/* * 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 */ #include #include #include #include #include #include #include /* 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); } 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]; 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, .id_table = is31fl31xx_id, }; module_i2c_driver(is31fl32xx_driver); MODULE_AUTHOR("David Rivshin "); MODULE_DESCRIPTION("ISSI IS31FL32xx LED driver"); MODULE_LICENSE("GPL v2");