diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index 75d6ab177055efa2119635eb56845388ac3a0848..7379043711dfa89455abd65bce74ac08707073f9 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -237,12 +237,16 @@ static void i2c_davinci_calc_clk_dividers(struct davinci_i2c_dev *dev)
/*
* It's not always possible to have 1 to 2 ratio when d=7, so fall back
* to minimal possible clkh in this case.
+ *
+ * Note:
+ * CLKH is not allowed to be 0, in this case I2C clock is not generated
+ * at all
*/
- if (clk >= clkl + d) {
+ if (clk > clkl + d) {
clkh = clk - clkl - d;
clkl -= d;
} else {
- clkh = 0;
+ clkh = 1;
clkl = clk - (d << 1);
}
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index 0207e194f84bb4e667d4ebec548987f40caffdd1..498c5e89164988beb8d82e5f4bc53aac82b137ac 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -368,6 +368,7 @@ static int i2c_imx_dma_xfer(struct imx_i2c_struct *i2c_imx,
goto err_desc;
}
+ reinit_completion(&dma->cmd_complete);
txdesc->callback = i2c_imx_dma_callback;
txdesc->callback_param = i2c_imx;
if (dma_submit_error(dmaengine_submit(txdesc))) {
@@ -622,7 +623,6 @@ static int i2c_imx_dma_write(struct imx_i2c_struct *i2c_imx,
* The first byte must be transmitted by the CPU.
*/
imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR);
- reinit_completion(&i2c_imx->dma->cmd_complete);
time_left = wait_for_completion_timeout(
&i2c_imx->dma->cmd_complete,
msecs_to_jiffies(DMA_TIMEOUT));
@@ -681,7 +681,6 @@ static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx,
if (result)
return result;
- reinit_completion(&i2c_imx->dma->cmd_complete);
time_left = wait_for_completion_timeout(
&i2c_imx->dma->cmd_complete,
msecs_to_jiffies(DMA_TIMEOUT));
@@ -1010,7 +1009,7 @@ static int i2c_imx_init_recovery_info(struct imx_i2c_struct *i2c_imx,
i2c_imx->pinctrl_pins_gpio = pinctrl_lookup_state(i2c_imx->pinctrl,
"gpio");
rinfo->sda_gpiod = devm_gpiod_get(&pdev->dev, "sda", GPIOD_IN);
- rinfo->scl_gpiod = devm_gpiod_get(&pdev->dev, "scl", GPIOD_OUT_HIGH);
+ rinfo->scl_gpiod = devm_gpiod_get(&pdev->dev, "scl", GPIOD_OUT_HIGH_OPEN_DRAIN);
if (PTR_ERR(rinfo->sda_gpiod) == -EPROBE_DEFER ||
PTR_ERR(rinfo->scl_gpiod) == -EPROBE_DEFER) {
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index 5e310efd94464897d9db7becf89294a8b2adc4f6..3c1c817f6968e43fdafd73ff6f53d381c2528b96 100644
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -32,6 +32,7 @@
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
+#include <linux/reset.h>
#include <linux/slab.h>
/* register offsets */
@@ -111,8 +112,9 @@
#define ID_ARBLOST (1 << 3)
#define ID_NACK (1 << 4)
/* persistent flags */
+#define ID_P_NO_RXDMA (1 << 30) /* HW forbids RXDMA sometimes */
#define ID_P_PM_BLOCKED (1 << 31)
-#define ID_P_MASK ID_P_PM_BLOCKED
+#define ID_P_MASK (ID_P_PM_BLOCKED | ID_P_NO_RXDMA)
enum rcar_i2c_type {
I2C_RCAR_GEN1,
@@ -141,6 +143,8 @@ struct rcar_i2c_priv {
struct dma_chan *dma_rx;
struct scatterlist sg;
enum dma_data_direction dma_direction;
+
+ struct reset_control *rstc;
};
#define rcar_i2c_priv_to_dev(p) ((p)->adap.dev.parent)
@@ -370,6 +374,11 @@ static void rcar_i2c_dma_unmap(struct rcar_i2c_priv *priv)
dma_unmap_single(chan->device->dev, sg_dma_address(&priv->sg),
sg_dma_len(&priv->sg), priv->dma_direction);
+ /* Gen3 can only do one RXDMA per transfer and we just completed it */
+ if (priv->devtype == I2C_RCAR_GEN3 &&
+ priv->dma_direction == DMA_FROM_DEVICE)
+ priv->flags |= ID_P_NO_RXDMA;
+
priv->dma_direction = DMA_NONE;
}
@@ -407,8 +416,9 @@ static void rcar_i2c_dma(struct rcar_i2c_priv *priv)
unsigned char *buf;
int len;
- /* Do not use DMA if it's not available or for messages < 8 bytes */
- if (IS_ERR(chan) || msg->len < 8 || !(msg->flags & I2C_M_DMA_SAFE))
+ /* Do various checks to see if DMA is feasible at all */
+ if (IS_ERR(chan) || msg->len < 8 || !(msg->flags & I2C_M_DMA_SAFE) ||
+ (read && priv->flags & ID_P_NO_RXDMA))
return;
if (read) {
@@ -739,6 +749,25 @@ static void rcar_i2c_release_dma(struct rcar_i2c_priv *priv)
}
}
+/* I2C is a special case, we need to poll the status of a reset */
+static int rcar_i2c_do_reset(struct rcar_i2c_priv *priv)
+{
+ int i, ret;
+
+ ret = reset_control_reset(priv->rstc);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < LOOP_TIMEOUT; i++) {
+ ret = reset_control_status(priv->rstc);
+ if (ret == 0)
+ return 0;
+ udelay(1);
+ }
+
+ return -ETIMEDOUT;
+}
+
static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
struct i2c_msg *msgs,
int num)
@@ -750,6 +779,16 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
pm_runtime_get_sync(dev);
+ /* Gen3 needs a reset before allowing RXDMA once */
+ if (priv->devtype == I2C_RCAR_GEN3) {
+ priv->flags |= ID_P_NO_RXDMA;
+ if (!IS_ERR(priv->rstc)) {
+ ret = rcar_i2c_do_reset(priv);
+ if (ret == 0)
+ priv->flags &= ~ID_P_NO_RXDMA;
+ }
+ }
+
rcar_i2c_init(priv);
ret = rcar_i2c_bus_barrier(priv);
@@ -920,6 +959,15 @@ static int rcar_i2c_probe(struct platform_device *pdev)
if (ret < 0)
goto out_pm_put;
+ if (priv->devtype == I2C_RCAR_GEN3) {
+ priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
+ if (!IS_ERR(priv->rstc)) {
+ ret = reset_control_status(priv->rstc);
+ if (ret < 0)
+ priv->rstc = ERR_PTR(-ENOTSUPP);
+ }
+ }
+
/* Stay always active when multi-master to keep arbitration working */
if (of_property_read_bool(dev->of_node, "multi-master"))
priv->flags |= ID_P_PM_BLOCKED;