[PATCH v4 3/4] i2c: aspeed: add buffer mode transfer support
Jae Hyun Yoo
jae.hyun.yoo at linux.intel.com
Thu Feb 25 06:17:19 AEDT 2021
This driver uses byte mode that makes lots of interrupt calls
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.
Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo at linux.intel.com>
Tested-by: Tao Ren <taoren at fb.com>
---
Changes since v3:
- Added a comment to explain SRAM buffer handling logic.
Changes since v2:
- Refined SoC family dependent xfer mode configuration functions.
Changes since v1:
- Updated commit message.
- Refined using abstract functions.
drivers/i2c/busses/i2c-aspeed.c | 468 ++++++++++++++++++++++++++++----
1 file changed, 416 insertions(+), 52 deletions(-)
diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c
index 724bf30600d6..ffc52937df26 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)
@@ -103,6 +111,8 @@
#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)
@@ -119,6 +129,13 @@
/* 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,
@@ -140,6 +157,12 @@ enum aspeed_i2c_slave_state {
ASPEED_I2C_SLAVE_STOP,
};
+struct aspeed_i2c_config {
+ u32 (*get_clk_reg_val)(struct device *dev, u32 divisor);
+ int (*enable_sram)(void);
+ int (*set_buf_xfer_mode)(struct device *dev);
+};
+
struct aspeed_i2c_bus {
struct i2c_adapter adap;
struct device *dev;
@@ -148,8 +171,7 @@ struct aspeed_i2c_bus {
/* Synchronizes I/O mem access to base. */
spinlock_t lock;
struct completion cmd_complete;
- u32 (*get_clk_reg_val)(struct device *dev,
- u32 divisor);
+ struct aspeed_i2c_config *config;
unsigned long parent_clk_frequency;
u32 bus_frequency;
/* Transaction state. */
@@ -164,6 +186,11 @@ struct aspeed_i2c_bus {
int master_xfer_result;
/* Multi-master */
bool multi_master;
+ /* Buffer mode */
+ void __iomem *buf_base;
+ u8 buf_offset;
+ u8 buf_page;
+ size_t buf_size;
#if IS_ENABLED(CONFIG_I2C_SLAVE)
struct i2c_client *slave;
enum aspeed_i2c_slave_state slave_state;
@@ -241,6 +268,77 @@ static int aspeed_i2c_recover_bus(struct aspeed_i2c_bus *bus)
}
#if IS_ENABLED(CONFIG_I2C_SLAVE)
+static inline void
+aspeed_i2c_slave_handle_rx_done(struct aspeed_i2c_bus *bus, u32 irq_status,
+ u8 *value)
+{
+ 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;
+}
+
+static inline void
+aspeed_i2c_slave_handle_normal_stop(struct aspeed_i2c_bus *bus, u32 irq_status,
+ u8 *value)
+{
+ int i, len;
+
+ 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(bus->slave,
+ I2C_SLAVE_WRITE_RECEIVED,
+ value);
+ }
+ }
+ }
+}
+
+static inline void
+aspeed_i2c_slave_handle_write_requested(struct aspeed_i2c_bus *bus, u8 *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);
+ }
+}
+
+static inline void
+aspeed_i2c_slave_handle_write_received(struct aspeed_i2c_bus *bus, u8 *value)
+{
+ int i, len;
+
+ 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(bus->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);
+ }
+}
+
static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status)
{
u32 command, irq_handled = 0;
@@ -267,7 +365,7 @@ 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;
+ aspeed_i2c_slave_handle_rx_done(bus, irq_status, &value);
/* Handle address frame. */
if (bus->slave_state == ASPEED_I2C_SLAVE_START) {
if (value & 0x1)
@@ -282,9 +380,11 @@ 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) {
+ aspeed_i2c_slave_handle_normal_stop(bus, irq_status, &value);
irq_handled |= ASPEED_I2CD_INTR_NORMAL_STOP;
bus->slave_state = ASPEED_I2C_SLAVE_STOP;
}
+
if (irq_status & ASPEED_I2CD_INTR_TX_NAK &&
bus->slave_state == ASPEED_I2C_SLAVE_READ_PROCESSED) {
irq_handled |= ASPEED_I2CD_INTR_TX_NAK;
@@ -314,9 +414,11 @@ 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);
+ aspeed_i2c_slave_handle_write_requested(bus, &value);
break;
case ASPEED_I2C_SLAVE_WRITE_RECEIVED:
i2c_slave_event(slave, I2C_SLAVE_WRITE_RECEIVED, &value);
+ aspeed_i2c_slave_handle_write_received(bus, &value);
break;
case ASPEED_I2C_SLAVE_STOP:
i2c_slave_event(slave, I2C_SLAVE_STOP, &value);
@@ -336,12 +438,76 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status)
}
#endif /* CONFIG_I2C_SLAVE */
+static inline u32
+aspeed_i2c_prepare_rx_buf(struct aspeed_i2c_bus *bus, struct i2c_msg *msg)
+{
+ u32 command = 0;
+ int len;
+
+ if (msg->len > bus->buf_size) {
+ len = bus->buf_size;
+ } else {
+ len = msg->len;
+ command |= ASPEED_I2CD_M_S_RX_CMD_LAST;
+ }
+
+ if (bus->buf_base) {
+ command |= ASPEED_I2CD_RX_BUFF_ENABLE;
+
+ 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);
+ }
+
+ return command;
+}
+
+static inline u32
+aspeed_i2c_prepare_tx_buf(struct aspeed_i2c_bus *bus, struct i2c_msg *msg)
+{
+ u8 slave_addr = i2c_8bit_addr_from_msg(msg);
+ u32 command = 0;
+ int len;
+
+ if (msg->len + 1 > bus->buf_size)
+ len = bus->buf_size;
+ else
+ len = msg->len + 1;
+
+ if (bus->buf_base) {
+ u8 wbuf[4];
+ int i;
+
+ command |= ASPEED_I2CD_TX_BUFF_ENABLE;
+
+ /*
+ * Yeah, it looks bad but byte writing on remapped I2C SRAM
+ * causes corruption 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));
+
+ 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);
+ }
+
+ bus->buf_index = len - 1;
+
+ return command;
+}
+
/* precondition: bus.lock has been acquired. */
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);
#if IS_ENABLED(CONFIG_I2C_SLAVE)
/*
@@ -360,12 +526,21 @@ 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 (!(msg->flags & I2C_M_RECV_LEN)) {
+ if (msg->len && bus->buf_base)
+ command |= aspeed_i2c_prepare_rx_buf(bus, msg);
+
+ /* Need to let the hardware know to NACK after RX. */
+ if (msg->len <= 1)
+ command |= ASPEED_I2CD_M_S_RX_CMD_LAST;
+ }
+ } else if (msg->len && bus->buf_base) {
+ command |= aspeed_i2c_prepare_tx_buf(bus, msg);
}
- writel(slave_addr, bus->base + ASPEED_I2C_BYTE_BUF_REG);
+ if (!(command & ASPEED_I2CD_TX_BUFF_ENABLE))
+ writel(i2c_8bit_addr_from_msg(msg),
+ bus->base + ASPEED_I2C_BYTE_BUF_REG);
writel(command, bus->base + ASPEED_I2C_CMD_REG);
}
@@ -400,6 +575,107 @@ static int aspeed_i2c_is_irq_error(u32 irq_status)
return 0;
}
+static inline u32
+aspeed_i2c_master_handle_tx_first(struct aspeed_i2c_bus *bus,
+ struct i2c_msg *msg)
+{
+ u32 command = 0;
+
+ if (bus->buf_base) {
+ u8 wbuf[4];
+ int len;
+ int i;
+
+ if (msg->len - bus->buf_index > bus->buf_size)
+ len = bus->buf_size;
+ else
+ len = msg->len - bus->buf_index;
+
+ 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;
+
+ /*
+ * Looks bad here again but use dword writings to avoid data
+ * corruption of byte writing on remapped I2C SRAM.
+ */
+ 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));
+
+ 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);
+
+ bus->buf_index += len;
+ } else {
+ writel(msg->buf[bus->buf_index++],
+ bus->base + ASPEED_I2C_BYTE_BUF_REG);
+ }
+
+ return command;
+}
+
+static inline void
+aspeed_i2c_master_handle_rx(struct aspeed_i2c_bus *bus, struct i2c_msg *msg)
+{
+ u8 recv_byte;
+ int len;
+
+ if (bus->buf_base) {
+ 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;
+ }
+}
+
+static inline u32
+aspeed_i2c_master_handle_rx_next(struct aspeed_i2c_bus *bus,
+ struct i2c_msg *msg)
+{
+ u32 command = 0;
+
+ if (bus->buf_base) {
+ int len;
+
+ 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;
+ }
+
+ command |= ASPEED_I2CD_RX_BUFF_ENABLE;
+
+ 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;
+ }
+
+ return command;
+}
+
static u32 aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus, u32 irq_status)
{
u32 irq_handled = 0, command = 0;
@@ -508,11 +784,10 @@ static u32 aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus, u32 irq_status)
fallthrough;
case ASPEED_I2C_MASTER_TX_FIRST:
if (bus->buf_index < msg->len) {
+ command = ASPEED_I2CD_M_TX_CMD;
+ command |= aspeed_i2c_master_handle_tx_first(bus, msg);
+ 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);
}
@@ -529,26 +804,26 @@ 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) {
+ recv_byte = readl(bus->base +
+ ASPEED_I2C_BYTE_BUF_REG) >> 8;
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->len = recv_byte + ((msg->flags & I2C_CLIENT_PEC) ?
+ 2 : 1);
msg->flags &= ~I2C_M_RECV_LEN;
+ } else if (msg->len) {
+ aspeed_i2c_master_handle_rx(bus, msg);
}
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;
+ command |= aspeed_i2c_master_handle_rx_next(bus, msg);
writel(command, bus->base + ASPEED_I2C_CMD_REG);
+ bus->master_state = ASPEED_I2C_MASTER_RX;
} else {
aspeed_i2c_next_msg_or_stop(bus);
}
@@ -887,7 +1162,7 @@ static int aspeed_i2c_init_clk(struct aspeed_i2c_bus *bus)
clk_reg_val &= (ASPEED_I2CD_TIME_TBUF_MASK |
ASPEED_I2CD_TIME_THDSTA_MASK |
ASPEED_I2CD_TIME_TACST_MASK);
- clk_reg_val |= bus->get_clk_reg_val(bus->dev, divisor);
+ clk_reg_val |= bus->config->get_clk_reg_val(bus->dev, divisor);
writel(clk_reg_val, bus->base + ASPEED_I2C_AC_TIMING_REG1);
writel(ASPEED_NO_TIMEOUT_CTRL, bus->base + ASPEED_I2C_AC_TIMING_REG2);
@@ -908,6 +1183,9 @@ 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
@@ -948,40 +1226,129 @@ static int aspeed_i2c_reset(struct aspeed_i2c_bus *bus)
return ret;
}
+static int aspeed_i2c_24xx_enable_sram(void)
+{
+ /* SRAM is enabled by default */
+
+ return 0;
+}
+
+static int aspeed_i2c_25xx_enable_sram(void)
+{
+ struct regmap *gr_regmap;
+ int ret;
+
+ 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);
+
+ return ret;
+}
+
+static int aspeed_i2c_24xx_set_buf_xfer_mode(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct aspeed_i2c_bus *bus = platform_get_drvdata(pdev);
+ 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);
+ bus->buf_page = ((res->start >> 8) & GENMASK(3, 0)) - 8;
+ bus->buf_offset = (res->start >> 2) &
+ ASPEED_I2CD_BUF_OFFSET_MASK;
+ }
+
+ return bus->buf_size ? 0 : -EINVAL;
+}
+
+static int aspeed_i2c_25xx_set_buf_xfer_mode(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct aspeed_i2c_bus *bus = platform_get_drvdata(pdev);
+ 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);
+
+ return bus->buf_size ? 0 : -EINVAL;
+}
+
+static const struct aspeed_i2c_config ast24xx_config = {
+ .get_clk_reg_val = aspeed_i2c_24xx_get_clk_reg_val,
+ .enable_sram = aspeed_i2c_24xx_enable_sram,
+ .set_buf_xfer_mode = aspeed_i2c_24xx_set_buf_xfer_mode,
+};
+
+static const struct aspeed_i2c_config ast25xx_config = {
+ .get_clk_reg_val = aspeed_i2c_25xx_get_clk_reg_val,
+ .enable_sram = aspeed_i2c_25xx_enable_sram,
+ .set_buf_xfer_mode = aspeed_i2c_25xx_set_buf_xfer_mode,
+};
+
+static const struct aspeed_i2c_config ast26xx_config = {
+ .get_clk_reg_val = aspeed_i2c_25xx_get_clk_reg_val,
+ .enable_sram = aspeed_i2c_24xx_enable_sram,
+ .set_buf_xfer_mode = aspeed_i2c_25xx_set_buf_xfer_mode,
+};
+
static const struct of_device_id aspeed_i2c_bus_of_table[] = {
- {
- .compatible = "aspeed,ast2400-i2c-bus",
- .data = aspeed_i2c_24xx_get_clk_reg_val,
- },
- {
- .compatible = "aspeed,ast2500-i2c-bus",
- .data = aspeed_i2c_25xx_get_clk_reg_val,
- },
- {
- .compatible = "aspeed,ast2600-i2c-bus",
- .data = aspeed_i2c_25xx_get_clk_reg_val,
- },
- { },
+ { .compatible = "aspeed,ast2400-i2c-bus", .data = &ast24xx_config, },
+ { .compatible = "aspeed,ast2500-i2c-bus", .data = &ast25xx_config, },
+ { .compatible = "aspeed,ast2600-i2c-bus", .data = &ast26xx_config, },
+ {}
};
MODULE_DEVICE_TABLE(of, aspeed_i2c_bus_of_table);
+static void aspeed_i2c_set_xfer_mode(struct aspeed_i2c_bus *bus)
+{
+ struct platform_device *pdev = to_platform_device(bus->dev);
+ const char *mode;
+ int ret;
+
+ mode = of_get_property(pdev->dev.of_node, "aspeed,i2c-xfer-mode", NULL);
+ if (!mode || strncasecmp(mode, "byte", 4) == 0)
+ return;
+
+ ret = bus->config->enable_sram();
+ if (!ret && !strncasecmp(mode, "buf", 3))
+ ret = bus->config->set_buf_xfer_mode(bus->dev);
+
+ if (ret)
+ dev_dbg(&pdev->dev, "Use default (byte) xfer mode\n");
+}
+
static int aspeed_i2c_probe_bus(struct platform_device *pdev)
{
const struct of_device_id *match;
struct aspeed_i2c_bus *bus;
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);
+ bus->dev = &pdev->dev;
+ platform_set_drvdata(pdev, bus);
+
parent_clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(parent_clk))
return PTR_ERR(parent_clk);
@@ -1007,10 +1374,11 @@ static int aspeed_i2c_probe_bus(struct platform_device *pdev)
match = of_match_node(aspeed_i2c_bus_of_table, pdev->dev.of_node);
if (!match)
- bus->get_clk_reg_val = aspeed_i2c_24xx_get_clk_reg_val;
- else
- bus->get_clk_reg_val = (u32 (*)(struct device *, u32))
- match->data;
+ return -EINVAL;
+
+ bus->config = (struct aspeed_i2c_config *)match->data;
+
+ aspeed_i2c_set_xfer_mode(bus);
/* Initialize the I2C adapter */
spin_lock_init(&bus->lock);
@@ -1023,8 +1391,6 @@ static int aspeed_i2c_probe_bus(struct platform_device *pdev)
strlcpy(bus->adap.name, pdev->name, sizeof(bus->adap.name));
i2c_set_adapdata(&bus->adap, bus);
- bus->dev = &pdev->dev;
-
/* Clean up any left over interrupt state. */
writel(0, bus->base + ASPEED_I2C_INTR_CTRL_REG);
writel(0xffffffff, bus->base + ASPEED_I2C_INTR_STS_REG);
@@ -1046,10 +1412,8 @@ static int aspeed_i2c_probe_bus(struct platform_device *pdev)
if (ret < 0)
return ret;
- 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 ? "buf" : "byte", irq);
return 0;
}
--
2.17.1
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