leds: leds-lp55xx: Support ENGINE program up to 128 bytes

Some LED chip supports up to 16 pages and with some magic they can be
divided in 4 page for each ENGINE + 1 for each MUX. Following this we
can support bigger programs up to 128 bytes.

Rework the update_program_memory function to support program of multiple
pages instead of hardcoding it to one page per programs.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Link: https://lore.kernel.org/r/20240626160027.19703-19-ansuelsmth@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>

Author: Ansuel

drivers/leds/leds-lp5523.c

@@ -21,7 +21,6 @@
 
 #include "leds-lp55xx-common.h"
 
-#define LP5523_PROGRAM_LENGTH		32	/* bytes */
 /* Memory is used like this:
  * 0x00 engine 1 program
  * 0x10 engine 2 program
@@ -172,7 +171,7 @@ static int lp5523_init_program_engine(struct lp55xx_chip *chip)
 	int ret;
 	u8 status;
 	/* one pattern per engine setting LED MUX start and stop addresses */
-	static const u8 pattern[][LP5523_PROGRAM_LENGTH] =  {
+	static const u8 pattern[][LP55xx_BYTES_PER_PAGE] =  {
 		{ 0x9c, 0x30, 0x9c, 0xb0, 0x9d, 0x80, 0xd8, 0x00, 0},
 		{ 0x9c, 0x40, 0x9c, 0xc0, 0x9d, 0x80, 0xd8, 0x00, 0},
 		{ 0x9c, 0x50, 0x9c, 0xd0, 0x9d, 0x80, 0xd8, 0x00, 0},
@@ -196,7 +195,7 @@ static int lp5523_init_program_engine(struct lp55xx_chip *chip)
 		chip->engine_idx = i;
 		lp55xx_load_engine(chip);
 
-		for (j = 0; j < LP5523_PROGRAM_LENGTH; j++) {
+		for (j = 0; j < LP55xx_BYTES_PER_PAGE; j++) {
 			ret = lp55xx_write(chip, LP5523_REG_PROG_MEM + j,
 					pattern[i - 1][j]);
 			if (ret)

drivers/leds/leds-lp5562.c

@@ -19,7 +19,6 @@
 
 #include "leds-lp55xx-common.h"
 
-#define LP5562_PROGRAM_LENGTH		32
 #define LP5562_MAX_LEDS			4
 
 /* ENABLE Register 00h */
@@ -212,9 +211,9 @@ static void lp5562_write_program_memory(struct lp55xx_chip *chip,
 /* check the size of program count */
 static inline bool _is_pc_overflow(struct lp55xx_predef_pattern *ptn)
 {
-	return ptn->size_r >= LP5562_PROGRAM_LENGTH ||
-	       ptn->size_g >= LP5562_PROGRAM_LENGTH ||
-	       ptn->size_b >= LP5562_PROGRAM_LENGTH;
+	return ptn->size_r >= LP55xx_BYTES_PER_PAGE ||
+	       ptn->size_g >= LP55xx_BYTES_PER_PAGE ||
+	       ptn->size_b >= LP55xx_BYTES_PER_PAGE;
 }
 
 static int lp5562_run_predef_led_pattern(struct lp55xx_chip *chip, int mode)

drivers/leds/leds-lp55xx-common.c

@@ -27,7 +27,8 @@
 /* OP MODE require at least 153 us to clear regs */
 #define LP55XX_CMD_SLEEP		200
 
-#define LP55xx_PROGRAM_LENGTH		32
+#define LP55xx_PROGRAM_PAGES		16
+#define LP55xx_MAX_PROGRAM_LENGTH	(LP55xx_BYTES_PER_PAGE * 4) /* 128 bytes (4 pages) */
 
 /*
  * Program Memory Operations
@@ -172,12 +173,16 @@ int lp55xx_update_program_memory(struct lp55xx_chip *chip,
 {
 	enum lp55xx_engine_index idx = chip->engine_idx;
 	const struct lp55xx_device_config *cfg = chip->cfg;
-	u8 pattern[LP55xx_PROGRAM_LENGTH] = { };
+	u8 pattern[LP55xx_MAX_PROGRAM_LENGTH] = { };
 	u8 start_addr = cfg->prog_mem_base.addr;
-	int i = 0, offset = 0;
-	int ret;
+	int page, i = 0, offset = 0;
+	int program_length, ret;
+
+	program_length = LP55xx_BYTES_PER_PAGE;
+	if (cfg->pages_per_engine)
+		program_length *= cfg->pages_per_engine;
 
-	while ((offset < size - 1) && (i < LP55xx_PROGRAM_LENGTH)) {
+	while ((offset < size - 1) && (i < program_length)) {
 		unsigned int cmd;
 		int nrchars;
 		char c[3];
@@ -206,12 +211,20 @@ 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_PROGRAM_LENGTH * idx;
+		start_addr += LP55xx_BYTES_PER_PAGE * idx;
 
-	for (i = 0; i < LP55xx_PROGRAM_LENGTH; i++) {
-		ret = lp55xx_write(chip, start_addr + i, pattern[i]);
-		if (ret)
-			return -EINVAL;
+	for (page = 0; page < program_length / LP55xx_BYTES_PER_PAGE; page++) {
+		/* Write to the next page each 32 bytes (if supported) */
+		if (cfg->pages_per_engine)
+			lp55xx_write(chip, LP55xx_REG_PROG_PAGE_SEL,
+				     LP55xx_PAGE_OFFSET(idx, cfg->pages_per_engine) + page);
+
+		for (i = 0; i < LP55xx_BYTES_PER_PAGE; i++) {
+			ret = lp55xx_write(chip, start_addr + i,
+					   pattern[i + (page * LP55xx_BYTES_PER_PAGE)]);
+			if (ret)
+				return -EINVAL;
+		}
 	}
 
 	return size;
@@ -224,13 +237,19 @@ EXPORT_SYMBOL_GPL(lp55xx_update_program_memory);
 
 void lp55xx_firmware_loaded_cb(struct lp55xx_chip *chip)
 {
+	const struct lp55xx_device_config *cfg = chip->cfg;
 	const struct firmware *fw = chip->fw;
+	int program_length;
+
+	program_length = LP55xx_BYTES_PER_PAGE;
+	if (cfg->pages_per_engine)
+		program_length *= cfg->pages_per_engine;
 
 	/*
 	 * the firmware is encoded in ascii hex character, with 2 chars
 	 * per byte
 	 */
-	if (fw->size > LP55xx_PROGRAM_LENGTH * 2) {
+	if (fw->size > program_length * 2) {
 		dev_err(&chip->cl->dev, "firmware data size overflow: %zu\n",
 			fw->size);
 		return;
@@ -1276,7 +1295,7 @@ static struct lp55xx_platform_data *lp55xx_of_populate_pdata(struct device *dev,
 int lp55xx_probe(struct i2c_client *client)
 {
 	const struct i2c_device_id *id = i2c_client_get_device_id(client);
-	int ret;
+	int program_length, ret;
 	struct lp55xx_chip *chip;
 	struct lp55xx_led *led;
 	struct lp55xx_platform_data *pdata = dev_get_platdata(&client->dev);
@@ -1300,6 +1319,17 @@ int lp55xx_probe(struct i2c_client *client)
 		}
 	}
 
+	/* Validate max program page */
+	program_length = LP55xx_BYTES_PER_PAGE;
+	if (chip->cfg->pages_per_engine)
+		program_length *= chip->cfg->pages_per_engine;
+
+	/* support a max of 128bytes */
+	if (program_length > LP55xx_MAX_PROGRAM_LENGTH) {
+		dev_err(&client->dev, "invalid pages_per_engine configured\n");
+		return -EINVAL;
+	}
+
 	led = devm_kcalloc(&client->dev,
 			   pdata->num_channels, sizeof(*led), GFP_KERNEL);
 	if (!led)

drivers/leds/leds-lp55xx-common.h

@@ -14,6 +14,8 @@
 
 #include <linux/led-class-multicolor.h>
 
+#define LP55xx_BYTES_PER_PAGE		32      /* bytes */
+
 enum lp55xx_engine_index {
 	LP55XX_ENGINE_INVALID,
 	LP55XX_ENGINE_1,