct aspeed_i2c_bus *bus, if (ret < 0) return ret; + fun_ctrl_reg |= FIELD_PREP(ASPEED_I2CD_BUFFER_PAGE_SEL_MASK, + bus->buf_page); + if (of_property_read_bool(pdev->dev.of_node, "multi-master")) bus->multi_master = true; else @@ -947,16 +1138,15 @@ static int aspeed_i2c_probe_bus(struct platform_device *pdev) { const struct of_device_id *match; struct aspeed_i2c_bus *bus; + bool sram_enabled = true; struct clk *parent_clk; - struct resource *res; int irq, ret; bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL); if (!bus) return -ENOMEM; - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - bus->base = devm_ioremap_resource(&pdev->dev, res); + bus->base = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(bus->base)) return PTR_ERR(bus->base); @@ -990,6 +1180,45 @@ static int aspeed_i2c_probe_bus(struct platform_device *pdev) bus->get_clk_reg_val = (u32 (*)(struct device *, u32)) match->data; + /* + * Enable I2C SRAM in case of AST2500. + * SRAM is enabled by default in AST2400 and AST2600. + */ + if (of_device_is_compatible(pdev->dev.of_node, + "aspeed,ast2500-i2c-bus")) { + struct regmap *gr_regmap = syscon_regmap_lookup_by_compatible("aspeed,ast2500-i2c-gr"); + + if (IS_ERR(gr_regmap)) + ret = PTR_ERR(gr_regmap); + else + ret = regmap_update_bits(gr_regmap, + ASPEED_I2CG_GLOBAL_CTRL_REG, + ASPEED_I2CG_SRAM_BUFFER_EN, + ASPEED_I2CG_SRAM_BUFFER_EN); + + if (ret) + sram_enabled = false; + } + + if (sram_enabled) { + struct resource *res = platform_get_resource(pdev, + IORESOURCE_MEM, 1); + + if (res && resource_size(res) >= 2) + bus->buf_base = devm_ioremap_resource(&pdev->dev, res); + + if (!IS_ERR_OR_NULL(bus->buf_base)) { + bus->buf_size = resource_size(res); + if (of_device_is_compatible(pdev->dev.of_node, + "aspeed,ast2400-i2c-bus")) { + bus->buf_page = ((res->start >> 8) & + GENMASK(3, 0)) - 8; + bus->buf_offset = (res->start >> 2) & + ASPEED_I2CD_BUF_OFFSET_MASK; + } + } + } + /* Initialize the I2C adapter */ spin_lock_init(&bus->lock); init_completion(&bus->cmd_complete); @@ -1026,8 +1255,8 @@ static int aspeed_i2c_probe_bus(struct platform_device *pdev) platform_set_drvdata(pdev, bus); - dev_info(bus->dev, "i2c bus %d registered, irq %d\n", - bus->adap.nr, irq); + dev_info(bus->dev, "i2c bus %d registered (%s mode), irq %d\n", + bus->adap.nr, bus->buf_base ? "buffer" : "byte", irq); return 0; }