Revert "i2c: designware: Add support for bus clear feature"

This reverts commit 24cb07b.
raspberrypi · Nov 18, 2024 · a651f95 · a651f95
1 parent b4472d0
commit a651f95
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Showing 3 changed files with 1 addition and 38 deletions.
diff --git a/drivers/i2c/busses/i2c-designware-common.c b/drivers/i2c/busses/i2c-designware-common.c
@@ -57,8 +57,6 @@ static char *abort_sources[] = {
 		"slave lost the bus while transmitting data to a remote master",
 	[ABRT_SLAVE_RD_INTX] =
 		"incorrect slave-transmitter mode configuration",
-	[ABRT_SLAVE_SDA_STUCK_AT_LOW] =
-		"SDA stuck at low",
 };
 
 static int dw_reg_read(void *context, unsigned int reg, unsigned int *val)
@@ -609,16 +607,8 @@ int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev)
 int i2c_dw_handle_tx_abort(struct dw_i2c_dev *dev)
 {
 	unsigned long abort_source = dev->abort_source;
-	unsigned int reg;
 	int i;
 
-	if (abort_source & DW_IC_TX_ABRT_SLAVE_SDA_STUCK_AT_LOW) {
-		regmap_write(dev->map, DW_IC_ENABLE,
-			     DW_IC_ENABLE_ENABLE | DW_IC_ENABLE_BUS_RECOVERY);
-		regmap_read_poll_timeout(dev->map, DW_IC_ENABLE, reg,
-					 !(reg & DW_IC_ENABLE_BUS_RECOVERY),
-					 1100, 200000);
-	}
 	if (abort_source & DW_IC_TX_ABRT_NOACK) {
 		for_each_set_bit(i, &abort_source, ARRAY_SIZE(abort_sources))
 			dev_dbg(dev->dev,
@@ -633,8 +623,6 @@ int i2c_dw_handle_tx_abort(struct dw_i2c_dev *dev)
 		return -EAGAIN;
 	else if (abort_source & DW_IC_TX_ABRT_GCALL_READ)
 		return -EINVAL; /* wrong msgs[] data */
-	else if (abort_source & DW_IC_TX_ABRT_SLAVE_SDA_STUCK_AT_LOW)
-		return -EREMOTEIO;
 	else
 		return -EIO;
 }

diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
@@ -79,12 +79,9 @@
 #define DW_IC_TX_ABRT_SOURCE			0x80
 #define DW_IC_ENABLE_STATUS			0x9c
 #define DW_IC_CLR_RESTART_DET			0xa8
-#define DW_IC_SCL_STUCK_AT_LOW_TIMEOUT		0xac
-#define DW_IC_SDA_STUCK_AT_LOW_TIMEOUT		0xb0
 #define DW_IC_COMP_PARAM_1			0xf4
 #define DW_IC_COMP_VERSION			0xf8
 #define DW_IC_SDA_HOLD_MIN_VERS			0x3131312A /* "111*" == v1.11* */
-#define DW_IC_BUS_CLEAR_MIN_VERS		0x3230302A /* "200*" == v2.00* */
 #define DW_IC_COMP_TYPE				0xfc
 #define DW_IC_COMP_TYPE_VALUE			0x44570140 /* "DW" + 0x0140 */
 
@@ -112,16 +109,13 @@
 						 DW_IC_INTR_RX_UNDER | \
 						 DW_IC_INTR_RD_REQ)
 
-#define DW_IC_ENABLE_ENABLE			BIT(0)
 #define DW_IC_ENABLE_ABORT			BIT(1)
-#define DW_IC_ENABLE_BUS_RECOVERY		BIT(3)
 
 #define DW_IC_STATUS_ACTIVITY			BIT(0)
 #define DW_IC_STATUS_TFE			BIT(2)
 #define DW_IC_STATUS_RFNE			BIT(3)
 #define DW_IC_STATUS_MASTER_ACTIVITY		BIT(5)
 #define DW_IC_STATUS_SLAVE_ACTIVITY		BIT(6)
-#define DW_IC_STATUS_SDA_STUCK_NOT_RECOVERED	BIT(11)
 
 #define DW_IC_SDA_HOLD_RX_SHIFT			16
 #define DW_IC_SDA_HOLD_RX_MASK			GENMASK(23, 16)
@@ -169,7 +163,6 @@
 #define ABRT_SLAVE_FLUSH_TXFIFO			13
 #define ABRT_SLAVE_ARBLOST			14
 #define ABRT_SLAVE_RD_INTX			15
-#define ABRT_SLAVE_SDA_STUCK_AT_LOW		17
 
 #define DW_IC_TX_ABRT_7B_ADDR_NOACK		BIT(ABRT_7B_ADDR_NOACK)
 #define DW_IC_TX_ABRT_10ADDR1_NOACK		BIT(ABRT_10ADDR1_NOACK)
@@ -185,7 +178,6 @@
 #define DW_IC_RX_ABRT_SLAVE_RD_INTX		BIT(ABRT_SLAVE_RD_INTX)
 #define DW_IC_RX_ABRT_SLAVE_ARBLOST		BIT(ABRT_SLAVE_ARBLOST)
 #define DW_IC_RX_ABRT_SLAVE_FLUSH_TXFIFO	BIT(ABRT_SLAVE_FLUSH_TXFIFO)
-#define DW_IC_TX_ABRT_SLAVE_SDA_STUCK_AT_LOW	BIT(ABRT_SLAVE_SDA_STUCK_AT_LOW)
 
 #define DW_IC_TX_ABRT_NOACK			(DW_IC_TX_ABRT_7B_ADDR_NOACK | \
 						 DW_IC_TX_ABRT_10ADDR1_NOACK | \

diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c
@@ -215,7 +215,6 @@ static int i2c_dw_set_timings_master(struct dw_i2c_dev *dev)
  */
 static int i2c_dw_init_master(struct dw_i2c_dev *dev)
 {
-	unsigned int timeout = 0;
 	int ret;
 
 	ret = i2c_dw_acquire_lock(dev);
@@ -239,17 +238,6 @@ static int i2c_dw_init_master(struct dw_i2c_dev *dev)
 		regmap_write(dev->map, DW_IC_HS_SCL_LCNT, dev->hs_lcnt);
 	}
 
-	if (dev->master_cfg & DW_IC_CON_BUS_CLEAR_CTRL) {
-		/* Set a sensible timeout if not already configured */
-		regmap_read(dev->map, DW_IC_SDA_STUCK_AT_LOW_TIMEOUT, &timeout);
-		if (timeout == ~0) {
-			/* Use 10ms as a timeout, which is 1000 cycles at 100kHz */
-			timeout = i2c_dw_clk_rate(dev) * 10; /* clock rate is in kHz */
-			regmap_write(dev->map, DW_IC_SDA_STUCK_AT_LOW_TIMEOUT, timeout);
-			regmap_write(dev->map, DW_IC_SCL_STUCK_AT_LOW_TIMEOUT, timeout);
-		}
-	}
-
 	/* Write SDA hold time if supported */
 	if (dev->sda_hold_time)
 		regmap_write(dev->map, DW_IC_SDA_HOLD, dev->sda_hold_time);
@@ -1086,7 +1074,6 @@ int i2c_dw_probe_master(struct dw_i2c_dev *dev)
 	struct i2c_adapter *adap = &dev->adapter;
 	unsigned long irq_flags;
 	unsigned int ic_con;
-	unsigned int id_ver;
 	int ret;
 
 	init_completion(&dev->cmd_complete);
@@ -1122,11 +1109,7 @@ int i2c_dw_probe_master(struct dw_i2c_dev *dev)
 	if (ret)
 		return ret;
 
-	ret = regmap_read(dev->map, DW_IC_COMP_VERSION, &id_ver);
-	if (ret)
-		return ret;
-
-	if (ic_con & DW_IC_CON_BUS_CLEAR_CTRL || id_ver >= DW_IC_BUS_CLEAR_MIN_VERS)
+	if (ic_con & DW_IC_CON_BUS_CLEAR_CTRL)
 		dev->master_cfg |= DW_IC_CON_BUS_CLEAR_CTRL;
 
 	ret = dev->init(dev);