Input: ads7846 - switch to devm initialization

This simplies the code a lot and fixes some potential resource leaks in
the error return paths.

Signed-off-by: Daniel Mack <daniel@zonque.org>
Link: https://lore.kernel.org/r/20210907200726.2034962-4-daniel@zonque.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index b9c8496..eaa8714 100644 (file)
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -101,10 +101,6 @@ struct ads7846 {
        struct spi_device       *spi;
        struct regulator        *reg;
 
-#if IS_ENABLED(CONFIG_HWMON)
-       struct device           *hwmon;
-#endif
-
        u16                     model;
        u16                     vref_mv;
        u16                     vref_delay_usecs;
@@ -554,6 +550,8 @@ __ATTRIBUTE_GROUPS(ads7846_attr);
 
 static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts)
 {
+       struct device *hwmon;
+
        /* hwmon sensors need a reference voltage */
        switch (ts->model) {
        case 7846:
@@ -574,17 +572,11 @@ static int ads784x_hwmon_register(struct spi_device *spi, struct ads7846 *ts)
                break;
        }
 
-       ts->hwmon = hwmon_device_register_with_groups(&spi->dev, spi->modalias,
-                                                     ts, ads7846_attr_groups);
+       hwmon = devm_hwmon_device_register_with_groups(&spi->dev,
+                                                      spi->modalias, ts,
+                                                      ads7846_attr_groups);
 
-       return PTR_ERR_OR_ZERO(ts->hwmon);
-}
-
-static void ads784x_hwmon_unregister(struct spi_device *spi,
-                                    struct ads7846 *ts)
-{
-       if (ts->hwmon)
-               hwmon_device_unregister(ts->hwmon);
+       return PTR_ERR_OR_ZERO(hwmon);
 }
 
 #else
@@ -593,11 +585,6 @@ static inline int ads784x_hwmon_register(struct spi_device *spi,
 {
        return 0;
 }
-
-static inline void ads784x_hwmon_unregister(struct spi_device *spi,
-                                           struct ads7846 *ts)
-{
-}
 #endif
 
 static ssize_t ads7846_pen_down_show(struct device *dev,
@@ -1019,8 +1006,8 @@ static int ads7846_setup_pendown(struct spi_device *spi,
                ts->get_pendown_state = pdata->get_pendown_state;
        } else if (gpio_is_valid(pdata->gpio_pendown)) {
 
-               err = gpio_request_one(pdata->gpio_pendown, GPIOF_IN,
-                                      "ads7846_pendown");
+               err = devm_gpio_request_one(&spi->dev, pdata->gpio_pendown,
+                                           GPIOF_IN, "ads7846_pendown");
                if (err) {
                        dev_err(&spi->dev,
                                "failed to request/setup pendown GPIO%d: %d\n",
@@ -1217,6 +1204,11 @@ static const struct ads7846_platform_data *ads7846_probe_dt(struct device *dev)
 }
 #endif
 
+static void ads7846_regulator_disable(void *regulator)
+{
+       regulator_disable(regulator);
+}
+
 static int ads7846_probe(struct spi_device *spi)
 {
        const struct ads7846_platform_data *pdata;
@@ -1251,13 +1243,17 @@ static int ads7846_probe(struct spi_device *spi)
        if (err < 0)
                return err;
 
-       ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL);
-       packet = kzalloc(sizeof(struct ads7846_packet), GFP_KERNEL);
-       input_dev = input_allocate_device();
-       if (!ts || !packet || !input_dev) {
-               err = -ENOMEM;
-               goto err_free_mem;
-       }
+       ts = devm_kzalloc(dev, sizeof(struct ads7846), GFP_KERNEL);
+       if (!ts)
+               return -ENOMEM;
+
+       packet = devm_kzalloc(dev, sizeof(struct ads7846_packet), GFP_KERNEL);
+       if (!packet)
+               return -ENOMEM;
+
+       input_dev = devm_input_allocate_device(dev);
+       if (!input_dev)
+               return -ENOMEM;
 
        spi_set_drvdata(spi, ts);
 
@@ -1271,10 +1267,8 @@ static int ads7846_probe(struct spi_device *spi)
        pdata = dev_get_platdata(dev);
        if (!pdata) {
                pdata = ads7846_probe_dt(dev);
-               if (IS_ERR(pdata)) {
-                       err = PTR_ERR(pdata);
-                       goto err_free_mem;
-               }
+               if (IS_ERR(pdata))
+                       return PTR_ERR(pdata);
        }
 
        ts->model = pdata->model ? : 7846;
@@ -1296,7 +1290,7 @@ static int ads7846_probe(struct spi_device *spi)
 
        err = ads7846_setup_pendown(spi, ts, pdata);
        if (err)
-               goto err_free_mem;
+               return err;
 
        if (pdata->penirq_recheck_delay_usecs)
                ts->penirq_recheck_delay_usecs =
@@ -1309,7 +1303,6 @@ static int ads7846_probe(struct spi_device *spi)
 
        input_dev->name = ts->name;
        input_dev->phys = ts->phys;
-       input_dev->dev.parent = dev;
 
        input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
        input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
@@ -1343,41 +1336,47 @@ static int ads7846_probe(struct spi_device *spi)
 
        ads7846_setup_spi_msg(ts, pdata);
 
-       ts->reg = regulator_get(dev, "vcc");
+       ts->reg = devm_regulator_get(dev, "vcc");
        if (IS_ERR(ts->reg)) {
                err = PTR_ERR(ts->reg);
                dev_err(dev, "unable to get regulator: %d\n", err);
-               goto err_free_gpio;
+               return err;
        }
 
        err = regulator_enable(ts->reg);
        if (err) {
                dev_err(dev, "unable to enable regulator: %d\n", err);
-               goto err_put_regulator;
+               return err;
        }
 
+       err = devm_add_action_or_reset(dev, ads7846_regulator_disable, ts->reg);
+       if (err)
+               return err;
+
        irq_flags = pdata->irq_flags ? : IRQF_TRIGGER_FALLING;
        irq_flags |= IRQF_ONESHOT;
 
-       err = request_threaded_irq(spi->irq, ads7846_hard_irq, ads7846_irq,
-                                  irq_flags, dev->driver->name, ts);
+       err = devm_request_threaded_irq(dev, spi->irq,
+                                       ads7846_hard_irq, ads7846_irq,
+                                       irq_flags, dev->driver->name, ts);
        if (err && !pdata->irq_flags) {
                dev_info(dev,
                        "trying pin change workaround on irq %d\n", spi->irq);
                irq_flags |= IRQF_TRIGGER_RISING;
-               err = request_threaded_irq(spi->irq,
-                                 ads7846_hard_irq, ads7846_irq,
-                                 irq_flags, dev->driver->name, ts);
+               err = devm_request_threaded_irq(dev, spi->irq,
+                                               ads7846_hard_irq, ads7846_irq,
+                                               irq_flags, dev->driver->name,
+                                               ts);
        }
 
        if (err) {
                dev_dbg(dev, "irq %d busy?\n", spi->irq);
-               goto err_disable_regulator;
+               return err;
        }
 
        err = ads784x_hwmon_register(spi, ts);
        if (err)
-               goto err_free_irq;
+               return err;
 
        dev_info(dev, "touchscreen, irq %d\n", spi->irq);
 
@@ -1390,13 +1389,13 @@ static int ads7846_probe(struct spi_device *spi)
        else
                (void) ads7846_read12_ser(dev, READ_12BIT_SER(vaux));
 
-       err = sysfs_create_group(&dev->kobj, &ads784x_attr_group);
+       err = devm_device_add_group(dev, &ads784x_attr_group);
        if (err)
-               goto err_remove_hwmon;
+               return err;
 
        err = input_register_device(input_dev);
        if (err)
-               goto err_remove_attr_group;
+               return err;
 
        device_init_wakeup(dev, pdata->wakeup);
 
@@ -1408,54 +1407,13 @@ static int ads7846_probe(struct spi_device *spi)
                devm_kfree(dev, (void *)pdata);
 
        return 0;
-
- err_remove_attr_group:
-       sysfs_remove_group(&dev->kobj, &ads784x_attr_group);
- err_remove_hwmon:
-       ads784x_hwmon_unregister(spi, ts);
- err_free_irq:
-       free_irq(spi->irq, ts);
- err_disable_regulator:
-       regulator_disable(ts->reg);
- err_put_regulator:
-       regulator_put(ts->reg);
- err_free_gpio:
-       if (!ts->get_pendown_state)
-               gpio_free(ts->gpio_pendown);
- err_free_mem:
-       input_free_device(input_dev);
-       kfree(packet);
-       kfree(ts);
-       return err;
 }
 
 static int ads7846_remove(struct spi_device *spi)
 {
        struct ads7846 *ts = spi_get_drvdata(spi);
 
-       sysfs_remove_group(&spi->dev.kobj, &ads784x_attr_group);
-
-       ads7846_disable(ts);
-       free_irq(ts->spi->irq, ts);
-
-       input_unregister_device(ts->input);
-
-       ads784x_hwmon_unregister(spi, ts);
-
-       regulator_put(ts->reg);
-
-       if (!ts->get_pendown_state) {
-               /*
-                * If we are not using specialized pendown method we must
-                * have been relying on gpio we set up ourselves.
-                */
-               gpio_free(ts->gpio_pendown);
-       }
-
-       kfree(ts->packet);
-       kfree(ts);
-
-       dev_dbg(&spi->dev, "unregistered touchscreen\n");
+       ads7846_stop(ts);
 
        return 0;
 }