/* * Copyright (c) 2022 Henrik Brix Andersen * Copyright (c) 2022 Martin Jäger * * SPDX-License-Identifier: Apache-2.0 */ #define DT_DRV_COMPAT espressif_esp32_twai #include "can_sja1000.h" #include #include #include #include #include #include LOG_MODULE_REGISTER(can_esp32_twai, CONFIG_CAN_LOG_LEVEL); /* * Newer ESP32-series MCUs like ESP32-C3 and ESP32-S2 have some slightly different registers * compared to the original ESP32, which is fully compatible with the SJA1000 controller. * * The names with TWAI_ prefixes from Espressif reference manuals are used for these incompatible * registers. */ #ifndef CONFIG_SOC_ESP32 /* TWAI_BUS_TIMING_0_REG is incompatible with CAN_SJA1000_BTR0 */ #define TWAI_BUS_TIMING_0_REG (6U) #define TWAI_BAUD_PRESC_MASK GENMASK(12, 0) #define TWAI_SYNC_JUMP_WIDTH_MASK GENMASK(15, 14) #define TWAI_BAUD_PRESC_PREP(brp) FIELD_PREP(TWAI_BAUD_PRESC_MASK, brp) #define TWAI_SYNC_JUMP_WIDTH_PREP(sjw) FIELD_PREP(TWAI_SYNC_JUMP_WIDTH_MASK, sjw) /* * TWAI_BUS_TIMING_1_REG is compatible with CAN_SJA1000_BTR1, but needed here for the custom * set_timing() function. */ #define TWAI_BUS_TIMING_1_REG (7U) #define TWAI_TIME_SEG1_MASK GENMASK(3, 0) #define TWAI_TIME_SEG2_MASK GENMASK(6, 4) #define TWAI_TIME_SAMP BIT(7) #define TWAI_TIME_SEG1_PREP(seg1) FIELD_PREP(TWAI_TIME_SEG1_MASK, seg1) #define TWAI_TIME_SEG2_PREP(seg2) FIELD_PREP(TWAI_TIME_SEG2_MASK, seg2) /* TWAI_CLOCK_DIVIDER_REG is incompatible with CAN_SJA1000_CDR */ #define TWAI_CLOCK_DIVIDER_REG (31U) #define TWAI_CD_MASK GENMASK(7, 0) #define TWAI_CLOCK_OFF BIT(8) /* * Further incompatible registers currently not used by the driver: * - TWAI_STATUS_REG has new bit 8: TWAI_MISS_ST * - TWAI_INT_RAW_REG has new bit 8: TWAI_BUS_STATE_INT_ST * - TWAI_INT_ENA_REG has new bit 8: TWAI_BUS_STATE_INT_ENA */ #else /* Redefinitions of the SJA1000 CDR bits to simplify driver config */ #define TWAI_CD_MASK GENMASK(2, 0) #define TWAI_CLOCK_OFF BIT(3) #endif /* !CONFIG_SOC_ESP32 */ struct can_esp32_twai_config { mm_reg_t base; const struct pinctrl_dev_config *pcfg; const struct device *clock_dev; const clock_control_subsys_t clock_subsys; int irq_source; #ifndef CONFIG_SOC_ESP32 /* 32-bit variant of output clock divider register required for non-ESP32 MCUs */ uint32_t cdr32; #endif /* !CONFIG_SOC_ESP32 */ }; static uint8_t can_esp32_twai_read_reg(const struct device *dev, uint8_t reg) { const struct can_sja1000_config *sja1000_config = dev->config; const struct can_esp32_twai_config *twai_config = sja1000_config->custom; mm_reg_t addr = twai_config->base + reg * sizeof(uint32_t); return sys_read32(addr) & 0xFF; } static void can_esp32_twai_write_reg(const struct device *dev, uint8_t reg, uint8_t val) { const struct can_sja1000_config *sja1000_config = dev->config; const struct can_esp32_twai_config *twai_config = sja1000_config->custom; mm_reg_t addr = twai_config->base + reg * sizeof(uint32_t); sys_write32(val & 0xFF, addr); } #ifndef CONFIG_SOC_ESP32 /* * Required for newer ESP32-series MCUs which violate the original SJA1000 8-bit register size. */ static void can_esp32_twai_write_reg32(const struct device *dev, uint8_t reg, uint32_t val) { const struct can_sja1000_config *sja1000_config = dev->config; const struct can_esp32_twai_config *twai_config = sja1000_config->custom; mm_reg_t addr = twai_config->base + reg * sizeof(uint32_t); sys_write32(val, addr); } /* * Custom implementation instead of can_sja1000_set_timing required because TWAI_BUS_TIMING_0_REG * is incompatible with CAN_SJA1000_BTR0. */ static int can_esp32_twai_set_timing(const struct device *dev, const struct can_timing *timing) { struct can_sja1000_data *data = dev->data; uint8_t btr0; uint8_t btr1; uint8_t sjw; __ASSERT_NO_MSG(timing->sjw == CAN_SJW_NO_CHANGE || (timing->sjw >= 0x1 && timing->sjw <= 0x4)); __ASSERT_NO_MSG(timing->prop_seg == 0); __ASSERT_NO_MSG(timing->phase_seg1 >= 0x1 && timing->phase_seg1 <= 0x10); __ASSERT_NO_MSG(timing->phase_seg2 >= 0x1 && timing->phase_seg2 <= 0x8); __ASSERT_NO_MSG(timing->prescaler >= 0x1 && timing->prescaler <= 0x2000); if (data->started) { return -EBUSY; } k_mutex_lock(&data->mod_lock, K_FOREVER); if (timing->sjw == CAN_SJW_NO_CHANGE) { sjw = data->sjw; } else { sjw = timing->sjw; data->sjw = timing->sjw; } btr0 = TWAI_BAUD_PRESC_PREP(timing->prescaler - 1) | TWAI_SYNC_JUMP_WIDTH_PREP(sjw - 1); btr1 = TWAI_TIME_SEG1_PREP(timing->phase_seg1 - 1) | TWAI_TIME_SEG2_PREP(timing->phase_seg2 - 1); if ((data->mode & CAN_MODE_3_SAMPLES) != 0) { btr1 |= TWAI_TIME_SAMP; } can_esp32_twai_write_reg32(dev, TWAI_BUS_TIMING_0_REG, btr0); can_esp32_twai_write_reg32(dev, TWAI_BUS_TIMING_1_REG, btr1); k_mutex_unlock(&data->mod_lock); return 0; } #endif /* !CONFIG_SOC_ESP32 */ static int can_esp32_twai_get_core_clock(const struct device *dev, uint32_t *rate) { ARG_UNUSED(dev); /* The internal clock operates at half of the oscillator frequency */ *rate = APB_CLK_FREQ / 2; return 0; } static void IRAM_ATTR can_esp32_twai_isr(void *arg) { const struct device *dev = (const struct device *)arg; can_sja1000_isr(dev); } static int can_esp32_twai_init(const struct device *dev) { const struct can_sja1000_config *sja1000_config = dev->config; const struct can_esp32_twai_config *twai_config = sja1000_config->custom; int err; if (!device_is_ready(twai_config->clock_dev)) { LOG_ERR("clock control device not ready"); return -ENODEV; } err = pinctrl_apply_state(twai_config->pcfg, PINCTRL_STATE_DEFAULT); if (err != 0) { LOG_ERR("failed to configure TWAI pins (err %d)", err); return err; } err = clock_control_on(twai_config->clock_dev, twai_config->clock_subsys); if (err != 0) { LOG_ERR("failed to enable CAN clock (err %d)", err); return err; } err = can_sja1000_init(dev); if (err != 0) { LOG_ERR("failed to initialize controller (err %d)", err); return err; } #ifndef CONFIG_SOC_ESP32 /* * TWAI_CLOCK_DIVIDER_REG is incompatible with CAN_SJA1000_CDR for non-ESP32 MCUs * - TWAI_CD has length of 8 bits instead of 3 bits * - TWAI_CLOCK_OFF at BIT(8) instead of BIT(3) * - TWAI_EXT_MODE bit missing (always "extended" = PeliCAN mode) * * Overwrite with 32-bit register variant configured via devicetree. */ can_esp32_twai_write_reg32(dev, TWAI_CLOCK_DIVIDER_REG, twai_config->cdr32); #endif /* !CONFIG_SOC_ESP32 */ esp_intr_alloc(twai_config->irq_source, 0, can_esp32_twai_isr, (void *)dev, NULL); return 0; } const struct can_driver_api can_esp32_twai_driver_api = { .get_capabilities = can_sja1000_get_capabilities, .start = can_sja1000_start, .stop = can_sja1000_stop, .set_mode = can_sja1000_set_mode, #ifdef CONFIG_SOC_ESP32 .set_timing = can_sja1000_set_timing, #else .set_timing = can_esp32_twai_set_timing, #endif /* CONFIG_SOC_ESP32 */ .send = can_sja1000_send, .add_rx_filter = can_sja1000_add_rx_filter, .remove_rx_filter = can_sja1000_remove_rx_filter, .get_state = can_sja1000_get_state, .set_state_change_callback = can_sja1000_set_state_change_callback, .get_core_clock = can_esp32_twai_get_core_clock, .get_max_filters = can_sja1000_get_max_filters, .get_max_bitrate = can_sja1000_get_max_bitrate, #ifndef CONFIG_CAN_AUTO_BUS_OFF_RECOVERY .recover = can_sja1000_recover, #endif /* !CONFIG_CAN_AUTO_BUS_OFF_RECOVERY */ .timing_min = CAN_SJA1000_TIMING_MIN_INITIALIZER, #ifdef CONFIG_SOC_ESP32 .timing_max = CAN_SJA1000_TIMING_MAX_INITIALIZER, #else /* larger prescaler allowed for newer ESP32-series MCUs */ .timing_max = { .sjw = 0x4, .prop_seg = 0x0, .phase_seg1 = 0x10, .phase_seg2 = 0x8, .prescaler = 0x2000, } #endif /* CONFIG_SOC_ESP32 */ }; #ifdef CONFIG_SOC_ESP32 #define TWAI_CLKOUT_DIVIDER_MAX (14) #define TWAI_CDR32_INIT(inst) #else #define TWAI_CLKOUT_DIVIDER_MAX (490) #define TWAI_CDR32_INIT(inst) .cdr32 = CAN_ESP32_TWAI_DT_CDR_INST_GET(inst) #endif /* CONFIG_SOC_ESP32 */ #define CAN_ESP32_TWAI_ASSERT_CLKOUT_DIVIDER(inst) \ BUILD_ASSERT(COND_CODE_0(DT_INST_NODE_HAS_PROP(inst, clkout_divider), (1), \ (DT_INST_PROP(inst, clkout_divider) == 1 || \ (DT_INST_PROP(inst, clkout_divider) % 2 == 0 && \ DT_INST_PROP(inst, clkout_divider) / 2 <= TWAI_CLKOUT_DIVIDER_MAX))), \ "TWAI clkout-divider from dts invalid") #define CAN_ESP32_TWAI_DT_CDR_INST_GET(inst) \ COND_CODE_1(DT_INST_NODE_HAS_PROP(inst, clkout_divider), \ COND_CODE_1(DT_INST_PROP(inst, clkout_divider) == 1, (TWAI_CD_MASK), \ ((DT_INST_PROP(inst, clkout_divider)) / 2 - 1)), \ (TWAI_CLOCK_OFF)) #define CAN_ESP32_TWAI_INIT(inst) \ PINCTRL_DT_INST_DEFINE(inst); \ \ static const struct can_esp32_twai_config can_esp32_twai_config_##inst = { \ .base = DT_INST_REG_ADDR(inst), \ .clock_dev = DEVICE_DT_GET(DT_INST_CLOCKS_CTLR(inst)), \ .clock_subsys = (clock_control_subsys_t)DT_INST_CLOCKS_CELL(inst, offset), \ .pcfg = PINCTRL_DT_INST_DEV_CONFIG_GET(inst), \ .irq_source = DT_INST_IRQN(inst), \ TWAI_CDR32_INIT(inst) \ }; \ CAN_ESP32_TWAI_ASSERT_CLKOUT_DIVIDER(inst); \ static const struct can_sja1000_config can_sja1000_config_##inst = \ CAN_SJA1000_DT_CONFIG_INST_GET(inst, &can_esp32_twai_config_##inst, \ can_esp32_twai_read_reg, can_esp32_twai_write_reg, \ CAN_SJA1000_OCR_OCMODE_BIPHASE, \ COND_CODE_0(IS_ENABLED(CONFIG_SOC_ESP32), (0), \ (CAN_ESP32_TWAI_DT_CDR_INST_GET(inst)))); \ \ static struct can_sja1000_data can_sja1000_data_##inst = \ CAN_SJA1000_DATA_INITIALIZER(NULL); \ \ DEVICE_DT_INST_DEFINE(inst, can_esp32_twai_init, NULL, &can_sja1000_data_##inst, \ &can_sja1000_config_##inst, POST_KERNEL, \ CONFIG_CAN_INIT_PRIORITY, &can_esp32_twai_driver_api); DT_INST_FOREACH_STATUS_OKAY(CAN_ESP32_TWAI_INIT)