Hi,
On Mon, May 29, 2023 at 03:43:01PM +0800, carlos.song@xxxxxxx wrote:
> From: Clark Wang <xiaoning.wang@xxxxxxx>
>
> Add bus recovery feature for LPI2C.
> Need add gpio pinctrl, scl-gpios and sda-gpios configuration in dts.
please update the commit message according to the dts changes, as
well.
[...]
> +static void lpi2c_imx_prepare_recovery(struct i2c_adapter *adap)
> +{
> + struct lpi2c_imx_struct *lpi2c_imx;
> +
> + lpi2c_imx = container_of(adap, struct lpi2c_imx_struct, adapter);
> +
> + pinctrl_select_state(lpi2c_imx->pinctrl, lpi2c_imx->pinctrl_pins_gpio);
> +}
> +
> +static void lpi2c_imx_unprepare_recovery(struct i2c_adapter *adap)
> +{
> + struct lpi2c_imx_struct *lpi2c_imx;
> +
> + lpi2c_imx = container_of(adap, struct lpi2c_imx_struct, adapter);
> +
> + pinctrl_select_state(lpi2c_imx->pinctrl, lpi2c_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
> + * described in the device tree by a separate pinctrl state "gpio". If
is this still true?
> + * this is missing this is not a big problem, the only implication is
> + * that we can't do bus recovery.
> + */
> +static int lpi2c_imx_init_recovery_info(struct lpi2c_imx_struct *lpi2c_imx,
> + struct platform_device *pdev)
> +{
> + struct i2c_bus_recovery_info *rinfo = &lpi2c_imx->rinfo;
> +
> + lpi2c_imx->pinctrl = devm_pinctrl_get(&pdev->dev);
> + if (!lpi2c_imx->pinctrl || IS_ERR(lpi2c_imx->pinctrl)) {
> + dev_info(&pdev->dev, "can't get pinctrl, bus recovery not supported\n");
> + return PTR_ERR(lpi2c_imx->pinctrl);
> + }
> +
> + lpi2c_imx->pinctrl_pins_default = pinctrl_lookup_state(lpi2c_imx->pinctrl,
> + PINCTRL_STATE_DEFAULT);
> + lpi2c_imx->pinctrl_pins_gpio = pinctrl_lookup_state(lpi2c_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(lpi2c_imx->pinctrl_pins_default) ||
> + IS_ERR(lpi2c_imx->pinctrl_pins_gpio)) {
> + dev_dbg(&pdev->dev, "recovery information incomplete\n");
> + return 0;
> + }
Why not use these assignement from the default
i2c_init_recovery()? Is there anything you are doing I am not
seeing?
> +
> + dev_info(&pdev->dev, "using scl%s for recovery\n",
> + rinfo->sda_gpiod ? ",sda" : "");
is there any case when sda_gpiod is NULL?
> +
> + rinfo->prepare_recovery = lpi2c_imx_prepare_recovery;
> + rinfo->unprepare_recovery = lpi2c_imx_unprepare_recovery;
> + rinfo->recover_bus = i2c_generic_scl_recovery;
> + lpi2c_imx->adapter.bus_recovery_info = rinfo;
do you need also the set_scl() function? It should be mandatory.
> +
> + return 0;
> +}
Besides, this is a copy/paste from i2c-imx.c, any chance to put
the two things together?
Andi
