[PATCH 03/10] leds: lp5521: restore legacy device attributes

From: Milo Kim
Date: Thu Aug 08 2013 - 04:03:36 EST


git commit 9ce7cb170f97f83a78dc948bf7d25690f15e1328
may cause an application confict, engineN_mode and engineN_load.
This interface should be maintained for compatibility.

Restored device attributes are 'engineN_mode' and 'engineN_load'.
A 'selftest' attribute macro is replaced with LP55xx common macro.

Use a mutex in lp5521_update_program_memory()
: This function is called when an user-application writes a 'engineN_load' file
or pattern data is loaded from generic firmware interface.
So, writing program memory should be protected.
If an error occurs on accessing this area, just it returns as -EINVAL quickly.
This error code is exact same as old driver function, lp5521_do_store_load()
because it should be kept for an user-application compatibility.
Even the driver is changed, we can use the application without re-compiling
sources.

'led_pattern' attribute is not included
: engineN_mode and _load were created for custom user-application.
'led_pattern' is an exception. I added this attribute not for custom application
but for simple test. Now it is used only in LP5562 driver, not LP5521.

Signed-off-by: Milo Kim <milo.kim@xxxxxx>
---
drivers/leds/leds-lp5521.c | 104 ++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 100 insertions(+), 4 deletions(-)

diff --git a/drivers/leds/leds-lp5521.c b/drivers/leds/leds-lp5521.c
index 9e28dd0..c00f922 100644
--- a/drivers/leds/leds-lp5521.c
+++ b/drivers/leds/leds-lp5521.c
@@ -251,10 +251,20 @@ static int lp5521_update_program_memory(struct lp55xx_chip *chip,
goto err;

program_size = i;
- for (i = 0; i < program_size; i++)
- lp55xx_write(chip, addr[idx] + i, pattern[i]);

- return 0;
+ mutex_lock(&chip->lock);
+
+ for (i = 0; i < program_size; i++) {
+ ret = lp55xx_write(chip, addr[idx] + i, pattern[i]);
+ if (ret) {
+ mutex_unlock(&chip->lock);
+ return -EINVAL;
+ }
+ }
+
+ mutex_unlock(&chip->lock);
+
+ return size;

err:
dev_err(&chip->cl->dev, "wrong pattern format\n");
@@ -365,6 +375,80 @@ static void lp5521_led_brightness_work(struct work_struct *work)
mutex_unlock(&chip->lock);
}

+static ssize_t show_engine_mode(struct device *dev,
+ struct device_attribute *attr,
+ char *buf, int nr)
+{
+ struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
+ struct lp55xx_chip *chip = led->chip;
+ enum lp55xx_engine_mode mode = chip->engines[nr - 1].mode;
+
+ switch (mode) {
+ case LP55XX_ENGINE_RUN:
+ return sprintf(buf, "run\n");
+ case LP55XX_ENGINE_LOAD:
+ return sprintf(buf, "load\n");
+ case LP55XX_ENGINE_DISABLED:
+ default:
+ return sprintf(buf, "disabled\n");
+ }
+}
+show_mode(1)
+show_mode(2)
+show_mode(3)
+
+static ssize_t store_engine_mode(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len, int nr)
+{
+ struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
+ struct lp55xx_chip *chip = led->chip;
+ struct lp55xx_engine *engine = &chip->engines[nr - 1];
+
+ mutex_lock(&chip->lock);
+
+ chip->engine_idx = nr;
+
+ if (!strncmp(buf, "run", 3)) {
+ lp5521_run_engine(chip, true);
+ engine->mode = LP55XX_ENGINE_RUN;
+ } else if (!strncmp(buf, "load", 4)) {
+ lp5521_stop_engine(chip);
+ lp5521_load_engine(chip);
+ engine->mode = LP55XX_ENGINE_LOAD;
+ } else if (!strncmp(buf, "disabled", 8)) {
+ lp5521_stop_engine(chip);
+ engine->mode = LP55XX_ENGINE_DISABLED;
+ }
+
+ mutex_unlock(&chip->lock);
+
+ return len;
+}
+store_mode(1)
+store_mode(2)
+store_mode(3)
+
+static ssize_t store_engine_load(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len, int nr)
+{
+ struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
+ struct lp55xx_chip *chip = led->chip;
+
+ mutex_lock(&chip->lock);
+
+ chip->engine_idx = nr;
+ lp5521_load_engine(chip);
+
+ mutex_unlock(&chip->lock);
+
+ return lp5521_update_program_memory(chip, buf, len);
+}
+store_load(1)
+store_load(2)
+store_load(3)
+
static ssize_t lp5521_selftest(struct device *dev,
struct device_attribute *attr,
char *buf)
@@ -381,9 +465,21 @@ static ssize_t lp5521_selftest(struct device *dev,
}

/* device attributes */
-static DEVICE_ATTR(selftest, S_IRUGO, lp5521_selftest, NULL);
+static LP55XX_DEV_ATTR_RW(engine1_mode, show_engine1_mode, store_engine1_mode);
+static LP55XX_DEV_ATTR_RW(engine2_mode, show_engine2_mode, store_engine2_mode);
+static LP55XX_DEV_ATTR_RW(engine3_mode, show_engine3_mode, store_engine3_mode);
+static LP55XX_DEV_ATTR_WO(engine1_load, store_engine1_load);
+static LP55XX_DEV_ATTR_WO(engine2_load, store_engine2_load);
+static LP55XX_DEV_ATTR_WO(engine3_load, store_engine3_load);
+static LP55XX_DEV_ATTR_RO(selftest, lp5521_selftest);

static struct attribute *lp5521_attributes[] = {
+ &dev_attr_engine1_mode.attr,
+ &dev_attr_engine2_mode.attr,
+ &dev_attr_engine3_mode.attr,
+ &dev_attr_engine1_load.attr,
+ &dev_attr_engine2_load.attr,
+ &dev_attr_engine3_load.attr,
&dev_attr_selftest.attr,
NULL
};
--
1.7.9.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/