// SPDX-License-Identifier: GPL-2.0-or-later /* * Driver for Sercomm MSP430G2513 LEDs. * * Copyright 2023 Álvaro Fernández Rojas */ #include #include #include #include #include #include "leds.h" /* * MSP430G2513 SPI protocol description: * +----+----+----+----+----+----+ * | b1 | b2 | b3 | b4 | b5 | b6 | * +----+----+----+----+----+----+ * 6 bytes TX & RX per transaction. * * LEDs: * MSP430G2513 can control up to 9 LEDs. * b1: LED ID [1,9] * b2: LED function * b3-b6: LED function parameters * * LED functions: * [0] Off * [1] On * [2] Flash * - b4: delay (x 6ms) * - b5: repeat (0 = infinite) * [3] Pulse * - b3: delay (x 6ms) * - b4: blink while pulsing? (unknown) * - b5: repeat (0 = infinite) * [4] Pulse On * - b3: delay (x 6ms) * - b4: blink while pulsing? (unknown) * - b5: repeat (0 = infinite) * [5] Pulse Off * - b3: delay (x 6ms) * - b4: blink while pulsing? (unknown) * - b5: repeat (0 = infinite) * [6] Level * - b3: brightness [0,4] * * MCU Commands (b1 = 0x55): * [0x0a] FW upgrade data * - b3: Data size (usually 0x40), which is appended to TX & RX. * [0x31] Get MCU version? (unknown) * [0x68] Get MCU work mode * [0xa5] Start FW upgrade * [0xf0] End FW upgrade */ #define MSP430_CMD_BYTES 6 #define MSP430_CMD_MCU 0x55 #define MSP430_MCU_WM 0x68 #define MSP430_LED_MIN_ID 1 #define MSP430_LED_MAX_ID 9 #define MSP430_LED_OFF 0 #define MSP430_LED_ON 1 #define MSP430_LED_FLASH 2 #define MSP430_LED_PULSE 3 #define MSP430_LED_PULSE_ON 4 #define MSP430_LED_PULSE_OFF 5 #define MSP430_LED_LEVEL 6 #define MSP430_LED_BLINK_DEF 500 #define MSP430_LED_BLINK_MASK 0xff #define MSP430_LED_BLINK_MS 6 #define MSP430_LED_BLINK_MAX (MSP430_LED_BLINK_MS * \ MSP430_LED_BLINK_MASK) #define MSP430_LED_BRIGHTNESS_MAX 5 #define MSP430_LED_REPEAT_MAX 0xff /** * struct msp430_led - state container for Sercomm MSP430 based LEDs * @cdev: LED class device for this LED * @spi: spi resource * @id: LED ID */ struct msp430_led { struct led_classdev cdev; struct spi_device *spi; u8 id; }; static inline int msp430_cmd(struct spi_device *spi, u8 tx[MSP430_CMD_BYTES], u8 rx[MSP430_CMD_BYTES]) { struct device *dev = &spi->dev; int rc; memset(rx, 0, MSP430_CMD_BYTES); rc = spi_write_then_read(spi, tx, MSP430_CMD_BYTES, rx, MSP430_CMD_BYTES); if (rc) dev_err(dev, "spi error\n"); dev_dbg(dev, "msp430_cmd: [%02x %02x %02x %02x %02x %02x]" " -> [%02x %02x %02x %02x %02x %02x]", tx[0], tx[1], tx[2], tx[3], tx[4], tx[5], rx[0], rx[1], rx[2], rx[3], rx[4], rx[5]); return rc; } static unsigned long msp430_blink_delay(unsigned long delay) { unsigned long msp430_delay; msp430_delay = delay + MSP430_LED_BLINK_MS / 2; msp430_delay = msp430_delay / MSP430_LED_BLINK_MS; if (msp430_delay == 0) msp430_delay = 1; return msp430_delay; } static int msp430_blink_set(struct led_classdev *led_cdev, unsigned long *delay_on, unsigned long *delay_off) { struct msp430_led *led = container_of(led_cdev, struct msp430_led, cdev); u8 tx[MSP430_CMD_BYTES] = {led->id, MSP430_LED_FLASH, 0, 0, 0, 0}; u8 rx[MSP430_CMD_BYTES]; unsigned long delay; if (!*delay_on) *delay_on = MSP430_LED_BLINK_DEF; if (!*delay_off) *delay_off = MSP430_LED_BLINK_DEF; delay = msp430_blink_delay(*delay_on); if (delay != msp430_blink_delay(*delay_off)) { dev_dbg(led_cdev->dev, "fallback to soft blinking (delay_on != delay_off)\n"); return -EINVAL; } if (delay > MSP430_LED_BLINK_MASK) { dev_dbg(led_cdev->dev, "fallback to soft blinking (delay > %ums)\n", MSP430_LED_BLINK_MAX); return -EINVAL; } tx[3] = delay; return msp430_cmd(led->spi, tx, rx); } static int msp430_brightness_set(struct led_classdev *led_cdev, enum led_brightness brightness) { struct msp430_led *led = container_of(led_cdev, struct msp430_led, cdev); u8 tx[MSP430_CMD_BYTES] = {led->id, 0, 0, 0, 0, 0}; u8 rx[MSP430_CMD_BYTES]; u8 val = (u8) brightness; switch (val) { case LED_OFF: tx[1] = MSP430_LED_OFF; break; case MSP430_LED_BRIGHTNESS_MAX: tx[1] = MSP430_LED_ON; break; default: tx[1] = MSP430_LED_LEVEL; tx[2] = val - 1; break; } return msp430_cmd(led->spi, tx, rx); } static int msp430_pattern_clear(struct led_classdev *ldev) { msp430_brightness_set(ldev, LED_OFF); return 0; } static int msp430_pattern_set(struct led_classdev *led_cdev, struct led_pattern *pattern, u32 len, int repeat) { struct msp430_led *led = container_of(led_cdev, struct msp430_led, cdev); u8 tx[MSP430_CMD_BYTES] = {led->id, 0, 0, 0, 0, 0}; u8 rx[MSP430_CMD_BYTES]; unsigned long delay0; unsigned long delay1; int rc; if (len != 2 || repeat > MSP430_LED_REPEAT_MAX || pattern[0].delta_t > MSP430_LED_BLINK_MAX || pattern[1].delta_t > MSP430_LED_BLINK_MAX) return -EINVAL; delay0 = msp430_blink_delay(pattern[0].delta_t); delay1 = msp430_blink_delay(pattern[1].delta_t); /* Infinite pattern */ if (repeat < 0) repeat = 0; /* Pulse: */ if (delay0 == delay1 && pattern[0].brightness == LED_OFF && pattern[1].brightness == MSP430_LED_BRIGHTNESS_MAX) { tx[1] = MSP430_LED_PULSE; tx[2] = delay0; tx[4] = (u8) repeat; } /* Pulse On: <0ms> */ if (pattern[0].delta_t != 0 && pattern[1].delta_t == 0 && pattern[0].brightness == LED_OFF && pattern[1].brightness == MSP430_LED_BRIGHTNESS_MAX) { tx[1] = MSP430_LED_PULSE_ON; tx[2] = delay0; tx[4] = (u8) repeat; } /* Pulse Off: <0ms> */ if (pattern[0].delta_t != 0 && pattern[1].delta_t == 0 && pattern[0].brightness == MSP430_LED_BRIGHTNESS_MAX && pattern[1].brightness == LED_OFF) { tx[1] = MSP430_LED_PULSE_OFF; tx[2] = delay0; tx[4] = (u8) repeat; } if (!tx[1]) return -EINVAL; rc = msp430_cmd(led->spi, tx, rx); if (rc) return rc; return 0; } static int msp430_led(struct spi_device *spi, struct device_node *nc, u8 id) { struct device *dev = &spi->dev; struct led_init_data init_data = {}; struct msp430_led *led; enum led_default_state state; int rc; led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL); if (!led) return -ENOMEM; led->id = id; led->spi = spi; init_data.fwnode = of_fwnode_handle(nc); state = led_init_default_state_get(init_data.fwnode); switch (state) { case LEDS_DEFSTATE_ON: led->cdev.brightness = MSP430_LED_BRIGHTNESS_MAX; break; default: led->cdev.brightness = LED_OFF; break; } msp430_brightness_set(&led->cdev, led->cdev.brightness); led->cdev.blink_set = msp430_blink_set; led->cdev.brightness_set_blocking = msp430_brightness_set; led->cdev.max_brightness = MSP430_LED_BRIGHTNESS_MAX; led->cdev.pattern_clear = msp430_pattern_clear; led->cdev.pattern_set = msp430_pattern_set; rc = devm_led_classdev_register_ext(dev, &led->cdev, &init_data); if (rc < 0) return rc; dev_dbg(dev, "registered LED %s\n", led->cdev.name); return 0; } static inline int msp430_check_workmode(struct spi_device *spi) { struct device *dev = &spi->dev; u8 tx[MSP430_CMD_BYTES] = {MSP430_CMD_MCU, MSP430_MCU_WM, 0, 0, 0, 0}; u8 rx[MSP430_CMD_BYTES]; int rc; rc = msp430_cmd(spi, tx, rx); if (rc) return rc; if ((rx[3] == 0xA5 && rx[4] == 'Z') || (rx[4] == 0xA5 && rx[5] == 'Z') || (rx[4] == '\b' && rx[5] == '\n')) { dev_err(dev, "invalid workmode: " "[%02x %02x %02x %02x %02x %02x]\n", rx[0], rx[1], rx[2], rx[3], rx[4], rx[5]); return -EINVAL; } return 0; } static int msp430_leds_probe(struct spi_device *spi) { struct device *dev = &spi->dev; struct device_node *np = dev_of_node(dev); struct device_node *child; int rc; rc = msp430_check_workmode(spi); if (rc) return rc; for_each_available_child_of_node(np, child) { u32 reg; if (of_property_read_u32(child, "reg", ®)) continue; if (reg < MSP430_LED_MIN_ID || reg > MSP430_LED_MAX_ID) { dev_err(dev, "invalid LED (%u) [%d, %d]\n", reg, MSP430_LED_MIN_ID, MSP430_LED_MAX_ID); continue; } rc = msp430_led(spi, child, reg); if (rc < 0) { of_node_put(child); return rc; } } return 0; } static const struct of_device_id msp430_leds_of_match[] = { { .compatible = "sercomm,msp430-leds", }, { /* sentinel */ }, }; MODULE_DEVICE_TABLE(of, msp430_leds_of_match); static const struct spi_device_id msp430_leds_id_table[] = { { "msp430-leds", 0 }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(spi, msp430_leds_id_table); static struct spi_driver msp430_leds_driver = { .driver = { .name = KBUILD_MODNAME, .of_match_table = msp430_leds_of_match, }, .id_table = msp430_leds_id_table, .probe = msp430_leds_probe, }; module_spi_driver(msp430_leds_driver); MODULE_AUTHOR("Álvaro Fernández Rojas "); MODULE_DESCRIPTION("LED driver for Sercomm MSP430 controllers"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("platform:leds-sercomm-msp430");