Useful for recovering busses. This needs additional device tree properties
describing the sda/scl gpios. The corresponding linux patch with the binding
description is currently under review.
Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
---
drivers/i2c/busses/i2c-imx.c | 67 ++++++++++++++++++++++++++++++++++++++++----
1 file changed, 62 insertions(+), 5 deletions(-)
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index 4cd03e1..7df4a26 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -35,11 +35,14 @@
#include <driver.h>
#include <init.h>
#include <of.h>
+#include <gpio.h>
#include <malloc.h>
#include <types.h>
#include <xfuncs.h>
#include <linux/clk.h>
#include <linux/err.h>
+#include <pinctrl.h>
+#include <of_gpio.h>
#include <io.h>
#include <i2c/i2c.h>
@@ -108,6 +111,7 @@ struct fsl_i2c_struct {
int stopped;
unsigned int ifdr; /* FSL_I2C_IFDR */
unsigned int dfsrr; /* FSL_I2C_DFSRR */
+ struct i2c_bus_recovery_info rinfo;
};
#define to_fsl_i2c_struct(a) container_of(a, struct fsl_i2c_struct, adapter)
@@ -232,8 +236,12 @@ static int i2c_fsl_start(struct i2c_adapter *adapter)
writeb(temp, base + FSL_I2C_I2CR);
result = i2c_fsl_bus_busy(adapter, 1);
- if (result)
- return result;
+ if (result) {
+ result = i2c_recover_bus(&i2c_fsl->adapter);
+ if (result)
+ return result;
+ return -EAGAIN;
+ }
i2c_fsl->stopped = 0;
@@ -494,9 +502,14 @@ static int i2c_fsl_xfer(struct i2c_adapter *adapter,
int result;
/* Start I2C transfer */
- result = i2c_fsl_start(adapter);
- if (result)
- goto fail0;
+ for (i = 0; i < 3; i++) {
+ result = i2c_fsl_start(adapter);
+ if (!result)
+ break;
+ if (result == -EAGAIN)
+ continue;
+ return result;
+ }
/* read/write data */
for (i = 0; i < num; i++) {
@@ -527,6 +540,48 @@ fail0:
return (result < 0) ? result : num;
}
+static void i2c_fsl_prepare_recovery(struct i2c_adapter *adapter)
+{
+ int ret;
+
+ ret = pinctrl_select_state(adapter->dev.parent, "gpio");
+ if (ret)
+ dev_err(adapter->dev.parent, "pinctrl failed: %s\n", strerror(-ret));
+}
+static void i2c_fsl_unprepare_recovery(struct i2c_adapter *adapter)
+{
+ int ret;
+
+ ret = pinctrl_select_state(adapter->dev.parent, "default");
+ if (ret)
+ dev_err(adapter->dev.parent, "pinctrl failed: %s\n", strerror(-ret));
+}
+
+static void i2c_fsl_init_recovery(struct fsl_i2c_struct *i2c_fsl, struct device_d *dev)
+{
+ if (!dev->device_node)
+ return;
+
+ i2c_fsl->rinfo.sda_gpio = of_get_named_gpio_flags(dev->device_node,
+ "sda-gpios", 0, NULL);
+ i2c_fsl->rinfo.scl_gpio = of_get_named_gpio_flags(dev->device_node,
+ "scl-gpios", 0, NULL);
+
+ if (!gpio_is_valid(i2c_fsl->rinfo.sda_gpio) ||
+ !gpio_is_valid(i2c_fsl->rinfo.scl_gpio))
+ return;
+
+ i2c_fsl->rinfo.get_scl = i2c_get_scl_gpio_value;
+ i2c_fsl->rinfo.get_sda = i2c_get_sda_gpio_value;
+ i2c_fsl->rinfo.set_scl = i2c_set_scl_gpio_value;
+ i2c_fsl->rinfo.prepare_recovery = i2c_fsl_prepare_recovery;
+ i2c_fsl->rinfo.unprepare_recovery = i2c_fsl_unprepare_recovery;
+ i2c_fsl->rinfo.recover_bus = i2c_generic_gpio_recovery;
+ i2c_fsl->adapter.bus_recovery_info = &i2c_fsl->rinfo;
+
+ dev_dbg(dev, "initialized recovery info\n");
+}
+
static int __init i2c_fsl_probe(struct device_d *pdev)
{
struct fsl_i2c_struct *i2c_fsl;
@@ -555,6 +610,8 @@ static int __init i2c_fsl_probe(struct device_d *pdev)
goto fail;
}
+ i2c_fsl_init_recovery(i2c_fsl, pdev);
+
i2c_fsl->dfsrr = -1;
/* Set up clock divider */
--
2.5.0
_______________________________________________
barebox mailing list
barebox@xxxxxxxxxxxxxxxxxxx
http://lists.infradead.org/mailman/listinfo/barebox
