diff mbox series

[v2] i2c: pxa: move to generic GPIO recovery

Message ID 20201004091656.1004575-1-codrin.ciubotariu@microchip.com (mailing list archive)
State New, archived
Headers show
Series [v2] i2c: pxa: move to generic GPIO recovery | expand

Commit Message

Codrin Ciubotariu Oct. 4, 2020, 9:16 a.m. UTC
Starting with
commit 75820314de26 ("i2c: core: add generic I2C GPIO recovery")
GPIO bus recovery is supported by the I2C core, so we can remove the
driver implementation and use that one instead.

Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
---

This patch is not tested.

Changes in v2:
 - readded the pinctrl state change to default from the
   unprepare_recovery callback;

 drivers/i2c/busses/i2c-pxa.c | 73 +++---------------------------------
 1 file changed, 6 insertions(+), 67 deletions(-)

Comments

Russell King (Oracle) Oct. 4, 2020, 9:24 a.m. UTC | #1
On Sun, Oct 04, 2020 at 12:16:56PM +0300, Codrin Ciubotariu wrote:
> Starting with
> commit 75820314de26 ("i2c: core: add generic I2C GPIO recovery")
> GPIO bus recovery is supported by the I2C core, so we can remove the
> driver implementation and use that one instead.
> 
> Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
> ---
> 
> This patch is not tested.
> 
> Changes in v2:
>  - readded the pinctrl state change to default from the
>    unprepare_recovery callback;

I don't think you've build tested this patch...

> diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
> index 35ca2c02c9b9..006cc1d5931f 100644
> --- a/drivers/i2c/busses/i2c-pxa.c
> +++ b/drivers/i2c/busses/i2c-pxa.c
> @@ -264,9 +264,6 @@ struct pxa_i2c {
>  	u32			hs_mask;
>  
>  	struct i2c_bus_recovery_info recovery;
> -	struct pinctrl		*pinctrl;
> -	struct pinctrl_state	*pinctrl_default;
> -	struct pinctrl_state	*pinctrl_recovery;

i2c_pxa_unprepare_recovery() refers to pinctrl and pinctrl_default which
you've retained in this version of the patch, but you've deleted the
members from this structure - which will lead to a build error.
Codrin Ciubotariu Oct. 4, 2020, 9:52 a.m. UTC | #2
On 04.10.2020 12:24, Russell King - ARM Linux admin wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> 
> On Sun, Oct 04, 2020 at 12:16:56PM +0300, Codrin Ciubotariu wrote:
>> Starting with
>> commit 75820314de26 ("i2c: core: add generic I2C GPIO recovery")
>> GPIO bus recovery is supported by the I2C core, so we can remove the
>> driver implementation and use that one instead.
>>
>> Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
>> ---
>>
>> This patch is not tested.
>>
>> Changes in v2:
>>   - readded the pinctrl state change to default from the
>>     unprepare_recovery callback;
> 
> I don't think you've build tested this patch...

You're right, sorry about that. I used a wrong config... Will fix it 
right away.

Best regards,
Codrin

> 
>> diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
>> index 35ca2c02c9b9..006cc1d5931f 100644
>> --- a/drivers/i2c/busses/i2c-pxa.c
>> +++ b/drivers/i2c/busses/i2c-pxa.c
>> @@ -264,9 +264,6 @@ struct pxa_i2c {
>>        u32                     hs_mask;
>>
>>        struct i2c_bus_recovery_info recovery;
>> -     struct pinctrl          *pinctrl;
>> -     struct pinctrl_state    *pinctrl_default;
>> -     struct pinctrl_state    *pinctrl_recovery;
> 
> i2c_pxa_unprepare_recovery() refers to pinctrl and pinctrl_default which
> you've retained in this version of the patch, but you've deleted the
> members from this structure - which will lead to a build error.
> 
> --
> RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
> FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!
>
diff mbox series

Patch

diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
index 35ca2c02c9b9..006cc1d5931f 100644
--- a/drivers/i2c/busses/i2c-pxa.c
+++ b/drivers/i2c/busses/i2c-pxa.c
@@ -264,9 +264,6 @@  struct pxa_i2c {
 	u32			hs_mask;
 
 	struct i2c_bus_recovery_info recovery;
-	struct pinctrl		*pinctrl;
-	struct pinctrl_state	*pinctrl_default;
-	struct pinctrl_state	*pinctrl_recovery;
 };
 
 #define _IBMR(i2c)	((i2c)->reg_ibmr)
@@ -1305,8 +1302,6 @@  static void i2c_pxa_prepare_recovery(struct i2c_adapter *adap)
 	 */
 	gpiod_set_value(i2c->recovery.scl_gpiod, ibmr & IBMR_SCLS);
 	gpiod_set_value(i2c->recovery.sda_gpiod, ibmr & IBMR_SDAS);
-
-	WARN_ON(pinctrl_select_state(i2c->pinctrl, i2c->pinctrl_recovery));
 }
 
 static void i2c_pxa_unprepare_recovery(struct i2c_adapter *adap)
@@ -1347,76 +1342,20 @@  static int i2c_pxa_init_recovery(struct pxa_i2c *i2c)
 	if (IS_ENABLED(CONFIG_I2C_PXA_SLAVE))
 		return 0;
 
-	i2c->pinctrl = devm_pinctrl_get(dev);
-	if (PTR_ERR(i2c->pinctrl) == -ENODEV)
-		i2c->pinctrl = NULL;
-	if (IS_ERR(i2c->pinctrl))
-		return PTR_ERR(i2c->pinctrl);
-
-	if (!i2c->pinctrl)
-		return 0;
-
-	i2c->pinctrl_default = pinctrl_lookup_state(i2c->pinctrl,
-						    PINCTRL_STATE_DEFAULT);
-	i2c->pinctrl_recovery = pinctrl_lookup_state(i2c->pinctrl, "recovery");
-
-	if (IS_ERR(i2c->pinctrl_default) || IS_ERR(i2c->pinctrl_recovery)) {
-		dev_info(dev, "missing pinmux recovery information: %ld %ld\n",
-			 PTR_ERR(i2c->pinctrl_default),
-			 PTR_ERR(i2c->pinctrl_recovery));
-		return 0;
-	}
-
-	/*
-	 * Claiming GPIOs can influence the pinmux state, and may glitch the
-	 * I2C bus. Do this carefully.
-	 */
-	bri->scl_gpiod = devm_gpiod_get(dev, "scl", GPIOD_OUT_HIGH_OPEN_DRAIN);
-	if (bri->scl_gpiod == ERR_PTR(-EPROBE_DEFER))
-		return -EPROBE_DEFER;
-	if (IS_ERR(bri->scl_gpiod)) {
-		dev_info(dev, "missing scl gpio recovery information: %pe\n",
-			 bri->scl_gpiod);
-		return 0;
-	}
-
-	/*
-	 * We have SCL. Pull SCL low and wait a bit so that SDA glitches
-	 * have no effect.
-	 */
-	gpiod_direction_output(bri->scl_gpiod, 0);
-	udelay(10);
-	bri->sda_gpiod = devm_gpiod_get(dev, "sda", GPIOD_OUT_HIGH_OPEN_DRAIN);
-
-	/* Wait a bit in case of a SDA glitch, and then release SCL. */
-	udelay(10);
-	gpiod_direction_output(bri->scl_gpiod, 1);
-
-	if (bri->sda_gpiod == ERR_PTR(-EPROBE_DEFER))
-		return -EPROBE_DEFER;
-
-	if (IS_ERR(bri->sda_gpiod)) {
-		dev_info(dev, "missing sda gpio recovery information: %pe\n",
-			 bri->sda_gpiod);
+	bri->pinctrl = devm_pinctrl_get(dev);
+	if (PTR_ERR(bri->pinctrl) == -ENODEV) {
+		bri->pinctrl = NULL;
 		return 0;
 	}
+	if (IS_ERR(bri->pinctrl))
+		return PTR_ERR(bri->pinctrl);
 
 	bri->prepare_recovery = i2c_pxa_prepare_recovery;
 	bri->unprepare_recovery = i2c_pxa_unprepare_recovery;
-	bri->recover_bus = i2c_generic_scl_recovery;
 
 	i2c->adap.bus_recovery_info = bri;
 
-	/*
-	 * Claiming GPIOs can change the pinmux state, which confuses the
-	 * pinctrl since pinctrl's idea of the current setting is unaffected
-	 * by the pinmux change caused by claiming the GPIO. Work around that
-	 * by switching pinctrl to the GPIO state here. We do it this way to
-	 * avoid glitching the I2C bus.
-	 */
-	pinctrl_select_state(i2c->pinctrl, i2c->pinctrl_recovery);
-
-	return pinctrl_select_state(i2c->pinctrl, i2c->pinctrl_default);
+	return 0;
 }
 
 static int i2c_pxa_probe(struct platform_device *dev)