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Date: Mon, 24 Jun 2024 16:31:44 +0200
From: Vicentiu Galanopulo <vicentiu.galanopulo@...ote-tech.co.uk>
To: pavel@....cz, lee@...nel.org, linux-kernel@...r.kernel.org,
linux-leds@...r.kernel.org
Cc: pavel@....cz, linux-kernel@...r.kernel.org, linux-leds@...r.kernel.org
Subject: Re: [PATCH v2 2/2] leds: Add LED1202 I2C driver
On Thu, Jun 20, 2024 at 06:55:43PM +0100, Lee Jones wrote:
> I'm going do a very quick once through of this one.
>
> There is a lot of work to do.
>
> > The LED1202 is a 12-channel low quiescent
>
> Please line wrap at 70-something chars not 40
>
Ok, will do. I'm using Visual Code as editor.
Do you know any config options for it?
If not maybe another editor that is free
and works on Mac ARM.
> > current LED driver. The output current can
> > be adjusted separately for each channel by
> > 8-bit analog (current sink input) and
> > 12-bit digital (PWM) dimming control.
> >
> > The LED1202 implements 12 low-side current
> > generators with independent dimming control.
> > Internal volatile memory allows the user
> > to store up to 8 different patterns, each
> > pattern is a particular output configuration
> > in terms of PWM duty-cycle (on 4096 steps).
> > Analog dimming (on 256 steps) is
> > per channel but common to all patterns.
> >
> > Each active=1 device tree LED node will
> > have a corresponding entry in /sys/class/leds
> > with the label name.
> > The brightness property corresponds to the
> > per channel analog dimming, while the
> > patterns[1-8] to the PWM dimming control.
> >
> > Signed-off-by: Vicentiu Galanopulo <vicentiu.galanopulo@...ote-tech.co.uk>
> > ---
> >
> > Changes in v2:
> > - Fix build error for device_attribute modes
> >
> > drivers/leds/Kconfig | 10 +
> > drivers/leds/Makefile | 1 +
> > drivers/leds/leds-led1202.c | 617 ++++++++++++++++++++++++++++++++++++
> > 3 files changed, 628 insertions(+)
> > create mode 100644 drivers/leds/leds-led1202.c
> >
> > diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> > index 05e6af88b88c..c65f2b1bbe30 100644
> > --- a/drivers/leds/Kconfig
> > +++ b/drivers/leds/Kconfig
> > @@ -899,6 +899,16 @@ config LEDS_LM36274
> > Say Y to enable the LM36274 LED driver for TI LMU devices.
> > This supports the LED device LM36274.
> >
> > +config LEDS_LED1202
> > + tristate "LED Support for LED1202 I2C chips"
> > + depends on LEDS_CLASS
> > + depends on I2C
> > + depends on OF
> > + help
> > + Say Y to enable support for LEDs connected to LED1202
> > + LED driver chips accessed via the I2C bus.
> > + Supported devices include LED1202.
> > +
> > config LEDS_TPS6105X
> > tristate "LED support for TI TPS6105X"
> > depends on LEDS_CLASS
> > diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> > index effdfc6f1e95..80423fa8818e 100644
> > --- a/drivers/leds/Makefile
> > +++ b/drivers/leds/Makefile
> > @@ -36,6 +36,7 @@ obj-$(CONFIG_LEDS_IP30) += leds-ip30.o
> > obj-$(CONFIG_LEDS_IPAQ_MICRO) += leds-ipaq-micro.o
> > obj-$(CONFIG_LEDS_IS31FL319X) += leds-is31fl319x.o
> > obj-$(CONFIG_LEDS_IS31FL32XX) += leds-is31fl32xx.o
> > +obj-$(CONFIG_LEDS_LED1202) += leds-led1202.o
> > obj-$(CONFIG_LEDS_LM3530) += leds-lm3530.o
> > obj-$(CONFIG_LEDS_LM3532) += leds-lm3532.o
> > obj-$(CONFIG_LEDS_LM3533) += leds-lm3533.o
> > diff --git a/drivers/leds/leds-led1202.c b/drivers/leds/leds-led1202.c
> > new file mode 100644
> > index 000000000000..4e82f0e66168
> > --- /dev/null
> > +++ b/drivers/leds/leds-led1202.c
> > @@ -0,0 +1,617 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * Simple LED driver for ST LED1202 chip
>
> Just a simple 600+ line driver?
>
With you help maybe I can reduce it.
> ST as in STMicroelectronics?
>
> Please make that clear in the header and in the Kconfig entry.
>
Sure, will do.
> > + * Copyright (C) 2024 Remote-Tech Ltd. UK
> > + */
>
> New line here.
>
Noted, will add.
> > +#include <linux/module.h>
> > +#include <linux/string.h>
> > +#include <linux/ctype.h>
> > +#include <linux/leds.h>
> > +#include <linux/err.h>
> > +#include <linux/i2c.h>
> > +#include <linux/slab.h>
> > +#include <linux/gpio.h>
> > +#include <linux/delay.h>
> > +
> > +#define DRIVER_NAME "led-driver-1202"
>
> Remove this and user dev_err() instead.
>
> > +#define DRIVER_VERSION "0.0.1"
>
> Remove this entirely, it's useless.
>
Will do in v3.
> > +
> > +#define LL1202_MAX_LEDS 12
> > +
> > +#define LL1202_DEVICE_ID 0x00
> > +#define LL1202_DEV_ENABLE 0x01
> > +#define LL1202_CHAN_ENABLE_LOW 0x02
> > +#define LL1202_CHAN_ENABLE_HIGH 0x03
> > +#define LL1202_CONFIG_REG 0x04
> > +#define LL1202_ILED_REG0 0x09
> > +#define LL1202_PATTERN_REP 0x15
> > +#define LL1202_PATTERN_DUR 0x16
> > +#define LL1202_PATTERN_PWM 0x1E
> > +#define LL1202_CLOCK_REG 0xE0
>
> Tab out the values so they line up.
>
OK
> > +struct ll1202_led {
> > + struct led_classdev led_cdev;
> > + struct ll1202_chip *chip;
> > + int led_num;
> > + char name[32];
>
> Define this and all magic numbers.
>
Ok, there is some bitwise operations to form a 16bit from 8bit values.
And some magic number coming from the datasheet.
Those also?
> > + int is_active;
> > +};
> > +
> > +struct ll1202_chip {
> > + struct i2c_client *client;
> > + struct mutex lock;
> > + struct ll1202_led leds[LL1202_MAX_LEDS];
> > +};
> > +
> > +static struct ll1202_led *cdev_to_ll1202_led(struct led_classdev *cdev)
> > +{
> > + return container_of(cdev, struct ll1202_led, led_cdev);
> > +}
> > +
> > +static int ll1202_read_reg(struct ll1202_chip *chip, int reg, uint8_t *val)
> > +{
> > + int ret = i2c_smbus_read_byte_data(chip->client, reg);
>
> Separate the declaration and the function call.
>
Ok
> > +
> > + if (ret < 0)
> > + return ret;
> > +
> > + *val = (uint8_t)ret;
> > + return 0;
> > +}
> > +
> > +static int ll1202_write_reg(struct ll1202_chip *chip, int reg, uint8_t val)
>
> What's "ll"?
>
I reused some naming. Should it be led1202_ for all?
> > +{
> > + return i2c_smbus_write_byte_data(chip->client, reg, val);
> > +}
> > +
> > +static int ll1202_get_channel(struct device *dev)
> > +{
> > + struct device_node *np = dev->parent->of_node, *child;
> > + int err, ret = -1;
>
> What is -1?
Just negative return value. It's a helper function that returns the LED
channel number based on struct device.
If this is not appropiate or custom practice I can redo it, but I need some pointers
on where to look as "good" examples.
> > + for_each_child_of_node(np, child) {
> > + if (strncmp(dev->kobj.name,
> > + of_get_property(child, "label", NULL),
> > + strnlen(dev->kobj.name, MAX_INPUT)) == 0) {
>
> Pull all of these embedded functions out.
>
Ok.
> > + err = of_property_read_u32(child, "reg", &ret);
> > + if (err) {
> > + of_node_put(child);
> > + pr_err(DRIVER_NAME
> > + ": Failed to read property %s", child->name);
> > + return ret;
> > + }
> > + break;
> > + }
> > + }
> > + return ret;
> > +}
> > +
> > +static ssize_t ll1202_show_all_registers(struct device *dev,
> > + struct device_attribute *devattr,
> > + char *buf)
> > +{
> > + struct ll1202_chip *chip = dev_get_drvdata(dev);
> > + uint8_t reg_value = 0;
> > + int ret, i;
> > + char *bufp = buf;
> > +
> > + mutex_lock(&chip->lock);
> > +
> > + for (i = LL1202_DEVICE_ID; i <= LL1202_CLOCK_REG; i++) {
> > + ret = ll1202_read_reg(chip, i, ®_value);
> > + if (ret != 0)
> > + dev_err(&chip->client->dev,
> > + "Reading register [0x%x] failed.\n", i);
> > +
> > + bufp += snprintf(bufp, PAGE_SIZE, "Addr[0x%x] = 0x%x\n", i,
> > + reg_value);
> > + }
> > +
> > + mutex_unlock(&chip->lock);
> > + return strlen(buf);
> > +}
>
> Does this have any real world use?
>
A dump of all the registers with their values. I didn't add show/get functions for
all the registers.
Remove it?
> > +static ssize_t
> > +ll1202_show_patt_sequence_repetition(struct device *dev,
> > + struct device_attribute *attr, char *buf)
> > +{
> > + struct ll1202_chip *chip = dev_get_drvdata(dev);
> > + unsigned int ret;
> > + uint8_t reg_value;
> > + char *bufp = buf;
> > +
> > + mutex_lock(&chip->lock);
> > + ret = ll1202_read_reg(chip, LL1202_PATTERN_REP, ®_value);
> > + if (ret != 0)
> > + dev_err(&chip->client->dev, "Reading register [0x%x] failed\n", LL1202_PATTERN_REP);
> > + mutex_unlock(&chip->lock);
> > + bufp += snprintf(bufp, PAGE_SIZE,
> > + "Pattern sequence register, repetition value = %d (times)\n",
> > + reg_value);
> > + return strlen(buf);
> > +}
> > +
> > +static ssize_t
> > +ll1202_store_patt_sequence_repetition(struct device *dev,
> > + struct device_attribute *attr,
> > + const char *buf, size_t count)
> > +{
> > + struct ll1202_chip *chip = dev_get_drvdata(dev);
> > + unsigned int ret;
> > + unsigned long duration;
> > +
> > + if (!count)
> > + return -EINVAL;
> > +
> > + ret = kstrtoul(buf, 10, &duration);
> > + if (ret) {
> > + dev_err(&chip->client->dev, "sscanf failed with error :%d\n",
> > + ret);
> > + return ret;
> > + }
> > +
> > + mutex_lock(&chip->lock);
> > + ret = ll1202_write_reg(chip, LL1202_PATTERN_REP, duration);
> > + if (ret != 0)
> > + dev_err(&chip->client->dev, "Writing register [0x%x] failed\n",
> > + LL1202_PATTERN_REP);
> > + mutex_unlock(&chip->lock);
> > + return count;
> > +}
> > +
> > +static int ll1202_prescalar_to_miliamps(uint8_t reg_value)
> > +{
> > + return reg_value * 20 / 255;
>
> Define _all_ magic numbers.
>
Ok, will be done in v3
> > +}
> > +
> > +static int ll1202_prescalar_to_miliseconds(uint8_t reg_value)
> > +{
> > + return reg_value * 5660 / 255;
> > +}
> > +
> > +static ssize_t ll1202_show_channel_mA_current(struct device *dev,
> > + struct device_attribute *attr,
> > + char *buf)
> > +{
> > + struct ll1202_chip *chip = dev_get_drvdata(dev->parent);
> > + unsigned int ret;
> > + uint8_t reg_value;
> > + char *bufp = buf;
> > + int led_num = ll1202_get_channel(dev);
> > +
> > + if (led_num < 0 || led_num >= LL1202_MAX_LEDS) {
> > + dev_err(&chip->client->dev,
> > + "Invalid register [0x%x] (out of range)\n",
> > + led_num);
> > + }
> > + mutex_lock(&chip->lock);
> > + ret = ll1202_read_reg(chip, LL1202_ILED_REG0 + led_num, ®_value);
> > + if (ret != 0)
> > + dev_err(&chip->client->dev, "Reading analog dimming register [0x%x] failed\n",
> > + led_num);
> > + mutex_unlock(&chip->lock);
> > + bufp += snprintf(bufp, PAGE_SIZE, "Channel[%d] = %d mA\n", led_num,
> > + ll1202_prescalar_to_miliamps(reg_value));
> > + return strlen(buf);
>
> Space out the code properly - this is really tough to read.
>
Ok.. with or without the help of the IDE, it shall be done
> > +}
> > +
> > +static int ll1202_channel_activate(struct ll1202_led *led)
> > +{
> > + struct ll1202_chip *chip;
> > + uint8_t reg_chan_low, reg_chan_high;
> > + int ret = 0;
> > +
> > + chip = led->chip;
> > + if (led->is_active) {
>
> Reverse this logic and unindent this block.
>
Sorry, I need some more details on what I need to do here.
> > + mutex_lock(&chip->lock);
> > +
> > + ret = ll1202_read_reg(chip, LL1202_CHAN_ENABLE_LOW,
> > + ®_chan_low);
> > + if (ret < 0) {
> > + dev_err(&chip->client->dev,
> > + "Failed reading register [0x%x]\n", LL1202_CHAN_ENABLE_LOW);
> > + }
> > +
> > + ret = ll1202_read_reg(chip, LL1202_CHAN_ENABLE_HIGH,
> > + ®_chan_high);
> > + if (ret < 0) {
> > + dev_err(&chip->client->dev,
> > + "Failed reading register [0x%x]\n", LL1202_CHAN_ENABLE_HIGH);
> > + }
> > +
> > + reg_chan_low = reg_chan_low | BIT(led->led_num);
> > + ret = ll1202_write_reg(chip, LL1202_CHAN_ENABLE_LOW,
> > + reg_chan_low);
> > + if (ret < 0) {
> > + dev_err(&chip->client->dev,
> > + "Failed writing to register [0x%x]\n", LL1202_CHAN_ENABLE_LOW);
> > + }
> > + reg_chan_high = reg_chan_high | (BIT(led->led_num) >> 7);
> > + ret = ll1202_write_reg(chip, LL1202_CHAN_ENABLE_HIGH,
> > + reg_chan_high);
> > + if (ret < 0) {
> > + dev_err(&chip->client->dev,
> > + "Failed writing to register [0x%x]\n", LL1202_CHAN_ENABLE_HIGH);
> > + }
>
> Provide a comment as to why this cycle needs to be done twice.
I will paste the description from the datasheet in v3
>
> > + mutex_unlock(&chip->lock);
> > + }
> > + return ret;
> > +}
> > +
> > +#define LL1202_PWM_PATTERN_ATTR(pattern) \
>
> No chance!
>
> Where else do you see code like this?
>
The driver version is the one used for our custom f1c200s board.
It's a customization of the lctech,pi-f1c200s.
The kernel version provided by the SoC vendor is 5.2.0.
https://elixir.bootlin.com/linux/v5.2/source/drivers/leds/leds-bd2802.c
line 317
> > + static ssize_t ll1202_show_pwm_pattern##pattern( \
> > + struct device *dev, struct device_attribute *attr, char *buf) \
> > + { \
> > + struct ll1202_chip *chip = dev_get_drvdata(dev->parent); \
> > + uint8_t duration = 0; \
> > + uint8_t reg_value_l = 0; \
> > + uint8_t reg_value_h = 0; \
> > + uint16_t reg_value = 0; \
> > + int ret; \
> > + char *bufp = buf; \
> > + int led_num = ll1202_get_channel(dev); \
> > + if (led_num < 0 || led_num >= LL1202_MAX_LEDS) { \
> > + dev_err(&chip->client->dev, \
> > + "Invalid register [0x%x] (out of range)\n", \
> > + led_num); \
> > + } \
> > + mutex_lock(&chip->lock); \
> > + ret = ll1202_read_reg( \
> > + chip, \
> > + (LL1202_PATTERN_PWM + (led_num * 2) + 0x18 * pattern), \
> > + ®_value_l); \
> > + if (ret != 0) \
> > + dev_err(&chip->client->dev, \
> > + "Reading pattern PWM register [0x%x] failed\n", led_num); \
> > + ret = ll1202_read_reg(chip, \
> > + (LL1202_PATTERN_PWM + 0x1 + \
> > + (led_num * 2) + 0x18 * pattern), \
> > + ®_value_h); \
> > + if (ret != 0) \
> > + dev_err(&chip->client->dev, \
> > + "Reading pattern PWM register [0x%x] failed\n", led_num); \
> > + reg_value = (uint16_t)reg_value_h << 8 | reg_value_l; \
> > + ret = ll1202_read_reg(chip, (LL1202_PATTERN_DUR + pattern), \
> > + &duration); \
> > + if (ret != 0) \
> > + dev_err(&chip->client->dev, \
> > + "Reading pattern durating register [0x%x] failed\n", led_num); \
> > + bufp += snprintf( \
> > + bufp, PAGE_SIZE, \
> > + "Pattern[%d][cs%d]: PWM = 0x%03X; DURATION = %d ms\n", \
> > + pattern, led_num, reg_value, \
> > + ll1202_prescalar_to_miliseconds(duration)); \
> > + mutex_unlock(&chip->lock); \
> > + return strlen(buf); \
> > + } \
> > + static ssize_t ll1202_store_pwm_pattern##pattern( \
> > + struct device *dev, struct device_attribute *attr, \
> > + const char *buf, size_t count) \
> > + { \
> > + struct ll1202_chip *chip = dev_get_drvdata(dev->parent); \
> > + unsigned int ret, reg_value; \
> > + unsigned long duration; \
> > + char buf_u8[16]; \
> > + uint8_t reg_value_l = 0; \
> > + uint8_t reg_value_h = 0; \
> > + int led_num = ll1202_get_channel(dev); \
> > + if (led_num < 0 || led_num >= LL1202_MAX_LEDS) { \
> > + dev_err(&chip->client->dev, \
> > + "Invalid register [0x%x] (out of range)\n", \
> > + led_num); \
> > + return count; \
> > + } \
> > + if (!count) \
> > + return -EINVAL; \
> > + ret = sscanf(buf, "%X %s", ®_value, buf_u8); \
> > + if (ret == 0) { \
> > + dev_err(&chip->client->dev, \
> > + "sscanf failed with error :%d\n", ret); \
> > + return ret; \
> > + } \
> > + ret = kstrtoul(buf_u8, 10, &duration); \
> > + if (ret) \
> > + return ret; \
> > + reg_value_l = (uint8_t)reg_value; \
> > + reg_value_h = (uint8_t)(reg_value >> 8); \
> > + mutex_lock(&chip->lock); \
> > + ret = ll1202_write_reg( \
> > + chip, \
> > + (LL1202_PATTERN_PWM + (led_num * 2) + 0x18 * pattern), \
> > + (uint8_t)reg_value_l); \
> > + if (ret != 0) \
> > + dev_err(&chip->client->dev, \
> > + "Writing to register [0x%x] failed, value %d\n", \
> > + LL1202_PATTERN_PWM + (led_num * 2) + \
> > + 0x18 * pattern, \
> > + reg_value_l); \
> > + ret = ll1202_write_reg(chip, \
> > + (LL1202_PATTERN_PWM + 0x1 + \
> > + (led_num * 2) + 0x18 * pattern), \
> > + (uint8_t)reg_value_h); \
> > + if (ret != 0) \
> > + dev_err(&chip->client->dev, \
> > + "Writing to register [0x%x] failed, value %d\n", \
> > + (LL1202_PATTERN_PWM + 0x1 + (led_num * 2) + \
> > + 0x18 * pattern), \
> > + reg_value_h); \
> > + ret = ll1202_write_reg(chip, (LL1202_PATTERN_DUR + pattern), \
> > + (u8)duration); \
> > + if (ret != 0) \
> > + dev_err(&chip->client->dev, \
> > + "Writing to register [0x%x] failed, value %d\n", \
> > + (LL1202_PATTERN_DUR + pattern), (u8)duration); \
> > + ret = ll1202_write_reg(chip, LL1202_CONFIG_REG, \
> > + (0xC0 | pattern)); \
> > + if (ret != 0) { \
> > + dev_err(&chip->client->dev, \
> > + "Failed writing to reg [0x%x]\n", LL1202_CONFIG_REG); \
> > + } \
> > + mutex_unlock(&chip->lock); \
> > + ll1202_channel_activate(&chip->leds[led_num]); \
> > + return count; \
> > + } \
> > + static struct device_attribute dev_attr_led_pwm_pattern##pattern = { \
> > + .attr = { \
> > + .name = __stringify(pwm_pattern##pattern), \
> > + .mode = 00444 | 00200, \
> > + }, \
> > + .show = ll1202_show_pwm_pattern##pattern, \
> > + .store = ll1202_store_pwm_pattern##pattern, \
> > +}
> > +
> > +LL1202_PWM_PATTERN_ATTR(0);
> > +LL1202_PWM_PATTERN_ATTR(1);
> > +LL1202_PWM_PATTERN_ATTR(2);
> > +LL1202_PWM_PATTERN_ATTR(3);
> > +LL1202_PWM_PATTERN_ATTR(4);
> > +LL1202_PWM_PATTERN_ATTR(5);
> > +LL1202_PWM_PATTERN_ATTR(6);
> > +LL1202_PWM_PATTERN_ATTR(7);
>
> We already have global helpers for this type of thing.
>
Ok, could you please point me to the file/link?
> > +static DEVICE_ATTR(led_device_regsdump, 00444, ll1202_show_all_registers,
> > + NULL);
> > +static DEVICE_ATTR(patt_sequence_repetition, 00444 | 00200,
> > + ll1202_show_patt_sequence_repetition,
> > + ll1202_store_patt_sequence_repetition);
> > +static DEVICE_ATTR(current_mA, 00444, ll1202_show_channel_mA_current, NULL);
> > +
> > +static struct attribute *led_attrs[] = {
> > + &dev_attr_led_device_regsdump.attr,
> > + &dev_attr_patt_sequence_repetition.attr,
> > + NULL,
> > +};
> > +
> > +static struct attribute *led_group_attrs[] = {
> > + &dev_attr_led_pwm_pattern0.attr, &dev_attr_led_pwm_pattern1.attr,
> > + &dev_attr_led_pwm_pattern2.attr, &dev_attr_led_pwm_pattern3.attr,
> > + &dev_attr_led_pwm_pattern4.attr, &dev_attr_led_pwm_pattern5.attr,
> > + &dev_attr_led_pwm_pattern6.attr, &dev_attr_led_pwm_pattern7.attr,
> > + &dev_attr_current_mA.attr, NULL,
> > +};
> > +
> > +static struct attribute_group attr_group = {
> > + .attrs = led_attrs,
> > +};
> > +
> > +static struct attribute_group attr_pat_group = {
> > + .attrs = led_group_attrs,
> > +};
> > +
> > +static const struct attribute_group *ll1202_groups[] = { &attr_pat_group,
> > + NULL };
> > +
> > +static void ll1202_brightness_set(struct led_classdev *led_cdev,
> > + enum led_brightness value)
> > +{
> > + struct ll1202_led *led = cdev_to_ll1202_led(led_cdev);
> > + struct ll1202_chip *chip = led->chip;
> > + int ret;
> > +
> > + mutex_lock(&chip->lock);
> > + ret = ll1202_write_reg(chip, LL1202_ILED_REG0 + led->led_num, value);
> > + if (ret != 0)
> > + dev_err(&chip->client->dev, "Reading register [0x%x] failed\n",
> > + LL1202_ILED_REG0 + led->led_num);
> > + mutex_unlock(&chip->lock);
> > +}
> > +
> > +static enum led_brightness ll1202_brightness_get(struct led_classdev *led_cdev)
> > +{
> > + struct ll1202_led *led = cdev_to_ll1202_led(led_cdev);
> > + struct ll1202_chip *chip = led->chip;
> > + uint8_t reg_value;
> > + int ret;
> > +
> > + mutex_lock(&chip->lock);
> > + ret = ll1202_read_reg(chip, LL1202_ILED_REG0 + led->led_num,
> > + ®_value);
> > + if (ret != 0)
> > + dev_err(&chip->client->dev, "Reading register [0x%x] failed\n",
> > + LL1202_ILED_REG0 + led->led_num);
> > +
> > + mutex_unlock(&chip->lock);
> > + return reg_value;
> > +}
> > +
> > +static int ll1202_dt_init(struct ll1202_chip *chip)
> > +{
> > + struct device_node *np = chip->client->dev.of_node, *child;
> > + struct ll1202_led *led;
> > + int err, reg;
> > +
> > + for_each_child_of_node(np, child) {
> > + err = of_property_read_u32(child, "reg", ®);
> > + if (err) {
> > + of_node_put(child);
> > + pr_err(DRIVER_NAME ": Failed to get child node");
> > + return err;
> > + }
> > + if (reg < 0 || reg >= LL1202_MAX_LEDS) {
> > + of_node_put(child);
> > + pr_err(DRIVER_NAME ": Invalid register value [0x%x] (out of range)", reg);
> > + return -EINVAL;
> > + }
> > +
> > + led = &chip->leds[reg];
> > + led->led_cdev.name = of_get_property(child, "label", NULL) ?:
> > + child->name;
> > +
> > + err = of_property_read_u32(child, "active", &led->is_active);
> > + if (err) {
> > + of_node_put(child);
> > + pr_err(DRIVER_NAME ": Failed to get child node");
> > + return err;
> > + }
> > +
> > + led->led_cdev.brightness_set = ll1202_brightness_set;
> > + led->led_cdev.brightness_get = ll1202_brightness_get;
> > + led->led_cdev.groups = ll1202_groups;
> > + }
> > + return 0;
> > +}
> > +
> > +static int ll1202_setup(struct ll1202_chip *chip)
> > +{
> > + int ret;
> > +
> > + mutex_lock(&chip->lock);
> > + ret = ll1202_write_reg(chip, LL1202_DEV_ENABLE, 0x1);
> > + if (ret < 0) {
> > + dev_err(&chip->client->dev, "Failed writing to register [0x%x]\n",
> > + LL1202_DEV_ENABLE);
> > + }
> > + mutex_unlock(&chip->lock);
> > + usleep_range(6500, 10000);
> > + mutex_lock(&chip->lock);
> > + ret = ll1202_write_reg(chip, LL1202_DEV_ENABLE, 0x80);
> > + if (ret < 0) {
> > + dev_err(&chip->client->dev, "Failed writing to register [0x%x]\n",
> > + LL1202_DEV_ENABLE);
> > + }
> > + mutex_unlock(&chip->lock);
> > + usleep_range(6500, 10000);
> > + mutex_lock(&chip->lock);
> > + ret = ll1202_write_reg(chip, LL1202_PATTERN_REP, 0xFF);
> > + if (ret < 0) {
> > + dev_err(&chip->client->dev, "Failed writing to register [0x%x]\n",
> > + LL1202_PATTERN_REP);
> > + return ret;
> > + }
> > + mutex_unlock(&chip->lock);
> > + return ret;
> > +}
> > +
> > +static int ll1202_probe(struct i2c_client *client)
> > +{
> > + struct ll1202_chip *chip;
> > + struct ll1202_led *led;
> > + int ret, err;
> > + int i;
> > +
> > + pr_info(DRIVER_NAME ": (I2C) " DRIVER_VERSION "\n");
> > +
> > + if (!i2c_check_functionality(client->adapter,
> > + I2C_FUNC_SMBUS_BYTE_DATA)) {
> > + dev_err(&client->dev, "SMBUS Byte Data not Supported\n");
> > + return -EIO;
> > + }
> > +
> > + chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
> > + if (!chip)
> > + return -ENOMEM;
> > +
> > + i2c_set_clientdata(client, chip);
> > +
> > + mutex_init(&chip->lock);
> > + chip->client = client;
> > +
> > + /* Device tree setup */
> > + ret = ll1202_dt_init(chip);
> > + if (ret < 0)
> > + goto exit;
> > +
> > + /* Configuration setup */
> > + ret = ll1202_setup(chip);
> > + if (ret < 0)
> > + goto exit;
> > +
> > + for (i = 0; i < LL1202_MAX_LEDS; i++) {
> > + led = &chip->leds[i];
> > + led->chip = chip;
> > + led->led_num = i;
> > + if (led->is_active) {
> > + err = led_classdev_register(&client->dev,
> > + &led->led_cdev);
> > + if (err < 0) {
> > + pr_err(DRIVER_NAME
> > + ": Failed to register LED class dev");
> > + goto exit;
> > + }
> > + }
> > + }
> > +
> > + ret = sysfs_create_group(&client->dev.kobj, &attr_group);
> > + if (ret) {
> > + dev_err(&client->dev,
> > + "Failed to create sysfs group for ll1202\n");
> > + goto err_setup;
> > + }
> > +
> > + return 0;
> > +
> > +err_setup:
> > + for (i = 0; i < LL1202_MAX_LEDS; i++)
> > + led_classdev_unregister(&chip->leds[i].led_cdev);
> > +exit:
> > + mutex_destroy(&chip->lock);
> > + devm_kfree(&client->dev, chip);
> > + return ret;
> > +}
> > +
> > +static void ll1202_remove(struct i2c_client *client)
> > +{
> > + struct ll1202_chip *dev = i2c_get_clientdata(client);
> > + int i;
> > +
> > + for (i = 0; i < LL1202_MAX_LEDS; i++)
> > + led_classdev_unregister(&dev->leds[i].led_cdev);
> > +
> > + sysfs_remove_group(&client->dev.kobj, &attr_group);
> > +
> > + mutex_destroy(&dev->lock);
> > + devm_kfree(&client->dev, dev->leds);
> > + devm_kfree(&client->dev, dev);
> > +}
> > +
> > +static const struct i2c_device_id ll1202_id[] = {
> > + { DRIVER_NAME "-i2c", 0 },
> > + {}
> > +};
> > +
> > +MODULE_DEVICE_TABLE(i2c, ll1202_id);
> > +
> > +static const struct of_device_id ll1202_dt_ids[] = {
> > + {
> > + .compatible = "st,led1202",
> > + },
> > +};
> > +
> > +MODULE_DEVICE_TABLE(of, ll1202_dt_ids);
> > +
> > +static struct i2c_driver ll1202_driver = {
> > + .driver = {
> > + .name = "ll1202",
> > + .of_match_table = of_match_ptr(ll1202_dt_ids),
> > + },
> > + .probe = ll1202_probe,
> > + .remove = ll1202_remove,
> > + .id_table = ll1202_id,
> > +};
> > +
> > +module_i2c_driver(ll1202_driver);
> > +
> > +MODULE_AUTHOR("Remote Tech LTD");
> > +MODULE_DESCRIPTION("LED1202 : 12-channel constant current LED driver");
> > +MODULE_LICENSE("GPL");
> > --
> > 2.25.1
> >
Thank you Lee for the review!
Kind regards,
Vicentiu
>
> --
> Lee Jones [李琼斯]
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