Re: [PATCH 2/2] leds: leds-pca995x: Add support for NXP PCA9956B

From: Marek Vasut
Date: Wed Jul 10 2024 - 08:21:47 EST


On 7/10/24 8:15 AM, Pieterjan Camerlynck via B4 Relay wrote:
From: Pieterjan Camerlynck <pieterjanca@xxxxxxxxx>

Add support for PCA9956B chip, which belongs to the same family.

This chip features 24 instead of 16 outputs, so add a chipdef struct to
deal with the different register layouts.

Signed-off-by: Pieterjan Camerlynck <pieterjanca@xxxxxxxxx>
---
drivers/leds/leds-pca995x.c | 88 ++++++++++++++++++++++++++-------------------
1 file changed, 52 insertions(+), 36 deletions(-)

diff --git a/drivers/leds/leds-pca995x.c b/drivers/leds/leds-pca995x.c
index 78215dff1499..4cd2828a3f2d 100644
--- a/drivers/leds/leds-pca995x.c
+++ b/drivers/leds/leds-pca995x.c
@@ -19,10 +19,6 @@
#define PCA995X_MODE1 0x00
#define PCA995X_MODE2 0x01
#define PCA995X_LEDOUT0 0x02
-#define PCA9955B_PWM0 0x08
-#define PCA9952_PWM0 0x0A
-#define PCA9952_IREFALL 0x43
-#define PCA9955B_IREFALL 0x45
/* Auto-increment disabled. Normal mode */
#define PCA995X_MODE1_CFG 0x00
@@ -34,17 +30,43 @@
#define PCA995X_LDRX_MASK 0x3
#define PCA995X_LDRX_BITS 2
-#define PCA995X_MAX_OUTPUTS 16
#define PCA995X_OUTPUTS_PER_REG 4
#define PCA995X_IREFALL_FULL_CFG 0xFF
#define PCA995X_IREFALL_HALF_CFG (PCA995X_IREFALL_FULL_CFG / 2)
-#define PCA995X_TYPE_NON_B 0
-#define PCA995X_TYPE_B 1
-
#define ldev_to_led(c) container_of(c, struct pca995x_led, ldev)
+enum pca995x_type {
+ pca9952,
+ pca9955b,
+ pca9956b,
+};

This enum shouldn't be needed (see below).

+struct pca995x_chipdef {
+ unsigned int num_leds;
+ u8 pwm_base;
+ u8 irefall;
+};
+
+static const struct pca995x_chipdef pca995x_chipdefs[] = {

Define three separate static const struct pca995x_chipdef {} , one for each chip type ...

+ [pca9952] = {
+ .num_leds = 16,
+ .pwm_base = 0x0a,
+ .irefall = 0x43,
+ },
+ [pca9955b] = {
+ .num_leds = 16,
+ .pwm_base = 0x08,
+ .irefall = 0x45,
+ },
+ [pca9956b] = {
+ .num_leds = 24,
+ .pwm_base = 0x0a,
+ .irefall = 0x40,
+ },
+};
+
struct pca995x_led {
unsigned int led_no;
struct led_classdev ldev;
@@ -52,9 +74,9 @@ struct pca995x_led {
};
struct pca995x_chip {
+ const struct pca995x_chipdef *chipdef;
struct regmap *regmap;
- struct pca995x_led leds[PCA995X_MAX_OUTPUTS];
- int btype;
+ struct pca995x_led leds[];
};
static int pca995x_brightness_set(struct led_classdev *led_cdev,
@@ -62,10 +84,11 @@ static int pca995x_brightness_set(struct led_classdev *led_cdev,
{
struct pca995x_led *led = ldev_to_led(led_cdev);
struct pca995x_chip *chip = led->chip;
+ const struct pca995x_chipdef *chipdef = chip->chipdef;
u8 ledout_addr, pwmout_addr;
int shift, ret;
- pwmout_addr = (chip->btype ? PCA9955B_PWM0 : PCA9952_PWM0) + led->led_no;
+ pwmout_addr = (chipdef->pwm_base) + led->led_no;
ledout_addr = PCA995X_LEDOUT0 + (led->led_no / PCA995X_OUTPUTS_PER_REG);
shift = PCA995X_LDRX_BITS * (led->led_no % PCA995X_OUTPUTS_PER_REG);
@@ -101,24 +124,24 @@ static const struct regmap_config pca995x_regmap = {
static int pca995x_probe(struct i2c_client *client)
{
- struct fwnode_handle *led_fwnodes[PCA995X_MAX_OUTPUTS] = { 0 };
struct fwnode_handle *np, *child;
struct device *dev = &client->dev;
+ const struct pca995x_chipdef *chipdef;
struct pca995x_chip *chip;
struct pca995x_led *led;
- int i, btype, reg, ret;
+ int reg, ret;
- btype = (unsigned long)device_get_match_data(&client->dev);
+ chipdef = device_get_match_data(&client->dev);
np = dev_fwnode(dev);
if (!np)
return -ENODEV;
- chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
+ chip = devm_kzalloc(dev, struct_size(chip, leds, chipdef->num_leds), GFP_KERNEL);
if (!chip)
return -ENOMEM;
- chip->btype = btype;
+ chip->chipdef = chipdef;
chip->regmap = devm_regmap_init_i2c(client, &pca995x_regmap);
if (IS_ERR(chip->regmap))
return PTR_ERR(chip->regmap);
@@ -126,41 +149,34 @@ static int pca995x_probe(struct i2c_client *client)
i2c_set_clientdata(client, chip);
fwnode_for_each_available_child_node(np, child) {
+ struct led_init_data init_data = {};
+
ret = fwnode_property_read_u32(child, "reg", &reg);
if (ret) {
fwnode_handle_put(child);
return ret;
}
- if (reg < 0 || reg >= PCA995X_MAX_OUTPUTS || led_fwnodes[reg]) {
+ if (reg < 0 || reg >= chipdef->num_leds) {
fwnode_handle_put(child);
return -EINVAL;
}
led = &chip->leds[reg];
- led_fwnodes[reg] = child;
led->chip = chip;
led->led_no = reg;
led->ldev.brightness_set_blocking = pca995x_brightness_set;
led->ldev.max_brightness = 255;
- }
-
- for (i = 0; i < PCA995X_MAX_OUTPUTS; i++) {
- struct led_init_data init_data = {};
-
- if (!led_fwnodes[i])
- continue;
-
- init_data.fwnode = led_fwnodes[i];
+ init_data.fwnode = child;
ret = devm_led_classdev_register_ext(dev,
- &chip->leds[i].ldev,
+ &led->ldev,
&init_data);
if (ret < 0) {
fwnode_handle_put(child);
return dev_err_probe(dev, ret,
"Could not register LED %s\n",
- chip->leds[i].ldev.name);
+ led->ldev.name);
}
}
@@ -170,21 +186,21 @@ static int pca995x_probe(struct i2c_client *client)
return ret;
/* IREF Output current value for all LEDn outputs */
- return regmap_write(chip->regmap,
- btype ? PCA9955B_IREFALL : PCA9952_IREFALL,
- PCA995X_IREFALL_HALF_CFG);
+ return regmap_write(chip->regmap, chipdef->irefall, PCA995X_IREFALL_HALF_CFG);
}
static const struct i2c_device_id pca995x_id[] = {
- { "pca9952", .driver_data = (kernel_ulong_t)PCA995X_TYPE_NON_B },
- { "pca9955b", .driver_data = (kernel_ulong_t)PCA995X_TYPE_B },
+ { "pca9952", .driver_data = (kernel_ulong_t)&pca995x_chipdefs[pca9952] },
+ { "pca9955b", .driver_data = (kernel_ulong_t)&pca995x_chipdefs[pca9955b] },
+ { "pca9956b", .driver_data = (kernel_ulong_t)&pca995x_chipdefs[pca9956b] },

... pass pointer to each (separate) chip type structure here ...

{}
};
MODULE_DEVICE_TABLE(i2c, pca995x_id);
static const struct of_device_id pca995x_of_match[] = {
- { .compatible = "nxp,pca9952", .data = (void *)PCA995X_TYPE_NON_B },
- { .compatible = "nxp,pca9955b", .data = (void *)PCA995X_TYPE_B },
+ { .compatible = "nxp,pca9952", .data = &pca995x_chipdefs[pca9952] },
+ { .compatible = "nxp,pca9955b", . data = &pca995x_chipdefs[pca9955b] },
+ { .compatible = "nxp,pca9956b", .data = &pca995x_chipdefs[pca9956b] },

... and here.

In pca995x_probe() , cache pointer to the whole struct pca995x_chipdef and use its members all over the driver. That's how you can get rid of the enum .