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path: root/drivers/i2c/busses/i2c-imx.c
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Diffstat (limited to 'drivers/i2c/busses/i2c-imx.c')
-rw-r--r--drivers/i2c/busses/i2c-imx.c148
1 files changed, 107 insertions, 41 deletions
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index 753d2d04cd3a..4a372b78c56d 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -34,6 +34,7 @@
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
+#include <linux/iopoll.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
@@ -513,7 +514,7 @@ static void i2c_imx_clr_al_bit(unsigned int status, struct imx_i2c_struct *i2c_i
imx_i2c_write_reg(status, i2c_imx, IMX_I2C_I2SR);
}
-static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
+static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy, bool atomic)
{
unsigned long orig_jiffies = jiffies;
unsigned int temp;
@@ -542,15 +543,38 @@ static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
"<%s> I2C bus is busy\n", __func__);
return -ETIMEDOUT;
}
- schedule();
+ if (atomic)
+ udelay(100);
+ else
+ schedule();
+
}
return 0;
}
-static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx)
+static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx, bool atomic)
{
- wait_event_timeout(i2c_imx->queue, i2c_imx->i2csr & I2SR_IIF, HZ / 10);
+ if (atomic) {
+ void __iomem *addr = i2c_imx->base + (IMX_I2C_I2SR << i2c_imx->hwdata->regshift);
+ unsigned int regval;
+
+ /*
+ * The formula for the poll timeout is documented in the RM
+ * Rev.5 on page 1878:
+ * T_min = 10/F_scl
+ * Set the value hard as it is done for the non-atomic use-case.
+ * Use 10 kHz for the calculation since this is the minimum
+ * allowed SMBus frequency. Also add an offset of 100us since it
+ * turned out that the I2SR_IIF bit isn't set correctly within
+ * the minimum timeout in polling mode.
+ */
+ readb_poll_timeout_atomic(addr, regval, regval & I2SR_IIF, 5, 1000 + 100);
+ i2c_imx->i2csr = regval;
+ imx_i2c_write_reg(0, i2c_imx, IMX_I2C_I2SR);
+ } else {
+ wait_event_timeout(i2c_imx->queue, i2c_imx->i2csr & I2SR_IIF, HZ / 10);
+ }
if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) {
dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__);
@@ -639,7 +663,7 @@ static int i2c_imx_clk_notifier_call(struct notifier_block *nb,
return notifier_from_errno(ret);
}
-static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
+static int i2c_imx_start(struct imx_i2c_struct *i2c_imx, bool atomic)
{
unsigned int temp = 0;
int result;
@@ -656,23 +680,29 @@ static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
imx_i2c_write_reg(i2c_imx->hwdata->i2cr_ien_opcode, i2c_imx, IMX_I2C_I2CR);
/* Wait controller to be stable */
- usleep_range(50, 150);
+ if (atomic)
+ udelay(50);
+ else
+ usleep_range(50, 150);
/* Start I2C transaction */
temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
temp |= I2CR_MSTA;
imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
- result = i2c_imx_bus_busy(i2c_imx, 1);
+ result = i2c_imx_bus_busy(i2c_imx, 1, atomic);
if (result)
return result;
temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK;
+ if (atomic)
+ temp &= ~I2CR_IIEN; /* Disable interrupt */
+
temp &= ~I2CR_DMAEN;
imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
return result;
}
-static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
+static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx, bool atomic)
{
unsigned int temp = 0;
@@ -694,7 +724,7 @@ static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx)
}
if (!i2c_imx->stopped)
- i2c_imx_bus_busy(i2c_imx, 0);
+ i2c_imx_bus_busy(i2c_imx, 0, atomic);
/* Disable I2C controller */
temp = i2c_imx->hwdata->i2cr_ien_opcode ^ I2CR_IEN,
@@ -777,7 +807,7 @@ static int i2c_imx_dma_write(struct imx_i2c_struct *i2c_imx,
/* The last data byte must be transferred by the CPU. */
imx_i2c_write_reg(msgs->buf[msgs->len-1],
i2c_imx, IMX_I2C_I2DR);
- result = i2c_imx_trx_complete(i2c_imx);
+ result = i2c_imx_trx_complete(i2c_imx, false);
if (result)
return result;
@@ -836,7 +866,7 @@ static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx,
msgs->buf[msgs->len-2] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
/* read n byte data */
- result = i2c_imx_trx_complete(i2c_imx);
+ result = i2c_imx_trx_complete(i2c_imx, false);
if (result)
return result;
@@ -849,7 +879,7 @@ static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx,
temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
temp &= ~(I2CR_MSTA | I2CR_MTX);
imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
- i2c_imx_bus_busy(i2c_imx, 0);
+ i2c_imx_bus_busy(i2c_imx, 0, false);
} else {
/*
* For i2c master receiver repeat restart operation like:
@@ -867,7 +897,8 @@ static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx,
return 0;
}
-static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
+static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs,
+ bool atomic)
{
int i, result;
@@ -876,7 +907,7 @@ static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
/* write slave address */
imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR);
- result = i2c_imx_trx_complete(i2c_imx);
+ result = i2c_imx_trx_complete(i2c_imx, atomic);
if (result)
return result;
result = i2c_imx_acked(i2c_imx);
@@ -890,7 +921,7 @@ static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
"<%s> write byte: B%d=0x%X\n",
__func__, i, msgs->buf[i]);
imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR);
- result = i2c_imx_trx_complete(i2c_imx);
+ result = i2c_imx_trx_complete(i2c_imx, atomic);
if (result)
return result;
result = i2c_imx_acked(i2c_imx);
@@ -900,7 +931,8 @@ static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
return 0;
}
-static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, bool is_lastmsg)
+static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs,
+ bool is_lastmsg, bool atomic)
{
int i, result;
unsigned int temp;
@@ -913,7 +945,7 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, bo
/* write slave address */
imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR);
- result = i2c_imx_trx_complete(i2c_imx);
+ result = i2c_imx_trx_complete(i2c_imx, atomic);
if (result)
return result;
result = i2c_imx_acked(i2c_imx);
@@ -946,7 +978,7 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, bo
for (i = 0; i < msgs->len; i++) {
u8 len = 0;
- result = i2c_imx_trx_complete(i2c_imx);
+ result = i2c_imx_trx_complete(i2c_imx, atomic);
if (result)
return result;
/*
@@ -974,7 +1006,7 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, bo
temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
temp &= ~(I2CR_MSTA | I2CR_MTX);
imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
- i2c_imx_bus_busy(i2c_imx, 0);
+ i2c_imx_bus_busy(i2c_imx, 0, atomic);
} else {
/*
* For i2c master receiver repeat restart operation like:
@@ -1078,8 +1110,8 @@ static int i2c_imx_recovery_for_layerscape(struct imx_i2c_struct *i2c_imx)
return 0;
}
-static int i2c_imx_xfer(struct i2c_adapter *adapter,
- struct i2c_msg *msgs, int num)
+static int i2c_imx_xfer_common(struct i2c_adapter *adapter,
+ struct i2c_msg *msgs, int num, bool atomic)
{
unsigned int i, temp;
int result;
@@ -1101,15 +1133,11 @@ static int i2c_imx_xfer(struct i2c_adapter *adapter,
enable_runtime_pm = true;
}
- result = pm_runtime_get_sync(i2c_imx->adapter.dev.parent);
- if (result < 0)
- goto out;
-
/*
* workround for ERR010027: ensure that the I2C BUS is idle
* before switching to master mode and attempting a Start cycle
*/
- result = i2c_imx_bus_busy(i2c_imx, 0);
+ result = i2c_imx_bus_busy(i2c_imx, 0, atomic);
if (result) {
/* timeout */
if ((result == -ETIMEDOUT) && (i2c_imx->layerscape_bus_recover == 1))
@@ -1119,11 +1147,15 @@ static int i2c_imx_xfer(struct i2c_adapter *adapter,
}
/* Start I2C transfer */
- result = i2c_imx_start(i2c_imx);
+ result = i2c_imx_start(i2c_imx, atomic);
if (result) {
- if (i2c_imx->adapter.bus_recovery_info) {
+ /*
+ * Bus recovery uses gpiod_get_value_cansleep() which is not
+ * allowed within atomic context.
+ */
+ if (!atomic && i2c_imx->adapter.bus_recovery_info) {
i2c_recover_bus(&i2c_imx->adapter);
- result = i2c_imx_start(i2c_imx);
+ result = i2c_imx_start(i2c_imx, atomic);
}
}
@@ -1141,7 +1173,7 @@ static int i2c_imx_xfer(struct i2c_adapter *adapter,
temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
temp |= I2CR_RSTA;
imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
- result = i2c_imx_bus_busy(i2c_imx, 1);
+ result = i2c_imx_bus_busy(i2c_imx, 1, atomic);
if (result)
goto fail0;
}
@@ -1165,13 +1197,14 @@ static int i2c_imx_xfer(struct i2c_adapter *adapter,
(temp & I2SR_SRW ? 1 : 0), (temp & I2SR_IIF ? 1 : 0),
(temp & I2SR_RXAK ? 1 : 0));
#endif
- if (msgs[i].flags & I2C_M_RD)
- result = i2c_imx_read(i2c_imx, &msgs[i], is_lastmsg);
- else {
- if (i2c_imx->dma && msgs[i].len >= DMA_THRESHOLD)
+ if (msgs[i].flags & I2C_M_RD) {
+ result = i2c_imx_read(i2c_imx, &msgs[i], is_lastmsg, atomic);
+ } else {
+ if (!atomic &&
+ i2c_imx->dma && msgs[i].len >= DMA_THRESHOLD)
result = i2c_imx_dma_write(i2c_imx, &msgs[i]);
else
- result = i2c_imx_write(i2c_imx, &msgs[i]);
+ result = i2c_imx_write(i2c_imx, &msgs[i], atomic);
}
if (result)
goto fail0;
@@ -1179,10 +1212,7 @@ static int i2c_imx_xfer(struct i2c_adapter *adapter,
fail0:
/* Stop I2C transfer */
- i2c_imx_stop(i2c_imx);
-
- pm_runtime_mark_last_busy(i2c_imx->adapter.dev.parent);
- pm_runtime_put_autosuspend(i2c_imx->adapter.dev.parent);
+ i2c_imx_stop(i2c_imx, atomic);
out:
if (enable_runtime_pm)
@@ -1194,6 +1224,41 @@ out:
return (result < 0) ? result : num;
}
+static int i2c_imx_xfer(struct i2c_adapter *adapter,
+ struct i2c_msg *msgs, int num)
+{
+ struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);
+ int result;
+
+ result = pm_runtime_get_sync(i2c_imx->adapter.dev.parent);
+ if (result < 0)
+ return result;
+
+ result = i2c_imx_xfer_common(adapter, msgs, num, false);
+
+ pm_runtime_mark_last_busy(i2c_imx->adapter.dev.parent);
+ pm_runtime_put_autosuspend(i2c_imx->adapter.dev.parent);
+
+ return result;
+}
+
+static int i2c_imx_xfer_atomic(struct i2c_adapter *adapter,
+ struct i2c_msg *msgs, int num)
+{
+ struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(adapter);
+ int result;
+
+ result = clk_enable(i2c_imx->clk);
+ if (result)
+ return result;
+
+ result = i2c_imx_xfer_common(adapter, msgs, num, true);
+
+ clk_disable(i2c_imx->clk);
+
+ return result;
+}
+
static void i2c_imx_prepare_recovery(struct i2c_adapter *adap)
{
struct imx_i2c_struct *i2c_imx;
@@ -1442,8 +1507,9 @@ static int i2c_imx_unreg_slave(struct i2c_client *client)
#endif
static const struct i2c_algorithm i2c_imx_algo = {
- .master_xfer = i2c_imx_xfer,
- .functionality = i2c_imx_func,
+ .master_xfer = i2c_imx_xfer,
+ .master_xfer_atomic = i2c_imx_xfer_atomic,
+ .functionality = i2c_imx_func,
#if IS_ENABLED(CONFIG_I2C_SLAVE)
.reg_slave = i2c_imx_reg_slave,
.unreg_slave = i2c_imx_unreg_slave,
generated by cgit v1.2.3 (git 2.0.4) at 2024-04-16 11:01:44 +0000