Tegra20 i2c controller does not support the continue transfer
which implements the I2C_M_NOSTART functionality of i2c
protocol mangling.
Removing the I2C_M_NOSTART functionality for Tegra20.
Signed-off-by: Laxman Dewangan <ldewangan@xxxxxxxxxx>
Reported-by: Stephen Warren <swarren@xxxxxxxxxx>
---
drivers/i2c/busses/i2c-tegra.c | 71 ++++++++++++++++++++++++++++++++--------
1 files changed, 57 insertions(+), 14 deletions(-)
diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 66eb53f..11b0c5c 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -27,6 +27,7 @@
#include <linux/slab.h>
#include <linux/i2c-tegra.h>
#include <linux/of_i2c.h>
+#include <linux/of_device.h>
#include <linux/module.h>
#include <asm/unaligned.h>
@@ -114,6 +115,15 @@ enum msg_end_type {
};
/**
+ * struct tegra_i2c_hw_feature : Different HW support on Tegra
+ * @has_continue_xfer_support: Continue transfer supports.
+ */
+
+struct tegra_i2c_hw_feature {
+ bool has_continue_xfer_support;
+};
+
+/**
* struct tegra_i2c_dev - per device i2c context
* @dev: device reference for power management
* @adapter: core i2c layer adapter information
@@ -148,6 +158,7 @@ struct tegra_i2c_dev {
int msg_read;
unsigned long bus_clk_rate;
bool is_suspended;
+ bool has_continue_xfer_support;
};
static void dvc_writel(struct tegra_i2c_dev *i2c_dev, u32 val, unsigned long reg)
@@ -563,6 +574,16 @@ static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
if (i2c_dev->is_suspended)
return -EBUSY;
+ /* Support I2C_M_NOSTART only if HW support continue xfer. */
+ for (i = 0; i < num - 1; i++) {
+ if ((msgs[i + 1].flags & I2C_M_NOSTART) &&
+ !i2c_dev->has_continue_xfer_support) {
+ dev_err(i2c_dev->dev,
+ "mesg %d have illegal flag\n", i + 1);
+ return -EINVAL;
+ }
+ }
+
clk_prepare_enable(i2c_dev->clk);
for (i = 0; i < num; i++) {
enum msg_end_type end_type = MSG_END_STOP;
@@ -582,8 +603,13 @@ static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
static u32 tegra_i2c_func(struct i2c_adapter *adap)
{
- return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR |
- I2C_FUNC_PROTOCOL_MANGLING | I2C_FUNC_NOSTART;
+ struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
+ u32 ret = I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_10BIT_ADDR |
+ I2C_FUNC_PROTOCOL_MANGLING;
+
+ if (i2c_dev->has_continue_xfer_support)
+ ret |= I2C_FUNC_NOSTART;
+ return ret;
}
static const struct i2c_algorithm tegra_i2c_algo = {
@@ -591,6 +617,25 @@ static const struct i2c_algorithm tegra_i2c_algo = {
.functionality = tegra_i2c_func,
};
+static struct tegra_i2c_hw_feature tegra20_i2c_hw = {
+ .has_continue_xfer_support = false,
+};
+
+static struct tegra_i2c_hw_feature tegra30_i2c_hw = {
+ .has_continue_xfer_support = true,
+};
+
+#if defined(CONFIG_OF)
+/* Match table for of_platform binding */
+static const struct of_device_id tegra_i2c_of_match[] __devinitconst = {
+ { .compatible = "nvidia,tegra30-i2c", .data = &tegra30_i2c_hw, },
+ { .compatible = "nvidia,tegra20-i2c", .data = &tegra20_i2c_hw, },
+ { .compatible = "nvidia,tegra20-i2c-dvc", .data = &tegra20_i2c_hw, },
+ {},
+};
+MODULE_DEVICE_TABLE(of, tegra_i2c_of_match);
+#endif
+
static int __devinit tegra_i2c_probe(struct platform_device *pdev)
{
struct tegra_i2c_dev *i2c_dev;
@@ -600,6 +645,7 @@ static int __devinit tegra_i2c_probe(struct platform_device *pdev)
struct clk *i2c_clk;
const unsigned int *prop;
void __iomem *base;
+ const struct tegra_i2c_hw_feature *hw = &tegra20_i2c_hw;
int irq;
int ret = 0;
@@ -659,11 +705,18 @@ static int __devinit tegra_i2c_probe(struct platform_device *pdev)
i2c_dev->bus_clk_rate = be32_to_cpup(prop);
}
- if (pdev->dev.of_node)
+ if (pdev->dev.of_node) {
+ const struct of_device_id *match;
+ match = of_match_device(of_match_ptr(tegra_i2c_of_match),
+ &pdev->dev);
+ hw = match->data;
i2c_dev->is_dvc = of_device_is_compatible(pdev->dev.of_node,
"nvidia,tegra20-i2c-dvc");
- else if (pdev->id == 3)
+ } else if (pdev->id == 3) {
i2c_dev->is_dvc = 1;
+ }
+
+ i2c_dev->has_continue_xfer_support = hw->has_continue_xfer_support;
init_completion(&i2c_dev->msg_complete);
platform_set_drvdata(pdev, i2c_dev);
@@ -751,16 +804,6 @@ static SIMPLE_DEV_PM_OPS(tegra_i2c_pm, tegra_i2c_suspend, tegra_i2c_resume);
#define TEGRA_I2C_PM NULL
#endif
-#if defined(CONFIG_OF)
-/* Match table for of_platform binding */
-static const struct of_device_id tegra_i2c_of_match[] __devinitconst = {
- { .compatible = "nvidia,tegra20-i2c", },
- { .compatible = "nvidia,tegra20-i2c-dvc", },
- {},
-};
-MODULE_DEVICE_TABLE(of, tegra_i2c_of_match);
-#endif
-
static struct platform_driver tegra_i2c_driver = {
.probe = tegra_i2c_probe,
.remove = __devexit_p(tegra_i2c_remove),
--
1.7.1.1
--
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