Messages in this thread | | | Date | Wed, 24 Apr 2024 16:55:26 +0100 | Subject | Re: [PATCH 02/10] pwm: Add SI-EN SN3112 PWM support | From | Bryan O'Donoghue <> |
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On 24/04/2024 16:29, Xilin Wu via B4 Relay wrote: > From: Junhao Xie <bigfoot@classfun.cn> > > Add a new driver for the SI-EN SN3112 12-channel 8-bit PWM LED controller. > > Signed-off-by: Junhao Xie <bigfoot@classfun.cn> > --- > drivers/pwm/Kconfig | 10 ++ > drivers/pwm/Makefile | 1 + > drivers/pwm/pwm-sn3112.c | 336 +++++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 347 insertions(+) > > diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig > index 1dd7921194f5..e21c37c7991e 100644 > --- a/drivers/pwm/Kconfig > +++ b/drivers/pwm/Kconfig > @@ -553,6 +553,16 @@ config PWM_SL28CPLD > To compile this driver as a module, choose M here: the module > will be called pwm-sl28cpld. > > +config PWM_SN3112 > + tristate "SI-EN SN3112 PWM driver" > + depends on I2C > + select REGMAP_I2C > + help > + Generic PWM framework driver for SI-EN SN3112 LED controller. > + > + To compile this driver as a module, choose M here: the module > + will be called pwm-sn3112. > + > config PWM_SPEAR > tristate "STMicroelectronics SPEAr PWM support" > depends on PLAT_SPEAR || COMPILE_TEST > diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile > index 90913519f11a..6aab2d113159 100644 > --- a/drivers/pwm/Makefile > +++ b/drivers/pwm/Makefile > @@ -50,6 +50,7 @@ obj-$(CONFIG_PWM_RZ_MTU3) += pwm-rz-mtu3.o > obj-$(CONFIG_PWM_SAMSUNG) += pwm-samsung.o > obj-$(CONFIG_PWM_SIFIVE) += pwm-sifive.o > obj-$(CONFIG_PWM_SL28CPLD) += pwm-sl28cpld.o > +obj-$(CONFIG_PWM_SN3112) += pwm-sn3112.o > obj-$(CONFIG_PWM_SPEAR) += pwm-spear.o > obj-$(CONFIG_PWM_SPRD) += pwm-sprd.o > obj-$(CONFIG_PWM_STI) += pwm-sti.o > diff --git a/drivers/pwm/pwm-sn3112.c b/drivers/pwm/pwm-sn3112.c > new file mode 100644 > index 000000000000..38ef948602a3 > --- /dev/null > +++ b/drivers/pwm/pwm-sn3112.c > @@ -0,0 +1,336 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Driver for SN3112 12-channel 8-bit PWM LED controller > + * > + * Copyright (c) 2024 Junhao Xie <bigfoot@classfun.cn> > + * > + */ > + > +#include <linux/i2c.h> > +#include <linux/module.h> > +#include <linux/mutex.h> > +#include <linux/platform_device.h> > +#include <linux/pwm.h> > +#include <linux/regmap.h> > +#include <linux/delay.h> > +#include <linux/gpio/consumer.h> > +#include <linux/regulator/consumer.h>
Includes should be alphabetised
> + > +#define SN3112_CHANNELS 12 > +#define SN3112_REG_ENABLE 0x00 > +#define SN3112_REG_PWM_VAL 0x04 > +#define SN3112_REG_PWM_EN 0x13 > +#define SN3112_REG_APPLY 0x16 > +#define SN3112_REG_RESET 0x17 > + > +struct sn3112 { > + struct device *pdev; > + struct regmap *regmap; > + struct mutex lock; > + struct regulator *vdd; > + uint8_t pwm_val[SN3112_CHANNELS]; > + uint8_t pwm_en_reg[3]; > + bool pwm_en[SN3112_CHANNELS]; > +#if IS_ENABLED(CONFIG_GPIOLIB) > + struct gpio_desc *sdb; > +#endif > +}; > + > +static int sn3112_write_reg(struct sn3112 *priv, unsigned int reg, > + unsigned int val) > +{ > + int err; > + > + dev_dbg(priv->pdev, "request regmap_write 0x%x 0x%x\n", reg, val); > + err = regmap_write(priv->regmap, reg, val); > + if (err) > + dev_warn_ratelimited( > + priv->pdev, > + "regmap_write to register 0x%x failed: %pe\n", reg, > + ERR_PTR(err));
Multi-line should be encapsulated in {}
if (err) { stuff goes here }
> + return err; > +} > + > +static int sn3112_set_en_reg(struct sn3112 *priv, unsigned int channel, > + bool enabled, bool write) > +{ > + unsigned int reg, bit; > + > + if (channel >= SN3112_CHANNELS) > + return -EINVAL; > + > + /* LED_EN1: BIT5:BIT3 = OUT3:OUT1 */ > + if (channel >= 0 && channel <= 2) > + reg = 0, bit = channel + 3; > + /* LED_EN2: BIT5:BIT0 = OUT9:OUT4 */ > + else if (channel >= 3 && channel <= 8) > + reg = 1, bit = channel - 3; > + /* LED_EN3: BIT2:BIT0 = OUT12:OUT10 */ > + else if (channel >= 9 && channel <= 11) > + reg = 2, bit = channel - 9; > + else > + return -EINVAL; > + > + dev_dbg(priv->pdev, "channel %u enabled %u\n", channel, enabled); > + dev_dbg(priv->pdev, "reg %u bit %u\n", reg, bit); > + if (enabled) > + set_bit(bit, (ulong *)&priv->pwm_en_reg[reg]); > + else > + clear_bit(bit, (ulong *)&priv->pwm_en_reg[reg]); > + dev_dbg(priv->pdev, "set enable reg %u to %u\n", reg, > + priv->pwm_en_reg[reg]); > + > + if (!write) > + return 0; newline > + return sn3112_write_reg(priv, SN3112_REG_PWM_EN + reg, > + priv->pwm_en_reg[reg]); > +} > + > +static int sn3112_set_val_reg(struct sn3112 *priv, unsigned int channel, > + uint8_t val, bool write) > +{ > + if (channel >= SN3112_CHANNELS) > + return -EINVAL; newline > + priv->pwm_val[channel] = val; > + dev_dbg(priv->pdev, "set value reg %u to %u\n", channel, > + priv->pwm_val[channel]); > + > + if (!write) > + return 0; newline > + return sn3112_write_reg(priv, SN3112_REG_PWM_VAL + channel, > + priv->pwm_val[channel]); > +} > + > +static int sn3112_write_all(struct sn3112 *priv) > +{ > + int i, ret; > + > + /* regenerate enable register values */ > + for (i = 0; i < SN3112_CHANNELS; i++) { > + ret = sn3112_set_en_reg(priv, i, priv->pwm_en[i], false); > + if (ret != 0) > + return ret; > + } > + > + /* use random value to clear all registers */ > + ret = sn3112_write_reg(priv, SN3112_REG_RESET, 0x66); > + if (ret != 0) > + return ret; > + > + /* set software enable register */ > + ret = sn3112_write_reg(priv, SN3112_REG_ENABLE, 1); > + if (ret != 0) > + return ret; > + > + /* rewrite pwm value register */ > + for (i = 0; i < SN3112_CHANNELS; i++) { > + ret = sn3112_write_reg(priv, SN3112_REG_PWM_VAL + i, > + priv->pwm_val[i]); > + if (ret != 0) > + return ret; > + } > + > + /* rewrite pwm enable register */ > + for (i = 0; i < 3; i++) { > + ret = sn3112_write_reg(priv, SN3112_REG_PWM_EN + i, > + priv->pwm_en_reg[i]); > + if (ret != 0) > + return ret; > + } > + > + /* use random value to apply changes */ > + ret = sn3112_write_reg(priv, SN3112_REG_APPLY, 0x66); > + if (ret != 0) > + return ret; > + > + dev_dbg(priv->pdev, "reinitialized\n"); > + return 0; > +} > + > +static int sn3112_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) > +{ > + struct sn3112 *priv = pwmchip_get_drvdata(chip); > + > + if (pwm->hwpwm >= SN3112_CHANNELS) > + return -EINVAL; > + > + dev_dbg(priv->pdev, "sn3112 request channel %u\n", pwm->hwpwm); > + pwm->args.period = 1000000; newline > + return 0; > +} > + > +static int sn3112_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, > + const struct pwm_state *state) > +{ > + u64 val = 0; > + struct sn3112 *priv = pwmchip_get_drvdata(chip); > + > + if (pwm->hwpwm >= SN3112_CHANNELS) > + return -EINVAL; > + > + if (state->polarity != PWM_POLARITY_NORMAL) > + return -EINVAL; > + > + if (state->period <= 0) > + return -EINVAL; > + > + val = mul_u64_u64_div_u64(state->duty_cycle, 0xff, state->period); > + dev_dbg(priv->pdev, "duty_cycle %llu period %llu\n", state->duty_cycle, > + state->period); > + dev_dbg(priv->pdev, "set channel %u value to %llu\n", pwm->hwpwm, val); > + dev_dbg(priv->pdev, "set channel %u enabled to %u\n", pwm->hwpwm, > + state->enabled); > + > + mutex_lock(&priv->lock); > + sn3112_set_en_reg(priv, pwm->hwpwm, state->enabled, true); > + sn3112_set_val_reg(priv, pwm->hwpwm, val, true); > + sn3112_write_reg(priv, SN3112_REG_APPLY, 0x66); > + mutex_unlock(&priv->lock); > + > + return 0; > +} > + > +static const struct pwm_ops sn3112_pwm_ops = { > + .apply = sn3112_pwm_apply, > + .request = sn3112_pwm_request, > +}; > + > +static const struct regmap_config sn3112_regmap_i2c_config = { > + .reg_bits = 8, > + .val_bits = 8, > + .max_register = 24, > + .cache_type = REGCACHE_NONE, > +}; > + > +static int sn3112_pwm_probe(struct i2c_client *client) > +{ > + struct pwm_chip *chip; > + struct sn3112 *priv; > + int ret, i; > + > + dev_dbg(&client->dev, "probing\n"); You can probably live without that in an upstream driver..
> + chip = devm_pwmchip_alloc(&client->dev, SN3112_CHANNELS, sizeof(*priv)); > + if (IS_ERR(chip)) > + return PTR_ERR(chip); > + priv = pwmchip_get_drvdata(chip); > + priv->pdev = &client->dev; > + > + /* initialize sn3112 (chip does not support read command) */ > + for (i = 0; i < SN3112_CHANNELS; i++) > + priv->pwm_en[i] = false; > + for (i = 0; i < SN3112_CHANNELS; i++) > + priv->pwm_val[i] = 0; > + for (i = 0; i < 3; i++) > + priv->pwm_en_reg[i] = 0;
Why does pwm_val have a define to constrain the array but pwm_en_reg have hard-coded 3 ?
Suggest using a #define for the 3 value for consistency / extensibility.
> + > + /* enable sn5112 power vdd */ > + priv->vdd = devm_regulator_get(priv->pdev, "vdd"); > + if (IS_ERR(priv->vdd)) { > + ret = PTR_ERR(priv->vdd); > + dev_err(priv->pdev, "Unable to get vdd regulator: %d\n", ret); > + return ret; > + } > + > +#if IS_ENABLED(CONFIG_GPIOLIB) > + /* sn5112 hardware shutdown pin */ > + priv->sdb = devm_gpiod_get_optional(priv->pdev, "sdb", GPIOD_OUT_LOW); > + if (PTR_ERR(priv->sdb) == -EPROBE_DEFER) > + return -EPROBE_DEFER; > +#endif > + > + /* enable sn5112 power vdd */ > + ret = regulator_enable(priv->vdd); > + if (ret < 0) { > + dev_err(priv->pdev, "Unable to enable regulator: %d\n", ret); > + return ret; > + } > + > + priv->regmap = devm_regmap_init_i2c(client, &sn3112_regmap_i2c_config); > + if (IS_ERR(priv->regmap)) { > + ret = PTR_ERR(priv->regmap); > + dev_err(priv->pdev, "Failed to initialize register map: %d\n", > + ret); > + return ret; > + } > + > + i2c_set_clientdata(client, chip); > + mutex_init(&priv->lock); > + > + chip->ops = &sn3112_pwm_ops; > + ret = pwmchip_add(chip); > + if (ret < 0) > + return ret; > + > +#if IS_ENABLED(CONFIG_GPIOLIB) > + /* disable hardware shutdown pin */ > + if (priv->sdb) > + gpiod_set_value(priv->sdb, 0); > +#endif > + > + /* initialize registers */ > + ret = sn3112_write_all(priv); > + if (ret != 0) { > + dev_err(priv->pdev, "Failed to initialize sn3112: %d\n", ret); > + return ret; > + } > + > + dev_info(&client->dev, > + "Found SI-EN SN3112 12-channel 8-bit PWM LED controller\n"); newline > + return 0; > +} > + > +static void sn3112_pwm_remove(struct i2c_client *client) > +{ > + struct pwm_chip *chip = i2c_get_clientdata(client); > + struct sn3112 *priv = pwmchip_get_drvdata(chip); > + > + dev_dbg(priv->pdev, "remove\n"); suggest dropping from both probe() and remove() > + > + /* set software enable register */ > + sn3112_write_reg(priv, SN3112_REG_ENABLE, 0); > + > + /* use random value to apply changes */ > + sn3112_write_reg(priv, SN3112_REG_APPLY, 0x66); > + > +#if IS_ENABLED(CONFIG_GPIOLIB) > + /* enable hardware shutdown pin */ > + if (priv->sdb) > + gpiod_set_value(priv->sdb, 1); > +#endif > + > + /* power-off sn5112 power vdd */ > + regulator_disable(priv->vdd); > + > + pwmchip_remove(chip); > +} > + > +static const struct i2c_device_id sn3112_id[] = { > + { "sn3112", 0 }, > + { /* sentinel */ }, > +}; > +MODULE_DEVICE_TABLE(i2c, sn3112_id); > + > +#ifdef CONFIG_OF > +static const struct of_device_id sn3112_dt_ids[] = { > + { .compatible = "si-en,sn3112-pwm", }, > + { /* sentinel */ } > +}; > +MODULE_DEVICE_TABLE(of, sn3112_dt_ids); > +#endif > + > +static struct i2c_driver sn3112_i2c_driver = { > + .driver = { > + .name = "sn3112-pwm", > + .of_match_table = of_match_ptr(sn3112_dt_ids), > + }, > + .probe = sn3112_pwm_probe, > + .remove = sn3112_pwm_remove, > + .id_table = sn3112_id, > +}; > + > +module_i2c_driver(sn3112_i2c_driver); > + > +MODULE_AUTHOR("BigfootACA <bigfoot@classfun.cn>"); BigFootACA not Xilin Wu ? > +MODULE_DESCRIPTION("PWM driver for SI-EN SN3112"); > +MODULE_LICENSE("GPL"); >
Also please consider the following checkpatch errors
WARNING: added, moved or deleted file(s), does MAINTAINERS need updating? #50: new file mode 100644
CHECK: struct mutex definition without comment #83: FILE: drivers/pwm/pwm-sn3112.c:29: + struct mutex lock;
CHECK: Prefer kernel type 'u8' over 'uint8_t' #85: FILE: drivers/pwm/pwm-sn3112.c:31: + uint8_t pwm_val[SN3112_CHANNELS];
CHECK: Prefer kernel type 'u8' over 'uint8_t' #86: FILE: drivers/pwm/pwm-sn3112.c:32: + uint8_t pwm_en_reg[3];
CHECK: Lines should not end with a '(' #101: FILE: drivers/pwm/pwm-sn3112.c:47: + dev_warn_ratelimited(
CHECK: Prefer kernel type 'u8' over 'uint8_t' #145: FILE: drivers/pwm/pwm-sn3112.c:91: + uint8_t val, bool write)
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