[PATCH v2] hte: tegra194: don't access struct gpio_chip

From: Bartosz Golaszewski
Date: Fri Oct 13 2023 - 03:23:51 EST


From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>

Using struct gpio_chip is not safe as it will disappear if the
underlying driver is unbound for any reason. Switch to using reference
counted struct gpio_device and its dedicated accessors.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
Tested-by: Dipen Patel <dipenp@xxxxxxxxxx>
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
[andy: used gpio_device_find_by_fwnode()]
Reviewed-by: Dipen Patel <dipenp@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20231010151709.4104747-3-andriy.shevchenko@xxxxxxxxxxxxxxx
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
Dipen,

Can you retest this patch now rebased on top of current GPIO for-next?

v1 -> v2:
- rebase on top of current gpio/for-next

drivers/hte/hte-tegra194.c | 30 ++++++++++++++++--------------
1 file changed, 16 insertions(+), 14 deletions(-)

diff --git a/drivers/hte/hte-tegra194.c b/drivers/hte/hte-tegra194.c
index 6fe6897047ac..341a134cb7d0 100644
--- a/drivers/hte/hte-tegra194.c
+++ b/drivers/hte/hte-tegra194.c
@@ -132,7 +132,7 @@ struct tegra_hte_soc {
const struct tegra_hte_data *prov_data;
struct tegra_hte_line_data *line_data;
struct hte_chip *chip;
- struct gpio_chip *c;
+ struct gpio_device *gdev;
void __iomem *regs;
};

@@ -418,7 +418,7 @@ static int tegra_hte_line_xlate(struct hte_chip *gc,
* HTE/GTE namespace.
*/
if (gs->prov_data->type == HTE_TEGRA_TYPE_GPIO && !args) {
- line_id = desc->attr.line_id - gs->c->base;
+ line_id = desc->attr.line_id - gpio_device_get_base(gs->gdev);
map = gs->prov_data->map;
map_sz = gs->prov_data->map_sz;
} else if (gs->prov_data->type == HTE_TEGRA_TYPE_GPIO && args) {
@@ -645,7 +645,7 @@ static bool tegra_hte_match_from_linedata(const struct hte_chip *chip,
if (!hte_dev || (hte_dev->prov_data->type != HTE_TEGRA_TYPE_GPIO))
return false;

- return hte_dev->c == gpiod_to_chip(hdesc->attr.line_data);
+ return hte_dev->gdev == gpiod_to_gpio_device(hdesc->attr.line_data);
}

static const struct of_device_id tegra_hte_of_match[] = {
@@ -673,14 +673,11 @@ static void tegra_gte_disable(void *data)
tegra_hte_writel(gs, HTE_TECTRL, 0);
}

-static int tegra_get_gpiochip_from_name(struct gpio_chip *chip, void *data)
+static void tegra_hte_put_gpio_device(void *data)
{
- return !strcmp(chip->label, data);
-}
+ struct gpio_device *gdev = data;

-static int tegra_gpiochip_match(struct gpio_chip *chip, void *data)
-{
- return chip->fwnode == of_node_to_fwnode(data);
+ gpio_device_put(gdev);
}

static int tegra_hte_probe(struct platform_device *pdev)
@@ -760,8 +757,8 @@ static int tegra_hte_probe(struct platform_device *pdev)

if (of_device_is_compatible(dev->of_node,
"nvidia,tegra194-gte-aon")) {
- hte_dev->c = gpiochip_find("tegra194-gpio-aon",
- tegra_get_gpiochip_from_name);
+ hte_dev->gdev =
+ gpio_device_find_by_label("tegra194-gpio-aon");
} else {
gpio_ctrl = of_parse_phandle(dev->of_node,
"nvidia,gpio-controller",
@@ -772,14 +769,19 @@ static int tegra_hte_probe(struct platform_device *pdev)
return -ENODEV;
}

- hte_dev->c = gpiochip_find(gpio_ctrl,
- tegra_gpiochip_match);
+ hte_dev->gdev =
+ gpio_device_find_by_fwnode(of_fwnode_handle(gpio_ctrl));
of_node_put(gpio_ctrl);
}

- if (!hte_dev->c)
+ if (!hte_dev->gdev)
return dev_err_probe(dev, -EPROBE_DEFER,
"wait for gpio controller\n");
+
+ ret = devm_add_action_or_reset(dev, tegra_hte_put_gpio_device,
+ hte_dev->gdev);
+ if (ret)
+ return ret;
}

hte_dev->chip = gc;
--
2.39.2