Gregor Herburger <gregor.herburger@xxxxxxxxxxxxxxx> writes:
> Currently the i2c-imx driver assumes that for bus recovery the i2c pins
> can be reconfigured as gpio via pinctrl.
>
> But bus recovery can also be done with a gpio electrically connected to
> i2c scl.
>
> Modify i2c_imx_init_recovery_info to allow bus recovery on platforms
> without pinctrl. In this case only use scl-gpio and
> i2c_generic_scl_recovery.
Why not move to use the generic GPIO recovery instead? Will something
like this be able to cover at least the same scenarios as your change?
>From 7e432496bae8c7ac35c21504bc1cd03f1dfef97f Mon Sep 17 00:00:00 2001
Message-ID: <7e432496bae8c7ac35c21504bc1cd03f1dfef97f.1702971634.git.esben@xxxxxxxxxx>
From: Esben Haabendal <esben@xxxxxxxxxx>
Date: Tue, 25 May 2021 11:25:44 +0200
Subject: [PATCH] i2c: imx: move to generic GPIO recovery
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.
As a nice side-effect, pinctrl becomes optional, allowing bus recovery on
LS1021A, which does not have such luxury, but can be wired up to use extra
fixed GPIO pins.
Signed-off-by: Esben Haabendal <esben@xxxxxxxxxx>
---
drivers/i2c/busses/i2c-imx.c | 62 ++++--------------------------------
1 file changed, 7 insertions(+), 55 deletions(-)
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index 1775a79aeba2..824d8bbb9be5 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -212,10 +212,6 @@ struct imx_i2c_struct {
const struct imx_i2c_hwdata *hwdata;
struct i2c_bus_recovery_info rinfo;
- struct pinctrl *pinctrl;
- struct pinctrl_state *pinctrl_pins_default;
- struct pinctrl_state *pinctrl_pins_gpio;
-
struct imx_i2c_dma *dma;
struct i2c_client *slave;
enum i2c_slave_event last_slave_event;
@@ -1357,24 +1353,6 @@ static int i2c_imx_xfer_atomic(struct i2c_adapter *adapter,
return result;
}
-static void i2c_imx_prepare_recovery(struct i2c_adapter *adap)
-{
- struct imx_i2c_struct *i2c_imx;
-
- i2c_imx = container_of(adap, struct imx_i2c_struct, adapter);
-
- pinctrl_select_state(i2c_imx->pinctrl, i2c_imx->pinctrl_pins_gpio);
-}
-
-static void i2c_imx_unprepare_recovery(struct i2c_adapter *adap)
-{
- struct imx_i2c_struct *i2c_imx;
-
- i2c_imx = container_of(adap, struct imx_i2c_struct, adapter);
-
- pinctrl_select_state(i2c_imx->pinctrl, i2c_imx->pinctrl_pins_default);
-}
-
/*
* We switch SCL and SDA to their GPIO function and do some bitbanging
* for bus recovery. These alternative pinmux settings can be
@@ -1385,43 +1363,17 @@ static void i2c_imx_unprepare_recovery(struct i2c_adapter *adap)
static int i2c_imx_init_recovery_info(struct imx_i2c_struct *i2c_imx,
struct platform_device *pdev)
{
- struct i2c_bus_recovery_info *rinfo = &i2c_imx->rinfo;
+ struct i2c_bus_recovery_info *bri = &i2c_imx->rinfo;
- i2c_imx->pinctrl = devm_pinctrl_get(&pdev->dev);
- if (!i2c_imx->pinctrl) {
- dev_info(&pdev->dev, "pinctrl unavailable, bus recovery not supported\n");
+ bri->pinctrl = devm_pinctrl_get(&pdev->dev);
+ if (PTR_ERR(bri->pinctrl) == -ENODEV) {
+ bri->pinctrl = NULL;
return 0;
}
- if (IS_ERR(i2c_imx->pinctrl)) {
- dev_info(&pdev->dev, "can't get pinctrl, bus recovery not supported\n");
- return PTR_ERR(i2c_imx->pinctrl);
- }
-
- i2c_imx->pinctrl_pins_default = pinctrl_lookup_state(i2c_imx->pinctrl,
- PINCTRL_STATE_DEFAULT);
- i2c_imx->pinctrl_pins_gpio = pinctrl_lookup_state(i2c_imx->pinctrl,
- "gpio");
- rinfo->sda_gpiod = devm_gpiod_get(&pdev->dev, "sda", GPIOD_IN);
- rinfo->scl_gpiod = devm_gpiod_get(&pdev->dev, "scl", GPIOD_OUT_HIGH_OPEN_DRAIN);
-
- if (PTR_ERR(rinfo->sda_gpiod) == -EPROBE_DEFER ||
- PTR_ERR(rinfo->scl_gpiod) == -EPROBE_DEFER) {
- return -EPROBE_DEFER;
- } else if (IS_ERR(rinfo->sda_gpiod) ||
- IS_ERR(rinfo->scl_gpiod) ||
- IS_ERR(i2c_imx->pinctrl_pins_default) ||
- IS_ERR(i2c_imx->pinctrl_pins_gpio)) {
- dev_dbg(&pdev->dev, "recovery information incomplete\n");
- return 0;
- }
-
- dev_dbg(&pdev->dev, "using scl%s for recovery\n",
- rinfo->sda_gpiod ? ",sda" : "");
+ if (IS_ERR(bri->pinctrl))
+ return PTR_ERR(bri->pinctrl);
- rinfo->prepare_recovery = i2c_imx_prepare_recovery;
- rinfo->unprepare_recovery = i2c_imx_unprepare_recovery;
- rinfo->recover_bus = i2c_generic_scl_recovery;
- i2c_imx->adapter.bus_recovery_info = rinfo;
+ i2c_imx->adapter.bus_recovery_info = bri;
return 0;
}
--
2.43.0
/Esben
