leds: lp5523: restore legacy device attributes

git commit db6eaf8388a413a5ee1b4547ce78506b9c6456b0
(leds-lp5523: use generic firmware interface) causes an application conflict.
This interface should be maintained for compatibility.

Restored device attributes are 'engineN_mode', 'engineN_load' and
'engineN_leds'. (N = 1, 2 or 3)
A 'selftest' attribute macro is replaced with LP55xx common macro.
Those are accessed when a LED pattern is run by an application.

Use a mutex in lp5523_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, lp5523_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.

Reported-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Milo Kim <milo.kim@ti.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>

1 files changed, 223 insertions, 4 deletions

diff --git a/drivers/leds/leds-lp5523.c b/drivers/leds/leds-lp5523.c
index 29c8b19a445e..9b8be6f6c595 100644
--- a/drivers/leds/leds-lp5523.c
+++ b/drivers/leds/leds-lp5523.c
@@ -74,6 +74,9 @@
 #define LP5523_PAGE_ENG1                0
 #define LP5523_PAGE_ENG2                1
 #define LP5523_PAGE_ENG3                2
+#define LP5523_PAGE_MUX1                3
+#define LP5523_PAGE_MUX2                4
+#define LP5523_PAGE_MUX3                5
 
 /* Program Memory Operations */
 #define LP5523_MODE_ENG1_M              0x30    /* Operation Mode Register */
@@ -98,6 +101,8 @@
 #define LP5523_RUN_ENG2                 0x08
 #define LP5523_RUN_ENG3                 0x02
 
+#define LED_ACTIVE(mux, led)            (!!(mux & (0x0001 << led)))
+
 enum lp5523_chip_id {
         LP5523,
         LP55231,
@@ -338,10 +343,20 @@ static int lp5523_update_program_memory(struct lp55xx_chip *chip,
                 goto err;
 
         update_size = i;
-        for (i = 0; i < update_size; i++)
-                lp55xx_write(chip, LP5523_REG_PROG_MEM + i, pattern[i]);
 
-        return 0;
+        mutex_lock(&chip->lock);
+
+        for (i = 0; i < update_size; i++) {
+                ret = lp55xx_write(chip, LP5523_REG_PROG_MEM + 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");
@@ -368,6 +383,192 @@ static void lp5523_firmware_loaded(struct lp55xx_chip *chip)
         lp5523_update_program_memory(chip, fw->data, fw->size);
 }
 
+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)) {
+                lp5523_run_engine(chip, true);
+                engine->mode = LP55XX_ENGINE_RUN;
+        } else if (!strncmp(buf, "load", 4)) {
+                lp5523_stop_engine(chip);
+                lp5523_load_engine(chip);
+                engine->mode = LP55XX_ENGINE_LOAD;
+        } else if (!strncmp(buf, "disabled", 8)) {
+                lp5523_stop_engine(chip);
+                engine->mode = LP55XX_ENGINE_DISABLED;
+        }
+
+        mutex_unlock(&chip->lock);
+
+        return len;
+}
+store_mode(1)
+store_mode(2)
+store_mode(3)
+
+static int lp5523_mux_parse(const char *buf, u16 *mux, size_t len)
+{
+        u16 tmp_mux = 0;
+        int i;
+
+        len = min_t(int, len, LP5523_MAX_LEDS);
+
+        for (i = 0; i < len; i++) {
+                switch (buf[i]) {
+                case '1':
+                        tmp_mux |= (1 << i);
+                        break;
+                case '0':
+                        break;
+                case '\n':
+                        i = len;
+                        break;
+                default:
+                        return -1;
+                }
+        }
+        *mux = tmp_mux;
+
+        return 0;
+}
+
+static void lp5523_mux_to_array(u16 led_mux, char *array)
+{
+        int i, pos = 0;
+        for (i = 0; i < LP5523_MAX_LEDS; i++)
+                pos += sprintf(array + pos, "%x", LED_ACTIVE(led_mux, i));
+
+        array[pos] = '\0';
+}
+
+static ssize_t show_engine_leds(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;
+        char mux[LP5523_MAX_LEDS + 1];
+
+        lp5523_mux_to_array(chip->engines[nr - 1].led_mux, mux);
+
+        return sprintf(buf, "%s\n", mux);
+}
+show_leds(1)
+show_leds(2)
+show_leds(3)
+
+static int lp5523_load_mux(struct lp55xx_chip *chip, u16 mux, int nr)
+{
+        struct lp55xx_engine *engine = &chip->engines[nr - 1];
+        int ret;
+        u8 mux_page[] = {
+                [LP55XX_ENGINE_1] = LP5523_PAGE_MUX1,
+                [LP55XX_ENGINE_2] = LP5523_PAGE_MUX2,
+                [LP55XX_ENGINE_3] = LP5523_PAGE_MUX3,
+        };
+
+        lp5523_load_engine(chip);
+
+        ret = lp55xx_write(chip, LP5523_REG_PROG_PAGE_SEL, mux_page[nr]);
+        if (ret)
+                return ret;
+
+        ret = lp55xx_write(chip, LP5523_REG_PROG_MEM , (u8)(mux >> 8));
+        if (ret)
+                return ret;
+
+        ret = lp55xx_write(chip, LP5523_REG_PROG_MEM + 1, (u8)(mux));
+        if (ret)
+                return ret;
+
+        engine->led_mux = mux;
+        return 0;
+}
+
+static ssize_t store_engine_leds(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];
+        u16 mux = 0;
+        ssize_t ret;
+
+        if (lp5523_mux_parse(buf, &mux, len))
+                return -EINVAL;
+
+        mutex_lock(&chip->lock);
+
+        chip->engine_idx = nr;
+        ret = -EINVAL;
+
+        if (engine->mode != LP55XX_ENGINE_LOAD)
+                goto leave;
+
+        if (lp5523_load_mux(chip, mux, nr))
+                goto leave;
+
+        ret = len;
+leave:
+        mutex_unlock(&chip->lock);
+        return ret;
+}
+store_leds(1)
+store_leds(2)
+store_leds(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;
+        lp5523_load_engine_and_select_page(chip);
+
+        mutex_unlock(&chip->lock);
+
+        return lp5523_update_program_memory(chip, buf, len);
+}
+store_load(1)
+store_load(2)
+store_load(3)
+
 static ssize_t lp5523_selftest(struct device *dev,
                                struct device_attribute *attr,
                                char *buf)
@@ -467,9 +668,27 @@ static void lp5523_led_brightness_work(struct work_struct *work)
         mutex_unlock(&chip->lock);
 }
 
-static DEVICE_ATTR(selftest, S_IRUGO, lp5523_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_RW(engine1_leds, show_engine1_leds, store_engine1_leds);
+static LP55XX_DEV_ATTR_RW(engine2_leds, show_engine2_leds, store_engine2_leds);
+static LP55XX_DEV_ATTR_RW(engine3_leds, show_engine3_leds, store_engine3_leds);
+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, lp5523_selftest);
 
 static struct attribute *lp5523_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_engine1_leds.attr,
+        &dev_attr_engine2_leds.attr,
+        &dev_attr_engine3_leds.attr,
         &dev_attr_selftest.attr,
         NULL,
 };