| /* |
| * Copyright (c) 2019 Intel Corporation |
| * Copyright (c) 2022 Microchip Technololgy Inc. |
| * |
| * SPDX-License-Identifier: Apache-2.0 |
| */ |
| |
| #define DT_DRV_COMPAT microchip_xec_pwm |
| |
| #include <errno.h> |
| #include <stdlib.h> |
| #include <stdint.h> |
| |
| #include <zephyr/device.h> |
| #include <zephyr/drivers/pwm.h> |
| #ifdef CONFIG_SOC_SERIES_MEC172X |
| #include <zephyr/drivers/clock_control/mchp_xec_clock_control.h> |
| #include <zephyr/drivers/interrupt_controller/intc_mchp_xec_ecia.h> |
| #endif |
| #include <zephyr/drivers/pinctrl.h> |
| #include <zephyr/logging/log.h> |
| |
| #include <soc.h> |
| |
| LOG_MODULE_REGISTER(pwm_mchp_xec, CONFIG_PWM_LOG_LEVEL); |
| |
| /* Minimal on/off are 1 & 1 both are incremented, so 4. |
| * 0 cannot be set (used for full low/high output) so a |
| * combination of on_off of 2 is not possible. |
| */ |
| #define XEC_PWM_LOWEST_ON_OFF 4U |
| /* Maximal on/off are UINT16_T, both are incremented. |
| * Multiplied by the highest divider: 16 |
| */ |
| #define XEC_PWM_HIGHEST_ON_OFF (2U * (UINT16_MAX + 1U) * 16U) |
| |
| #define XEC_PWM_MIN_HIGH_CLK_FREQ \ |
| (MCHP_PWM_INPUT_FREQ_HI / XEC_PWM_HIGHEST_ON_OFF) |
| #define XEC_PWM_MAX_LOW_CLK_FREQ \ |
| (MCHP_PWM_INPUT_FREQ_LO / XEC_PWM_LOWEST_ON_OFF) |
| /* Precision factor for frequency calculation |
| * To mitigate frequency comparision up to the first digit after 0. |
| */ |
| #define XEC_PWM_FREQ_PF 10U |
| /* Precision factor for DC calculation |
| * To avoid losing some digits after 0. |
| */ |
| #define XEC_PWM_DC_PF 100000U |
| /* Lowest reachable frequency */ |
| #define XEC_PWM_FREQ_LIMIT 1 /* 0.1hz * XEC_PWM_FREQ_PF */ |
| |
| struct pwm_xec_config { |
| struct pwm_regs * const regs; |
| uint8_t pcr_idx; |
| uint8_t pcr_pos; |
| const struct pinctrl_dev_config *pcfg; |
| }; |
| |
| struct xec_params { |
| uint32_t on; |
| uint32_t off; |
| uint8_t div; |
| }; |
| |
| #define NUM_DIV_ELEMS 16 |
| |
| static const uint32_t max_freq_high_on_div[NUM_DIV_ELEMS] = { |
| 48000000, |
| 24000000, |
| 16000000, |
| 12000000, |
| 9600000, |
| 8000000, |
| 6857142, |
| 6000000, |
| 5333333, |
| 4800000, |
| 4363636, |
| 4000000, |
| 3692307, |
| 3428571, |
| 3200000, |
| 3000000, |
| }; |
| |
| static const uint32_t max_freq_low_on_div[NUM_DIV_ELEMS] = { |
| 100000, |
| 50000, |
| 33333, |
| 25000, |
| 20000, |
| 16666, |
| 14285, |
| 12500, |
| 11111, |
| 10000, |
| 9090, |
| 8333, |
| 7692, |
| 7142, |
| 6666, |
| 6250, |
| }; |
| |
| static uint32_t xec_compute_frequency(uint32_t clk, uint32_t on, uint32_t off) |
| { |
| return ((clk * XEC_PWM_FREQ_PF)/((on + 1) + (off + 1))); |
| } |
| |
| static uint16_t xec_select_div(uint32_t freq, const uint32_t max_freq[16]) |
| { |
| uint8_t i; |
| |
| if (freq >= max_freq[3]) { |
| return 0; |
| } |
| |
| freq *= XEC_PWM_LOWEST_ON_OFF; |
| |
| for (i = 0; i < 15; i++) { |
| if (freq >= max_freq[i]) { |
| break; |
| } |
| } |
| |
| return i; |
| } |
| |
| static void xec_compute_on_off(uint32_t freq, uint32_t dc, uint32_t clk, |
| uint32_t *on, uint32_t *off) |
| { |
| uint64_t on_off; |
| |
| on_off = (clk * 10) / freq; |
| |
| *on = ((on_off * dc) / XEC_PWM_DC_PF) - 1; |
| *off = on_off - *on - 2; |
| } |
| |
| static uint32_t xec_compute_dc(uint32_t on, uint32_t off) |
| { |
| int dc = (on + 1) + (off + 1); |
| |
| /* Make calculation in uint64_t since XEC_PWM_DC_PF is large */ |
| dc = (((uint64_t)(on + 1) * XEC_PWM_DC_PF) / dc); |
| |
| return (uint32_t)dc; |
| } |
| |
| static uint16_t xec_compare_div_on_off(uint32_t target_freq, uint32_t dc, |
| const uint32_t max_freq[16], |
| uint8_t div_a, uint8_t div_b, |
| uint32_t *on_a, uint32_t *off_a) |
| { |
| uint32_t freq_a, freq_b, on_b, off_b; |
| |
| xec_compute_on_off(target_freq, dc, max_freq[div_a], |
| on_a, off_a); |
| |
| freq_a = xec_compute_frequency(max_freq[div_a], *on_a, *off_a); |
| |
| xec_compute_on_off(target_freq, dc, max_freq[div_b], |
| &on_b, &off_b); |
| |
| freq_b = xec_compute_frequency(max_freq[div_b], on_b, off_b); |
| |
| if ((target_freq - freq_a) < (target_freq - freq_b)) { |
| if ((*on_a <= UINT16_MAX) && (*off_a <= UINT16_MAX)) { |
| return div_a; |
| } |
| } |
| |
| if ((on_b <= UINT16_MAX) && (off_b <= UINT16_MAX)) { |
| *on_a = on_b; |
| *off_a = off_b; |
| |
| return div_b; |
| } |
| |
| return div_a; |
| } |
| |
| static uint8_t xec_select_best_div_on_off(uint32_t target_freq, uint32_t dc, |
| const uint32_t max_freq[16], |
| uint32_t *on, uint32_t *off) |
| { |
| int div_comp; |
| uint8_t div; |
| |
| div = xec_select_div(target_freq, max_freq); |
| |
| for (div_comp = (int)div - 1; div_comp >= 0; div_comp--) { |
| div = xec_compare_div_on_off(target_freq, dc, max_freq, |
| div, div_comp, on, off); |
| } |
| |
| return div; |
| } |
| |
| static struct xec_params *xec_compare_params(uint32_t target_freq, |
| struct xec_params *hc_params, |
| struct xec_params *lc_params) |
| { |
| struct xec_params *params; |
| uint32_t freq_h = 0; |
| uint32_t freq_l = 0; |
| |
| if (hc_params->div < NUM_DIV_ELEMS) { |
| freq_h = xec_compute_frequency( |
| max_freq_high_on_div[hc_params->div], |
| hc_params->on, |
| hc_params->off); |
| } |
| |
| if (lc_params->div < NUM_DIV_ELEMS) { |
| freq_l = xec_compute_frequency( |
| max_freq_low_on_div[lc_params->div], |
| lc_params->on, |
| lc_params->off); |
| } |
| |
| if (abs((int)target_freq - (int)freq_h) < |
| abs((int)target_freq - (int)freq_l)) { |
| params = hc_params; |
| } else { |
| params = lc_params; |
| } |
| |
| LOG_DBG("\tFrequency (x%u): %u", XEC_PWM_FREQ_PF, freq_h); |
| LOG_DBG("\tOn %s clock, ON %u OFF %u DIV %u", |
| params == hc_params ? "High" : "Low", |
| params->on, params->off, params->div); |
| |
| return params; |
| } |
| |
| static void xec_compute_and_set_parameters(const struct device *dev, |
| uint32_t target_freq, |
| uint32_t on, uint32_t off) |
| { |
| const struct pwm_xec_config * const cfg = dev->config; |
| struct pwm_regs * const regs = cfg->regs; |
| bool compute_high, compute_low; |
| struct xec_params hc_params; |
| struct xec_params lc_params; |
| struct xec_params *params; |
| uint32_t dc, cfgval; |
| |
| dc = xec_compute_dc(on, off); |
| |
| compute_high = (target_freq >= XEC_PWM_MIN_HIGH_CLK_FREQ); |
| compute_low = (target_freq <= XEC_PWM_MAX_LOW_CLK_FREQ); |
| |
| LOG_DBG("Target freq (x%u): %u and DC %u per-cent", |
| XEC_PWM_FREQ_PF, target_freq, (dc / 1000)); |
| |
| if (compute_high) { |
| if (!compute_low |
| && (on <= UINT16_MAX) |
| && (off <= UINT16_MAX)) { |
| hc_params.on = on; |
| hc_params.off = off; |
| hc_params.div = 0; |
| lc_params.div = UINT8_MAX; |
| |
| goto done; |
| } |
| |
| hc_params.div = xec_select_best_div_on_off( |
| target_freq, dc, |
| max_freq_high_on_div, |
| &hc_params.on, |
| &hc_params.off); |
| LOG_DBG("Best div high: %u (on/off: %u/%u)", |
| hc_params.div, hc_params.on, hc_params.off); |
| } else { |
| hc_params.div = UINT8_MAX; |
| } |
| |
| if (compute_low) { |
| lc_params.div = xec_select_best_div_on_off( |
| target_freq, dc, |
| max_freq_low_on_div, |
| &lc_params.on, |
| &lc_params.off); |
| LOG_DBG("Best div low: %u (on/off: %u/%u)", |
| lc_params.div, lc_params.on, lc_params.off); |
| } else { |
| lc_params.div = UINT8_MAX; |
| } |
| done: |
| regs->CONFIG &= ~MCHP_PWM_CFG_ENABLE; |
| |
| cfgval = regs->CONFIG; |
| |
| params = xec_compare_params(target_freq, &hc_params, &lc_params); |
| if (params == &hc_params) { |
| cfgval &= ~MCHP_PWM_CFG_CLK_SEL_100K; |
| } else { |
| cfgval |= MCHP_PWM_CFG_CLK_SEL_100K; |
| } |
| |
| regs->COUNT_ON = params->on; |
| regs->COUNT_OFF = params->off; |
| cfgval &= ~MCHP_PWM_CFG_CLK_PRE_DIV(0xF); |
| cfgval |= MCHP_PWM_CFG_CLK_PRE_DIV(params->div); |
| cfgval |= MCHP_PWM_CFG_ENABLE; |
| |
| regs->CONFIG = cfgval; |
| } |
| |
| static int pwm_xec_set_cycles(const struct device *dev, uint32_t channel, |
| uint32_t period_cycles, uint32_t pulse_cycles, |
| pwm_flags_t flags) |
| { |
| const struct pwm_xec_config * const cfg = dev->config; |
| struct pwm_regs * const regs = cfg->regs; |
| uint32_t target_freq; |
| uint32_t on, off; |
| |
| if (channel > 0) { |
| return -EIO; |
| } |
| |
| if (flags & PWM_POLARITY_INVERTED) |
| regs->CONFIG |= MCHP_PWM_CFG_ON_POL_LO; |
| |
| on = pulse_cycles; |
| off = period_cycles - pulse_cycles; |
| |
| target_freq = xec_compute_frequency(MCHP_PWM_INPUT_FREQ_HI, on, off); |
| if (target_freq < XEC_PWM_FREQ_LIMIT) { |
| LOG_DBG("Target frequency below limit"); |
| return -EINVAL; |
| } |
| |
| if ((pulse_cycles == 0U) && (period_cycles == 0U)) { |
| regs->CONFIG &= ~MCHP_PWM_CFG_ENABLE; |
| } else if ((pulse_cycles == 0U) && (period_cycles > 0U)) { |
| regs->COUNT_ON = 0; |
| regs->COUNT_OFF = 1; |
| } else if ((pulse_cycles > 0U) && (period_cycles == 0U)) { |
| regs->COUNT_ON = 1; |
| regs->COUNT_OFF = 0; |
| } else { |
| xec_compute_and_set_parameters(dev, target_freq, on, off); |
| } |
| |
| return 0; |
| } |
| |
| static int pwm_xec_get_cycles_per_sec(const struct device *dev, |
| uint32_t channel, uint64_t *cycles) |
| { |
| ARG_UNUSED(dev); |
| |
| if (channel > 0) { |
| return -EIO; |
| } |
| |
| if (cycles) { |
| /* User does not have to know about lowest clock, |
| * the driver will select the most relevant one. |
| */ |
| *cycles = MCHP_PWM_INPUT_FREQ_HI; |
| } |
| |
| return 0; |
| } |
| |
| static const struct pwm_driver_api pwm_xec_driver_api = { |
| .set_cycles = pwm_xec_set_cycles, |
| .get_cycles_per_sec = pwm_xec_get_cycles_per_sec, |
| }; |
| |
| static int pwm_xec_init(const struct device *dev) |
| { |
| const struct pwm_xec_config * const cfg = dev->config; |
| int ret = pinctrl_apply_state(cfg->pcfg, PINCTRL_STATE_DEFAULT); |
| |
| if (ret != 0) { |
| LOG_ERR("XEC PWM pinctrl init failed (%d)", ret); |
| return ret; |
| } |
| |
| return 0; |
| } |
| |
| #define XEC_PWM_CONFIG(inst) \ |
| static struct pwm_xec_config pwm_xec_config_##inst = { \ |
| .regs = (struct pwm_regs * const)DT_INST_REG_ADDR(inst), \ |
| .pcr_idx = (uint8_t)DT_INST_PROP_BY_IDX(inst, pcrs, 0), \ |
| .pcr_pos = (uint8_t)DT_INST_PROP_BY_IDX(inst, pcrs, 1), \ |
| .pcfg = PINCTRL_DT_INST_DEV_CONFIG_GET(inst), \ |
| }; |
| |
| #define XEC_PWM_DEVICE_INIT(index) \ |
| \ |
| PINCTRL_DT_INST_DEFINE(index); \ |
| \ |
| XEC_PWM_CONFIG(index); \ |
| \ |
| DEVICE_DT_INST_DEFINE(index, &pwm_xec_init, \ |
| NULL, \ |
| NULL, \ |
| &pwm_xec_config_##index, POST_KERNEL, \ |
| CONFIG_PWM_INIT_PRIORITY, \ |
| &pwm_xec_driver_api); |
| |
| DT_INST_FOREACH_STATUS_OKAY(XEC_PWM_DEVICE_INIT) |