[PATCH v3] i2c: pxa: move to generic GPIO recovery

From: Codrin Ciubotariu
Date: Sun Oct 04 2020 - 06:08:13 EST


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@xxxxxxxxxxxxx>
---

patch not tested.

Changes in v3:
- fix compile errors from unprepare_recovery callback

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

drivers/i2c/busses/i2c-pxa.c | 76 ++++--------------------------------
1 file changed, 8 insertions(+), 68 deletions(-)

diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
index 35ca2c02c9b9..a636ea0eb50a 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)
@@ -1305,13 +1302,12 @@ 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)
{
struct pxa_i2c *i2c = adap->algo_data;
+ struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
u32 isr;

/*
@@ -1325,7 +1321,7 @@ static void i2c_pxa_unprepare_recovery(struct i2c_adapter *adap)
i2c_pxa_do_reset(i2c);
}

- WARN_ON(pinctrl_select_state(i2c->pinctrl, i2c->pinctrl_default));
+ WARN_ON(pinctrl_select_state(bri->pinctrl, bri->pins_default));

dev_dbg(&i2c->adap.dev, "recovery: IBMR 0x%08x ISR 0x%08x\n",
readl(_IBMR(i2c)), readl(_ISR(i2c)));
@@ -1347,76 +1343,20 @@ 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)
--
2.25.1