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Date: Fri, 9 Sep 2016 13:40:04 +0200
From: Linus Walleij <linus.walleij@...aro.org>
To: Sebastian Reichel <sre@...nel.org>,
Dmitry Eremin-Solenikov <dbaryshkov@...il.com>,
linux-kernel@...r.kernel.org
Cc: David Woodhouse <dwmw2@...radead.org>,
Linus Walleij <linus.walleij@...aro.org>,
Heiko Stuebner <heiko@...ech.de>,
Lars-Peter Clausen <lars@...afoo.de>
Subject: [PATCH] power: gpio_charger: switch to using GPIO descriptors
The GPIO charger is using a mix of the legacy GPIO interface
and <linux/of_gpio.h> which is not the modern way to use GPIOs.
Refactor like this:
- Use a GPIO descriptor for the GPIO line used to monitor the
charger.
- Fetch the descriptor with devm_gpiod_get() as the first
method.
- If this fails and we are *not* using device tree, then
start looking to see if we can use platform data instead.
- After looking up and requesting a GPIO number with the
legacy API, convert it to a descriptor.
This way we can later isolate and drop the legacy code as
more platforms move over to using descriptors.
Cc: Dmitry Eremin-Solenikov <dbaryshkov@...il.com>
Cc: Heiko Stuebner <heiko@...ech.de>
Cc: Lars-Peter Clausen <lars@...afoo.de>
Signed-off-by: Linus Walleij <linus.walleij@...aro.org>
---
I would be very happy if some people can test this. I think
only the chromebook use it from device tree, but I'm equally
interested in the legacy usecase to work as nice as before.
---
drivers/power/gpio-charger.c | 84 ++++++++++++++++++++++++++------------------
1 file changed, 50 insertions(+), 34 deletions(-)
diff --git a/drivers/power/gpio-charger.c b/drivers/power/gpio-charger.c
index c5869b1941ac..001731e88718 100644
--- a/drivers/power/gpio-charger.c
+++ b/drivers/power/gpio-charger.c
@@ -14,7 +14,7 @@
*/
#include <linux/device.h>
-#include <linux/gpio.h>
+#include <linux/gpio.h> /* For legacy platform data */
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
@@ -23,7 +23,7 @@
#include <linux/power_supply.h>
#include <linux/slab.h>
#include <linux/of.h>
-#include <linux/of_gpio.h>
+#include <linux/gpio/consumer.h>
#include <linux/power/gpio-charger.h>
@@ -34,6 +34,8 @@ struct gpio_charger {
struct power_supply *charger;
struct power_supply_desc charger_desc;
+ struct gpio_desc *gpiod;
+ bool legacy_gpio_requested;
};
static irqreturn_t gpio_charger_irq(int irq, void *devid)
@@ -58,7 +60,8 @@ static int gpio_charger_get_property(struct power_supply *psy,
switch (psp) {
case POWER_SUPPLY_PROP_ONLINE:
- val->intval = !!gpio_get_value_cansleep(pdata->gpio);
+ val->intval = gpiod_get_value_cansleep(gpio_charger->gpiod);
+ /* This xor is only ever used with legacy pdata GPIO */
val->intval ^= pdata->gpio_active_low;
break;
default:
@@ -78,7 +81,6 @@ struct gpio_charger_platform_data *gpio_charger_parse_dt(struct device *dev)
struct device_node *np = dev->of_node;
struct gpio_charger_platform_data *pdata;
const char *chargetype;
- enum of_gpio_flags flags;
int ret;
if (!np)
@@ -89,16 +91,6 @@ struct gpio_charger_platform_data *gpio_charger_parse_dt(struct device *dev)
return ERR_PTR(-ENOMEM);
pdata->name = np->name;
-
- pdata->gpio = of_get_gpio_flags(np, 0, &flags);
- if (pdata->gpio < 0) {
- if (pdata->gpio != -EPROBE_DEFER)
- dev_err(dev, "could not get charger gpio\n");
- return ERR_PTR(pdata->gpio);
- }
-
- pdata->gpio_active_low = !!(flags & OF_GPIO_ACTIVE_LOW);
-
pdata->type = POWER_SUPPLY_TYPE_UNKNOWN;
ret = of_property_read_string(np, "charger-type", &chargetype);
if (ret >= 0) {
@@ -144,11 +136,6 @@ static int gpio_charger_probe(struct platform_device *pdev)
}
}
- if (!gpio_is_valid(pdata->gpio)) {
- dev_err(&pdev->dev, "Invalid gpio pin\n");
- return -EINVAL;
- }
-
gpio_charger = devm_kzalloc(&pdev->dev, sizeof(*gpio_charger),
GFP_KERNEL);
if (!gpio_charger) {
@@ -156,6 +143,45 @@ static int gpio_charger_probe(struct platform_device *pdev)
return -ENOMEM;
}
+ /*
+ * This will fetch a GPIO descriptor from device tree, ACPI or
+ * boardfile descriptor tables. It's good to try this first.
+ */
+ gpio_charger->gpiod = devm_gpiod_get(&pdev->dev, NULL, GPIOD_IN);
+
+ /*
+ * If this fails and we're not using device tree, try the
+ * legacy platform data method.
+ */
+ if (IS_ERR(gpio_charger->gpiod) && !pdev->dev.of_node) {
+ /* Non-DT: use legacy GPIO numbers */
+ if (!gpio_is_valid(pdata->gpio)) {
+ dev_err(&pdev->dev, "Invalid gpio pin in pdata\n");
+ return -EINVAL;
+ }
+ ret = gpio_request(pdata->gpio, dev_name(&pdev->dev));
+ if (ret) {
+ dev_err(&pdev->dev, "Failed to request gpio pin: %d\n",
+ ret);
+ return ret;
+ }
+ gpio_charger->legacy_gpio_requested = true;
+ ret = gpio_direction_input(pdata->gpio);
+ if (ret) {
+ dev_err(&pdev->dev, "Failed to set gpio to input: %d\n",
+ ret);
+ goto err_gpio_free;
+ }
+ /* Then convert this to gpiod for now */
+ gpio_charger->gpiod = gpio_to_desc(pdata->gpio);
+ } else if (IS_ERR(gpio_charger->gpiod)) {
+ /* Just try again if this happens */
+ if (PTR_ERR(gpio_charger->gpiod) == -EPROBE_DEFER)
+ return -EPROBE_DEFER;
+ dev_err(&pdev->dev, "error getting GPIO descriptor\n");
+ return PTR_ERR(gpio_charger->gpiod);
+ }
+
charger_desc = &gpio_charger->charger_desc;
charger_desc->name = pdata->name ? pdata->name : "gpio-charger";
@@ -169,17 +195,6 @@ static int gpio_charger_probe(struct platform_device *pdev)
psy_cfg.of_node = pdev->dev.of_node;
psy_cfg.drv_data = gpio_charger;
- ret = gpio_request(pdata->gpio, dev_name(&pdev->dev));
- if (ret) {
- dev_err(&pdev->dev, "Failed to request gpio pin: %d\n", ret);
- goto err_free;
- }
- ret = gpio_direction_input(pdata->gpio);
- if (ret) {
- dev_err(&pdev->dev, "Failed to set gpio to input: %d\n", ret);
- goto err_gpio_free;
- }
-
gpio_charger->pdata = pdata;
gpio_charger->charger = power_supply_register(&pdev->dev,
@@ -191,7 +206,7 @@ static int gpio_charger_probe(struct platform_device *pdev)
goto err_gpio_free;
}
- irq = gpio_to_irq(pdata->gpio);
+ irq = gpiod_to_irq(gpio_charger->gpiod);
if (irq > 0) {
ret = request_any_context_irq(irq, gpio_charger_irq,
IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
@@ -209,8 +224,8 @@ static int gpio_charger_probe(struct platform_device *pdev)
return 0;
err_gpio_free:
- gpio_free(pdata->gpio);
-err_free:
+ if (gpio_charger->legacy_gpio_requested)
+ gpio_free(pdata->gpio);
return ret;
}
@@ -223,7 +238,8 @@ static int gpio_charger_remove(struct platform_device *pdev)
power_supply_unregister(gpio_charger->charger);
- gpio_free(gpio_charger->pdata->gpio);
+ if (gpio_charger->legacy_gpio_requested)
+ gpio_free(gpio_charger->pdata->gpio);
return 0;
}
--
2.7.4
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