From: Andrei Lalaev Date: Wed, 20 Aug 2025 08:47:12 +0000 (+0200) Subject: leds: leds-lp55xx: Use correct address for memory programming X-Git-Tag: v6.18-rc1~161^2~5 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=d6058316d16ee0d1861c0550051b2492efb54b79;p=thirdparty%2Flinux.git leds: leds-lp55xx: Use correct address for memory programming Memory programming doesn't work for devices without page support. For example, LP5562 has 3 engines but doesn't support pages, the start address is changed depending on engine number. According to datasheet [1], the PROG MEM register addresses for each engine are as follows: Engine 1: 0x10 Engine 2: 0x30 Engine 3: 0x50 However, the current implementation incorrectly calculates the address of PROG MEM register using the engine index starting from 1: prog_mem_base = 0x10 LP55xx_BYTES_PER_PAGE = 0x20 Engine 1: 0x10 + 0x20 * 1 = 0x30 Engine 2: 0x10 + 0x20 * 2 = 0x50 Engine 3: 0x10 + 0x20 * 3 = 0x70 This results in writing to the wrong engine memory, causing pattern programming to fail. To correct it, the engine index should be decreased: Engine 1: 0x10 + 0x20 * 0 = 0x10 Engine 2: 0x10 + 0x20 * 1 = 0x30 Engine 3: 0x10 + 0x20 * 2 = 0x50 1 - https://www.ti.com/lit/ds/symlink/lp5562.pdf Fixes: 31379a57cf2f ("leds: leds-lp55xx: Generalize update_program_memory function") Signed-off-by: Andrei Lalaev Link: https://lore.kernel.org/r/20250820-lp5562-prog-mem-address-v1-1-8569647fa71d@anton-paar.com Signed-off-by: Lee Jones --- diff --git a/drivers/leds/leds-lp55xx-common.c b/drivers/leds/leds-lp55xx-common.c index e71456a56ab8d..fd447eb7eb15e 100644 --- a/drivers/leds/leds-lp55xx-common.c +++ b/drivers/leds/leds-lp55xx-common.c @@ -212,7 +212,7 @@ int lp55xx_update_program_memory(struct lp55xx_chip *chip, * For LED chip that support page, PAGE is already set in load_engine. */ if (!cfg->pages_per_engine) - start_addr += LP55xx_BYTES_PER_PAGE * idx; + start_addr += LP55xx_BYTES_PER_PAGE * (idx - 1); for (page = 0; page < program_length / LP55xx_BYTES_PER_PAGE; page++) { /* Write to the next page each 32 bytes (if supported) */