Hi David, i will test the driver on weekend. Some comments below > "David Rivshin (Allworx)" <drivshin.allworx@xxxxxxxxx> hat am 3. März 2016 um > 04:01 geschrieben: > > > From: David Rivshin <drivshin@xxxxxxxxxxx> > > The IS31FL32xx family of LED controllers are I2C devices with multiple > constant-current channels, each with independent 256-level PWM control. > > Datasheets: http://www.issi.com/US/product-analog-fxled-driver.shtml > > This has been tested on the IS31FL3236 and IS31FL3216, on an ARM > (TI am335x) platform. > > The programming paradigm of these devices is similar in the following > ways: > - All registers are 8 bit > - All LED control registers are write-only > - Each LED channel has a PWM register (0-255) > - PWM register writes are shadowed until an Update register is poked > - All have a concept of Software Shutdown, which disables output > > However, there are some differences in devices: > - 3236/3235 have a separate Control register for each LED, > (3218/3216 pack the enable bits into fewer registers) > - 3236/3235 have a per-channel current divisor setting > - 3236/3235 have a Global Control register that can turn off all LEDs > - 3216 is unique in a number of ways > - OUT9-OUT16 can be configured as GPIOs instead of LED controls > - LEDs can be programmed with an 8-frame animation, with > programmable delay between frames > - LEDs can be modulated by an input audio signal > - Max output current can be adjusted from 1/4 to 2x globally > - Has a Configuration register instead of a Shutdown register > > This driver currently only supports the base PWM control function > of these devices. The following features of these devices are not > implemented, although it should be possible to add them in the future: > - All devices are capable of going into a lower-power "software > shutdown" mode. > - The is31fl3236 and is31fl3235 can reduce the max output current > per-channel with a divisor of 1, 2, 3, or 4. > - The is31fl3216 can use some LED channels as GPIOs instead. > - The is31fl3216 can animate LEDs in hardware. > - The is31fl3216 can modulate LEDs according to an audio input. > - The is31fl3216 can reduce/increase max output current globally. > > Signed-off-by: David Rivshin <drivshin@xxxxxxxxxxx> > --- > > You may see two instances of this warning: > "passing argument 1 of 'of_property_read_string' discards 'const' > qualifier from pointer target type" > That is a result of of_property_read_string() taking a non-const > struct device_node pointer parameter. I have separately submitted a > patch to fix that [1], and a few related functions which had the same > issue. I'm hoping that will get into linux-next before this does, so > that the warnings never show up there. > > Changes from RFC: > - Removed max-brightness DT property. > - Refer to these devices as "LED controllers" in Kconfig. > - Removed redundant last sentence from Kconfig entry > - Removed unnecessary debug code. > - Do not set led_classdev.brightness to 0 explicitly, as it is > already initialized to 0 by devm_kzalloc(). > - Used of_property_read_string() instead of of_get_property(). > - Fail immediately on DT parsing error in a child node, rather than > continuing on with the non-faulty ones. > - Added additional comments for some things that might be non-obvious. > - Added constants for the location of the SSD bit in the SHUTDOWN > register, and the 3216's CONFIG register. > - Added special sw_shutdown_func for the 3216 device, as that bit > is in a different register, at a different position, and has reverse > polarity compared to all the other devices. > - Refactored is31fl32xx_init_regs() to separate out some logic into > is31fl32xx_reset_regs() and is31fl32xx_software_shutdown(). > > [1] https://lkml.org/lkml/2016/3/2/746 > > drivers/leds/Kconfig | 8 + > drivers/leds/Makefile | 1 + > drivers/leds/leds-is31fl32xx.c | 505 +++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 514 insertions(+) > create mode 100644 drivers/leds/leds-is31fl32xx.c > > diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig > index 1034696..9c63ba4 100644 > --- a/drivers/leds/Kconfig > +++ b/drivers/leds/Kconfig > @@ -580,6 +580,14 @@ config LEDS_SN3218 > This driver can also be built as a module. If so the module > will be called leds-sn3218. > > +config LEDS_IS31FL32XX > + tristate "LED support for ISSI IS31FL32XX I2C LED controller family" > + depends on LEDS_CLASS && I2C && OF > + help > + Say Y here to include support for ISSI IS31FL32XX LED controllers. > + They are I2C devices with multiple constant-current channels, each > + with independent 256-level PWM control. Is it worth to mention the module name here? > + > comment "LED driver for blink(1) USB RGB LED is under Special HID drivers > (HID_THINGM)" > > config LEDS_BLINKM > diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile > index 89c9b6f..3fdf313 100644 > --- a/drivers/leds/Makefile > +++ b/drivers/leds/Makefile > @@ -67,6 +67,7 @@ obj-$(CONFIG_LEDS_KTD2692) += leds-ktd2692.o > obj-$(CONFIG_LEDS_POWERNV) += leds-powernv.o > obj-$(CONFIG_LEDS_SEAD3) += leds-sead3.o > obj-$(CONFIG_LEDS_SN3218) += leds-sn3218.o > +obj-$(CONFIG_LEDS_IS31FL32XX) += leds-is31fl32xx.o > > # LED SPI Drivers > obj-$(CONFIG_LEDS_DAC124S085) += leds-dac124s085.o > diff --git a/drivers/leds/leds-is31fl32xx.c b/drivers/leds/leds-is31fl32xx.c > new file mode 100644 > index 0000000..49818f0 > --- /dev/null > +++ b/drivers/leds/leds-is31fl32xx.c > @@ -0,0 +1,505 @@ > +/* > + * linux/drivers/leds-is31fl32xx.c I think this is unnecessary. > + * > + * Driver for ISSI IS31FL32xx family of I2C LED controllers > + * > + * Copyright 2015 Allworx Corp. > + * > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + * > + * Datasheets: http://www.issi.com/US/product-analog-fxled-driver.shtml > + */ > + Shouldn't we include <linux/device.h> here? > +#include <linux/err.h> > +#include <linux/i2c.h> > +#include <linux/kernel.h> > +#include <linux/leds.h> > +#include <linux/module.h> > +#include <linux/of_platform.h> > + > +/* Used to indicate a device has no such register */ > +#define IS31FL32XX_REG_NONE 0xFF > + > +/* Software Shutdown bit in Shutdown Register */ > +#define IS31FL32XX_SHUTDOWN_SSD_ENABLE 0 > +#define IS31FL32XX_SHUTDOWN_SSD_DISABLE BIT(0) > + > +/* IS31FL3216 has a number of unique registers */ > +#define IS31FL3216_CONFIG_REG 0x00 > +#define IS31FL3216_LIGHTING_EFFECT_REG 0x03 > +#define IS31FL3216_CHANNEL_CONFIG_REG 0x04 > + > +/* Software Shutdown bit in 3216 Config Register */ > +#define IS31FL3216_CONFIG_SSD_ENABLE BIT(7) > +#define IS31FL3216_CONFIG_SSD_DISABLE 0 > + > +struct is31fl32xx_priv; > +struct is31fl32xx_led_data { > + struct led_classdev cdev; > + u8 channel; /* 1-based, max priv->cdef->channels */ > + struct is31fl32xx_priv *priv; > +}; > + > +struct is31fl32xx_priv { > + const struct is31fl32xx_chipdef *cdef; > + struct i2c_client *client; > + unsigned int num_leds; > + struct is31fl32xx_led_data leds[0]; > +}; > + > +/** > + * struct is31fl32xx_chipdef - chip-specific attributes > + * @channels : Number of LED channels > + * @shutdown_reg : address of Shutdown register (optional) > + * @pwm_update_reg : address of PWM Update register > + * @global_control_reg : address of Global Control register (optional) > + * @reset_reg : address of Reset register (optional) > + * @pwm_register_base : address of first PWM register > + * @pwm_registers_reversed: : true if PWM registers count down instead of up > + * @led_control_register_base : address of first LED control register > (optional) > + * @enable_bits_per_led_control_register: number of LEDs enable bits in each > + * @reset_func: : pointer to reset function > + * > + * For all optional register addresses, the sentinel value > %IS31FL32XX_REG_NONE > + * indicates that this chip has no such register. > + * > + * If non-NULL, @reset_func will be called during probing to set all > + * necessary registers to a known initialization state. This is needed > + * for chips that do not have a @reset_reg. > + * > + * @enable_bits_per_led_control_register must be >=1 if > + * @led_control_register_base != %IS31FL32XX_REG_NONE. > + */ > +struct is31fl32xx_chipdef { > + u8 channels; > + u8 shutdown_reg; > + u8 pwm_update_reg; > + u8 global_control_reg; > + u8 reset_reg; > + u8 pwm_register_base; > + bool pwm_registers_reversed; > + u8 led_control_register_base; > + u8 enable_bits_per_led_control_register; > + int (*reset_func)(struct is31fl32xx_priv *priv); > + int (*sw_shutdown_func)(struct is31fl32xx_priv *priv, bool enable); > +}; > + > +static const struct is31fl32xx_chipdef is31fl3236_cdef = { > + .channels = 36, > + .shutdown_reg = 0x00, > + .pwm_update_reg = 0x25, > + .global_control_reg = 0x4a, > + .reset_reg = 0x4f, > + .pwm_register_base = 0x01, > + .led_control_register_base = 0x26, > + .enable_bits_per_led_control_register = 1, > +}; > + > +static const struct is31fl32xx_chipdef is31fl3235_cdef = { > + .channels = 28, > + .shutdown_reg = 0x00, > + .pwm_update_reg = 0x25, > + .global_control_reg = 0x4a, > + .reset_reg = 0x4f, > + .pwm_register_base = 0x05, > + .led_control_register_base = 0x2a, > + .enable_bits_per_led_control_register = 1, > +}; > + > +static const struct is31fl32xx_chipdef is31fl3218_cdef = { > + .channels = 18, > + .shutdown_reg = 0x00, > + .pwm_update_reg = 0x16, > + .global_control_reg = IS31FL32XX_REG_NONE, > + .reset_reg = 0x17, > + .pwm_register_base = 0x01, > + .led_control_register_base = 0x13, > + .enable_bits_per_led_control_register = 6, > +}; > + > +static int is31fl3216_reset(struct is31fl32xx_priv *priv); > +static int is31fl3216_software_shutdown(struct is31fl32xx_priv *priv, > + bool enable); > +static const struct is31fl32xx_chipdef is31fl3216_cdef = { > + .channels = 16, > + .shutdown_reg = IS31FL32XX_REG_NONE, > + .pwm_update_reg = 0xB0, > + .global_control_reg = IS31FL32XX_REG_NONE, > + .reset_reg = IS31FL32XX_REG_NONE, > + .pwm_register_base = 0x10, > + .pwm_registers_reversed = true, > + .led_control_register_base = 0x01, > + .enable_bits_per_led_control_register = 8, > + .reset_func = is31fl3216_reset, > + .sw_shutdown_func = is31fl3216_software_shutdown, > +}; > + > +static int is31fl32xx_write(struct is31fl32xx_priv *priv, u8 reg, u8 val) > +{ > + int ret; > + > + dev_dbg(&priv->client->dev, "writing register 0x%02X=0x%02X", reg, val); > + > + ret = i2c_smbus_write_byte_data(priv->client, reg, val); > + if (ret) { > + dev_err(&priv->client->dev, > + "register write to 0x%02X failed (error %d)", > + reg, ret); > + } In case somebody use this driver as heartbeat and writing fails permanently the log will be flooded. > + return ret; > +} > + > +/* > + * Custom reset function for IS31FL3216 because it does not have a RESET > + * register the way that the other IS31FL32xx chips do. We don't bother > + * writing the GPIO and animation registers, because the registers we > + * do write ensure those will have no effect. > + */ > +static int is31fl3216_reset(struct is31fl32xx_priv *priv) > +{ > + unsigned int i; > + int ret; > + > + ret = is31fl32xx_write(priv, IS31FL3216_CONFIG_REG, > + IS31FL3216_CONFIG_SSD_ENABLE); > + if (ret) > + return ret; > + for (i = 0; i < priv->cdef->channels; i++) { > + ret = is31fl32xx_write(priv, priv->cdef->pwm_register_base+i, > + 0x00); > + if (ret) > + return ret; > + } > + ret = is31fl32xx_write(priv, priv->cdef->pwm_update_reg, 0); > + if (ret) > + return ret; > + ret = is31fl32xx_write(priv, IS31FL3216_LIGHTING_EFFECT_REG, 0x00); > + if (ret) > + return ret; > + ret = is31fl32xx_write(priv, IS31FL3216_CHANNEL_CONFIG_REG, 0x00); > + if (ret) > + return ret; > + > + return 0; > +} > + > +/* > + * Custom Software-Shutdown function for IS31FL3216 because it does not have > + * a SHUTDOWN register the way that the other IS31FL32xx chips do. > + * We don't bother doing a read/modify/write on the CONFIG register because > + * we only ever use a value of '0' for the other fields in that register. > + */ > +static int is31fl3216_software_shutdown(struct is31fl32xx_priv *priv, > + bool enable) > +{ > + u8 value = enable ? IS31FL3216_CONFIG_SSD_ENABLE : > + IS31FL3216_CONFIG_SSD_DISABLE; > + > + return is31fl32xx_write(priv, IS31FL3216_CONFIG_REG, value); > +} > + > +/* > + * NOTE: A mutex is not needed in this function because: > + * - All referenced data is read-only after probe() > + * - The I2C core has a mutex on to protect the bus > + * - There are no read/modify/write operations > + * - Intervening operations between the write of the PWM register > + * and the Update register are harmless. > + * > + * Example: > + * PWM_REG_1 write 16 > + * UPDATE_REG write 0 > + * PWM_REG_2 write 128 > + * UPDATE_REG write 0 > + * vs: > + * PWM_REG_1 write 16 > + * PWM_REG_2 write 128 > + * UPDATE_REG write 0 > + * UPDATE_REG write 0 > + * are equivalent. Poking the Update register merely applies all PWM > + * register writes up to that point. > + */ > +static int is31fl32xx_brightness_set(struct led_classdev *led_cdev, > + enum led_brightness brightness) > +{ > + const struct is31fl32xx_led_data *led_data = > + container_of(led_cdev, struct is31fl32xx_led_data, cdev); > + const struct is31fl32xx_chipdef *cdef = led_data->priv->cdef; > + u8 pwm_register_offset; > + int ret; > + > + dev_dbg(led_cdev->dev, "%s: %d\n", __func__, brightness); > + > + /* NOTE: led_data->channel is 1-based */ > + if (cdef->pwm_registers_reversed) > + pwm_register_offset = cdef->channels - led_data->channel; > + else > + pwm_register_offset = led_data->channel - 1; > + > + ret = is31fl32xx_write(led_data->priv, > + cdef->pwm_register_base + pwm_register_offset, > + brightness); > + if (ret) > + return ret; > + > + return is31fl32xx_write(led_data->priv, cdef->pwm_update_reg, 0); > +} > + > +static int is31fl32xx_reset_regs(struct is31fl32xx_priv *priv) > +{ > + const struct is31fl32xx_chipdef *cdef = priv->cdef; > + int ret; > + > + if (cdef->reset_reg != IS31FL32XX_REG_NONE) { > + ret = is31fl32xx_write(priv, cdef->reset_reg, 0); > + if (ret) > + return ret; > + } > + > + if (cdef->reset_func) > + return cdef->reset_func(priv); > + > + return 0; > +} > + > +static int is31fl32xx_software_shutdown(struct is31fl32xx_priv *priv, > + bool enable) > +{ > + const struct is31fl32xx_chipdef *cdef = priv->cdef; > + int ret; > + > + if (cdef->shutdown_reg != IS31FL32XX_REG_NONE) { > + u8 value = enable ? IS31FL32XX_SHUTDOWN_SSD_ENABLE : > + IS31FL32XX_SHUTDOWN_SSD_DISABLE; > + ret = is31fl32xx_write(priv, cdef->shutdown_reg, value); > + if (ret) > + return ret; > + } > + > + if (cdef->sw_shutdown_func) > + return cdef->sw_shutdown_func(priv, enable); > + > + return 0; > +} > + > +static int is31fl32xx_init_regs(struct is31fl32xx_priv *priv) > +{ > + const struct is31fl32xx_chipdef *cdef = priv->cdef; > + int ret; > + > + ret = is31fl32xx_reset_regs(priv); > + if (ret) > + return ret; > + > + /* > + * Set enable bit for all channels. > + * We will control state with PWM registers alone. > + */ > + if (cdef->led_control_register_base != IS31FL32XX_REG_NONE) { > + u8 value = > + GENMASK(cdef->enable_bits_per_led_control_register-1, 0); > + u8 num_regs = cdef->channels / > + cdef->enable_bits_per_led_control_register; > + int i; > + > + for (i = 0; i < num_regs; i++) { > + ret = is31fl32xx_write(priv, > + cdef->led_control_register_base+i, > + value); > + if (ret) > + return ret; > + } > + } > + > + ret = is31fl32xx_software_shutdown(priv, false); > + if (ret) > + return ret; > + > + if (cdef->global_control_reg != IS31FL32XX_REG_NONE) { > + ret = is31fl32xx_write(priv, cdef->global_control_reg, 0x00); > + if (ret) > + return ret; > + } > + > + return 0; > +} > + > +static inline size_t sizeof_is31fl32xx_priv(int num_leds) > +{ > + return sizeof(struct is31fl32xx_priv) + > + (sizeof(struct is31fl32xx_led_data) * num_leds); > +} > + > +static int is31fl32xx_parse_child_dt(const struct device *dev, > + const struct device_node *child, > + struct is31fl32xx_led_data *led_data) > +{ > + struct led_classdev *cdev = &led_data->cdev; > + int ret = 0; > + u32 reg; > + > + if (of_property_read_string(child, "label", &cdev->name)) > + cdev->name = child->name; > + > + ret = of_property_read_u32(child, "reg", ®); > + if (ret || reg < 1 || reg > led_data->priv->cdef->channels) { > + dev_err(dev, > + "Child node %s does not have a valid reg property\n", > + child->full_name); > + return -EINVAL; > + } > + led_data->channel = reg; > + > + of_property_read_string(child, "linux,default-trigger", > + &cdev->default_trigger); > + > + cdev->brightness_set_blocking = is31fl32xx_brightness_set; > + > + return 0; > +} > + > +static struct is31fl32xx_led_data *is31fl32xx_find_led_data( > + struct is31fl32xx_priv *priv, > + u8 channel) > +{ > + size_t i; > + > + for (i = 0; i < priv->num_leds; i++) { > + if (priv->leds[i].channel == channel) > + return &priv->leds[i]; > + } > + > + return NULL; > +} > + > +static int is31fl32xx_parse_dt(struct device *dev, > + struct is31fl32xx_priv *priv) > +{ > + struct device_node *child; > + int ret = 0; > + > + for_each_child_of_node(dev->of_node, child) { > + struct is31fl32xx_led_data *led_data = > + &priv->leds[priv->num_leds]; Maybe i missed something, but is it really protected against out of index access? > + const struct is31fl32xx_led_data *other_led_data; > + > + led_data->priv = priv; > + > + ret = is31fl32xx_parse_child_dt(dev, child, led_data); > + if (ret) > + goto err; > + > + /* Detect if channel is already in use by another child */ > + other_led_data = is31fl32xx_find_led_data(priv, > + led_data->channel); > + if (other_led_data) { > + dev_err(dev, > + "%s and %s both attempting to use channel %d\n", > + led_data->cdev.name, > + other_led_data->cdev.name, > + led_data->channel); > + goto err; > + } > + > + ret = devm_led_classdev_register(dev, &led_data->cdev); > + if (ret) { > + dev_err(dev, "failed to register PWM led for %s: %d\n", > + led_data->cdev.name, ret); > + goto err; > + } > + > + priv->num_leds++; > + } > + > + return 0; > + > +err: > + of_node_put(child); > + return ret; > +} > + > +static const struct of_device_id of_is31fl31xx_match[] = { > + { .compatible = "issi,is31fl3236", .data = &is31fl3236_cdef, }, > + { .compatible = "issi,is31fl3235", .data = &is31fl3235_cdef, }, > + { .compatible = "issi,is31fl3218", .data = &is31fl3218_cdef, }, > + { .compatible = "issi,is31fl3216", .data = &is31fl3216_cdef, }, > + {}, > +}; > + > +MODULE_DEVICE_TABLE(of, of_is31fl31xx_match); > + > +static int is31fl32xx_probe(struct i2c_client *client, > + const struct i2c_device_id *id) > +{ > + const struct is31fl32xx_chipdef *cdef; > + const struct of_device_id *of_dev_id; > + struct device *dev = &client->dev; > + struct is31fl32xx_priv *priv; > + int count; > + int ret = 0; > + > + of_dev_id = of_match_device(of_is31fl31xx_match, dev); > + if (!of_dev_id) > + return -EINVAL; > + > + cdef = of_dev_id->data; > + > + count = of_get_child_count(dev->of_node); > + if (!count) > + return -EINVAL; > + > + priv = devm_kzalloc(dev, sizeof_is31fl32xx_priv(count), > + GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + > + priv->client = client; > + priv->cdef = cdef; > + i2c_set_clientdata(client, priv); > + > + ret = is31fl32xx_init_regs(priv); > + if (ret) > + return ret; > + > + ret = is31fl32xx_parse_dt(dev, priv); > + if (ret) > + return ret; > + > + return 0; > +} > + > +static int is31fl32xx_remove(struct i2c_client *client) > +{ > + struct is31fl32xx_priv *priv = i2c_get_clientdata(client); > + > + return is31fl32xx_reset_regs(priv); > +} > + > +/* > + * i2c-core requires that id_table be non-NULL, even though > + * it is not used for DeviceTree based instantiation. > + */ > +static const struct i2c_device_id is31fl31xx_id[] = { > + {}, > +}; > + > +MODULE_DEVICE_TABLE(i2c, is31fl31xx_id); > + > +static struct i2c_driver is31fl32xx_driver = { > + .driver = { > + .name = "is31fl32xx", > + .of_match_table = of_is31fl31xx_match, > + }, > + .probe = is31fl32xx_probe, > + .remove = is31fl32xx_remove, Sorry, what was the reason to skip shutdown? Thanks Stefan > + .id_table = is31fl31xx_id, > +}; > + > +module_i2c_driver(is31fl32xx_driver); > + > +MODULE_AUTHOR("David Rivshin <drivshin@xxxxxxxxxxx>"); > +MODULE_DESCRIPTION("ISSI IS31FL32xx LED driver"); > +MODULE_LICENSE("GPL v2"); > -- > 2.5.0 > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
