The I2C pins on the SoCFPGA platforms do not go through a GPIO module,
thus cannot be recovered by the default method of by doing a GPIO access.
Only a reset of the I2C IP block can a recovery be successful.
The assignment of the recover_bus needs to get done before the call to
devm_gpiod_get_optional(), otherwise, the assignment is not taking place
because of an error after returning from devm_gpiod_get_optional().
Signed-off-by: Dinh Nguyen <[email protected]>
---
v3: simplify the function
update commit message
v2: remove change to MODEL_MASK
s/i2c_custom_scl_recovery/i2c_socfpga_scl_recovery
---
drivers/i2c/busses/i2c-designware-core.h | 1 +
drivers/i2c/busses/i2c-designware-master.c | 12 ++++++++++++
drivers/i2c/busses/i2c-designware-platdrv.c | 1 +
3 files changed, 14 insertions(+)
diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
index 70b80e710990..7b22ec1d6a96 100644
--- a/drivers/i2c/busses/i2c-designware-core.h
+++ b/drivers/i2c/busses/i2c-designware-core.h
@@ -303,6 +303,7 @@ struct dw_i2c_dev {
#define MODEL_MSCC_OCELOT BIT(8)
#define MODEL_BAIKAL_BT1 BIT(9)
#define MODEL_AMD_NAVI_GPU BIT(10)
+#define MODEL_SOCFPGA BIT(11)
#define MODEL_MASK GENMASK(11, 8)
/*
diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c
index 44a94b225ed8..502820b812a5 100644
--- a/drivers/i2c/busses/i2c-designware-master.c
+++ b/drivers/i2c/busses/i2c-designware-master.c
@@ -813,12 +813,24 @@ static void i2c_dw_unprepare_recovery(struct i2c_adapter *adap)
i2c_dw_init_master(dev);
}
+static int i2c_socfpga_scl_recovery(struct i2c_adapter *adap)
+{
+ i2c_dw_prepare_recovery(adap);
+ i2c_dw_unprepare_recovery(adap);
+ return 0;
+}
+
static int i2c_dw_init_recovery_info(struct dw_i2c_dev *dev)
{
struct i2c_bus_recovery_info *rinfo = &dev->rinfo;
struct i2c_adapter *adap = &dev->adapter;
struct gpio_desc *gpio;
+ if ((dev->flags & MODEL_MASK) == MODEL_SOCFPGA) {
+ rinfo->recover_bus = i2c_socfpga_scl_recovery;
+ adap->bus_recovery_info = rinfo;
+ }
+
gpio = devm_gpiod_get_optional(dev->dev, "scl", GPIOD_OUT_HIGH);
if (IS_ERR_OR_NULL(gpio))
return PTR_ERR_OR_ZERO(gpio);
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index 70ade5306e45..b33e015e6732 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -153,6 +153,7 @@ static const struct of_device_id dw_i2c_of_match[] = {
{ .compatible = "snps,designware-i2c", },
{ .compatible = "mscc,ocelot-i2c", .data = (void *)MODEL_MSCC_OCELOT },
{ .compatible = "baikal,bt1-sys-i2c", .data = (void *)MODEL_BAIKAL_BT1 },
+ { .compatible = "intel,socfpga-i2c", .data = (void *)MODEL_SOCFPGA },
{},
};
MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
--
2.25.1
On Mon, Jun 13, 2022 at 04:00:31PM -0500, Dinh Nguyen wrote:
> The I2C pins on the SoCFPGA platforms do not go through a GPIO module,
> thus cannot be recovered by the default method of by doing a GPIO access.
> Only a reset of the I2C IP block can a recovery be successful.
>
> The assignment of the recover_bus needs to get done before the call to
> devm_gpiod_get_optional(), otherwise, the assignment is not taking place
> because of an error after returning from devm_gpiod_get_optional().
Thanks for an update!
My comments below.
...
> +static int i2c_socfpga_scl_recovery(struct i2c_adapter *adap)
> +{
> + i2c_dw_prepare_recovery(adap);
> + i2c_dw_unprepare_recovery(adap);
Can we use
struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
bri->prepare_recovery(adap);
bri->unprepare_recovery(adap);
> + return 0;
> +}
instead and...
...
> static int i2c_dw_init_recovery_info(struct dw_i2c_dev *dev)
> {
> struct i2c_bus_recovery_info *rinfo = &dev->rinfo;
> struct i2c_adapter *adap = &dev->adapter;
> struct gpio_desc *gpio;
>
> + if ((dev->flags & MODEL_MASK) == MODEL_SOCFPGA) {
> + rinfo->recover_bus = i2c_socfpga_scl_recovery;
> + adap->bus_recovery_info = rinfo;
> + }
> +
> gpio = devm_gpiod_get_optional(dev->dev, "scl", GPIOD_OUT_HIGH);
> if (IS_ERR_OR_NULL(gpio))
> return PTR_ERR_OR_ZERO(gpio);
...this one to be transformed like (in a preparatory patch and in this one):
static int i2c_dw_init_socfpga_recovery_info(struct dw_i2c_dev *dev,
struct i2c_bus_recovery_info *rinfo)
{
rinfo->recover_bus = i2c_socfpga_scl_recovery;
return 0;
}
static int i2c_dw_init_generic_recovery_info(struct dw_i2c_dev *dev,
struct i2c_bus_recovery_info *rinfo)
{
struct i2c_adapter *adap = &dev->adapter;
struct gpio_desc *gpio;
gpio = devm_gpiod_get_optional(dev->dev, "scl", GPIOD_OUT_HIGH);
if (IS_ERR_OR_NULL(gpio))
return PTR_ERR_OR_ZERO(gpio);
rinfo->scl_gpiod = gpio;
gpio = devm_gpiod_get_optional(dev->dev, "sda", GPIOD_IN);
if (IS_ERR(gpio))
return PTR_ERR(gpio);
rinfo->sda_gpiod = gpio;
rinfo->recover_bus = i2c_generic_scl_recovery;
dev_info(dev->dev, "running with gpio recovery mode! scl%s",
rinfo->sda_gpiod ? ",sda" : "");
return 0;
}
static int i2c_dw_init_recovery_info(struct dw_i2c_dev *dev)
{
struct i2c_bus_recovery_info *rinfo = &dev->rinfo;
struct i2c_adapter *adap = &dev->adapter;
int ret;
switch (dev->flags & MODEL_MASK) {
case MODEL_SOCFPGA:
ret = i2c_dw_init_socfpga_recovery_info(dev, rinfo);
break;
default:
ret = i2c_dw_init_generic_recovery_info(dev, rinfo);
break;
}
if (ret)
return ret;
rinfo->prepare_recovery = i2c_dw_prepare_recovery;
rinfo->unprepare_recovery = i2c_dw_unprepare_recovery;
adap->bus_recovery_info = rinfo;
return 0;
}
--
With Best Regards,
Andy Shevchenko
On Wed, Jun 15, 2022 at 01:18:55PM +0300, Andy Shevchenko wrote:
> On Mon, Jun 13, 2022 at 04:00:31PM -0500, Dinh Nguyen wrote:
The below won't fly, see my corrections below.
> static int i2c_dw_init_socfpga_recovery_info(struct dw_i2c_dev *dev,
> struct i2c_bus_recovery_info *rinfo)
> {
> rinfo->recover_bus = i2c_socfpga_scl_recovery;
> return 0;
return 1;
> }
>
> static int i2c_dw_init_generic_recovery_info(struct dw_i2c_dev *dev,
> struct i2c_bus_recovery_info *rinfo)
> {
> struct i2c_adapter *adap = &dev->adapter;
> struct gpio_desc *gpio;
>
> gpio = devm_gpiod_get_optional(dev->dev, "scl", GPIOD_OUT_HIGH);
> if (IS_ERR_OR_NULL(gpio))
> return PTR_ERR_OR_ZERO(gpio);
>
> rinfo->scl_gpiod = gpio;
>
> gpio = devm_gpiod_get_optional(dev->dev, "sda", GPIOD_IN);
> if (IS_ERR(gpio))
> return PTR_ERR(gpio);
> rinfo->sda_gpiod = gpio;
>
> rinfo->recover_bus = i2c_generic_scl_recovery;
>
> dev_info(dev->dev, "running with gpio recovery mode! scl%s",
> rinfo->sda_gpiod ? ",sda" : "");
>
> return 0;
return 1;
> }
>
> static int i2c_dw_init_recovery_info(struct dw_i2c_dev *dev)
> {
> struct i2c_bus_recovery_info *rinfo = &dev->rinfo;
> struct i2c_adapter *adap = &dev->adapter;
> int ret;
>
> switch (dev->flags & MODEL_MASK) {
> case MODEL_SOCFPGA:
> ret = i2c_dw_init_socfpga_recovery_info(dev, rinfo);
> break;
> default:
> ret = i2c_dw_init_generic_recovery_info(dev, rinfo);
> break;
> }
> if (ret)
/* The recovery is optional, that's why 0 should be returned to the caller */
if (ret <= 0)
> return ret;
>
> rinfo->prepare_recovery = i2c_dw_prepare_recovery;
> rinfo->unprepare_recovery = i2c_dw_unprepare_recovery;
> adap->bus_recovery_info = rinfo;
>
> return 0;
> }
--
With Best Regards,
Andy Shevchenko