On Tue, Jan 7, 2014 at 12:42 PM, Pavel Machek <pavel@xxxxxx> wrote:
> Hi!
>
> There's some locking weirdness, and few missing comments in lp5523
> driver.
>
> Now, this is untested patch from my reverse-engineering. I hope I
> understood things right...
>
> In particular, there's unbalanced unlock in
> lp5523_update_program_memory, and lp5523_update_program_memory needs
> to be protected by the lock.
>
> Comments? Does someone maintain this?
>
I think Milo Kim is maintaining this driver for the LP55xx chip family.
Thanks,
-Bryan
> Thanks,
> Pavel
> Signed-off-by: Pavel Machek <pavel@xxxxxx>
>
>
> diff --git a/drivers/leds/leds-lp5523.c b/drivers/leds/leds-lp5523.c
> index c00f55e4..e8b83e9 100644
> --- a/drivers/leds/leds-lp5523.c
> +++ b/drivers/leds/leds-lp5523.c
> @@ -34,7 +34,15 @@
>
> #include "leds-lp55xx-common.h"
>
> -#define LP5523_PROGRAM_LENGTH 32
> +#define LP5523_PROGRAM_LENGTH 32 /* bytes */
> +/* Memory is used like this:
> + 0x00 engine 1 program
> + 0x10 engine 2 program
> + 0x20 engine 3 program
> + 0x30 engine 1 muxing info
> + 0x40 engine 2 muxing info
> + 0x50 engine 3 muxing info
> + ...and offsets are hard-coded all around :-( */
> #define LP5523_MAX_LEDS 9
>
> /* Registers */
> @@ -265,20 +273,25 @@ static int lp5523_init_program_engine(struct lp55xx_chip *chip)
> /* one pattern per engine setting LED MUX start and stop addresses */
> static const u8 pattern[][LP5523_PROGRAM_LENGTH] = {
> { 0x9c, 0x30, 0x9c, 0xb0, 0x9d, 0x80, 0xd8, 0x00, 0},
> + /* 9c30 -- mux_map_start(0x30)
> + 9cb0 -- mux_ld_end(0x50)
> + 9d80 -- mux_sel???(0x00)
> + d800 -- invalid?? */
> { 0x9c, 0x40, 0x9c, 0xc0, 0x9d, 0x80, 0xd8, 0x00, 0},
> { 0x9c, 0x50, 0x9c, 0xd0, 0x9d, 0x80, 0xd8, 0x00, 0},
> };
>
> - /* hardcode 32 bytes of memory for each engine from program memory */
> + /* hardcode LP5523_PROGRAM_LENGTH bytes of memory for each
> + engine from program memory */
> ret = lp55xx_write(chip, LP5523_REG_CH1_PROG_START, 0x00);
> if (ret)
> return ret;
>
> - ret = lp55xx_write(chip, LP5523_REG_CH2_PROG_START, 0x10);
> + ret = lp55xx_write(chip, LP5523_REG_CH2_PROG_START, LP5523_PROGRAM_LENGTH / 2);
> if (ret)
> return ret;
>
> - ret = lp55xx_write(chip, LP5523_REG_CH3_PROG_START, 0x20);
> + ret = lp55xx_write(chip, LP5523_REG_CH3_PROG_START, LP5523_PROGRAM_LENGTH);
> if (ret)
> return ret;
>
> @@ -346,10 +359,8 @@ static int lp5523_update_program_memory(struct lp55xx_chip *chip,
>
> for (i = 0; i < LP5523_PROGRAM_LENGTH; i++) {
> ret = lp55xx_write(chip, LP5523_REG_PROG_MEM + i, pattern[i]);
> - if (ret) {
> - mutex_unlock(&chip->lock);
> + if (ret)
> return -EINVAL;
> - }
> }
>
> return size;
> @@ -551,15 +562,17 @@ static ssize_t store_engine_load(struct device *dev,
> {
> struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
> struct lp55xx_chip *chip = led->chip;
> + ssize_t res;
>
> mutex_lock(&chip->lock);
>
> chip->engine_idx = nr;
> lp5523_load_engine_and_select_page(chip);
>
> + res = lp5523_update_program_memory(chip, buf, len);
> mutex_unlock(&chip->lock);
>
> - return lp5523_update_program_memory(chip, buf, len);
> + return res;
> }
> store_load(1)
> store_load(2)
> diff --git a/drivers/leds/leds-lp8501.c b/drivers/leds/leds-lp8501.c
> index 8d55a780..ae5c6fe 100644
> --- a/drivers/leds/leds-lp8501.c
> +++ b/drivers/leds/leds-lp8501.c
> @@ -262,7 +262,7 @@ static void lp8501_firmware_loaded(struct lp55xx_chip *chip)
> }
>
> /*
> - * Program momery sequence
> + * Program memory sequence
> * 1) set engine mode to "LOAD"
> * 2) write firmware data into program memory
> */
>
> --
> (english) http://www.livejournal.com/~pavelmachek
> (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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