/* * Copyright (c) 2016 Intel Corporation. * * SPDX-License-Identifier: Apache-2.0 */ #include #include #include #include #include #include #include #include "qm_pwm.h" #include "clk.h" #define HW_CLOCK_CYCLES_PER_USEC (CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC / \ USEC_PER_SEC) /* pwm uses 32 bits counter to control low and high period */ #define MAX_LOW_PERIOD_IN_HW_CLOCK_CYCLES (((u64_t)1) << 32) #define MAX_HIGH_PERIOD_IN_HW_CLOCK_CYCLES (((u64_t)1) << 32) #define MAX_PERIOD_IN_HW_CLOCK_CYCLES (MAX_LOW_PERIOD_IN_HW_CLOCK_CYCLES + \ MAX_HIGH_PERIOD_IN_HW_CLOCK_CYCLES) /* in micro seconds. */ #define MAX_PERIOD (MAX_PERIOD_IN_HW_CLOCK_CYCLES / HW_CLOCK_CYCLES_PER_USEC) /** * in micro seconds. To be able to get 1% granularity, MIN_PERIOD should * have at least 100 HW clock cycles. */ #define MIN_PERIOD ((100 + (HW_CLOCK_CYCLES_PER_USEC - 1)) / \ HW_CLOCK_CYCLES_PER_USEC) /* in micro seconds */ #define DEFAULT_PERIOD 2000 struct pwm_data { #ifdef CONFIG_PWM_QMSI_API_REENTRANCY struct k_sem sem; #endif #ifdef CONFIG_DEVICE_POWER_MANAGEMENT u32_t device_power_state; #endif u32_t channel_period[CONFIG_PWM_QMSI_NUM_PORTS]; }; static struct pwm_data pwm_context; #ifdef CONFIG_PWM_QMSI_API_REENTRANCY #define RP_GET(dev) (&((struct pwm_data *)(dev->driver_data))->sem) #else #define RP_GET(dev) (NULL) #endif static int __set_one_port(struct device *dev, qm_pwm_t id, u32_t pwm, u32_t on, u32_t off) { qm_pwm_config_t cfg; int ret_val = 0; if (IS_ENABLED(CONFIG_PWM_QMSI_API_REENTRANCY)) { k_sem_take(RP_GET(dev), K_FOREVER); } /* Disable timer to prevent any output */ qm_pwm_stop(id, pwm); if (on == 0) { /* stop PWM if so specified */ goto pwm_set_port_return; } /** * off period must be more than zero. Otherwise, the PWM pin will be * turned off. Let's use the minimum value which is 1 for this case. */ if (off == 0) { off = 1; } /* PWM mode, user-defined count mode, timer disabled */ cfg.mode = QM_PWM_MODE_PWM; /* No interrupts */ cfg.mask_interrupt = true; cfg.callback = NULL; cfg.callback_data = NULL; /* Data for the timer to stay high and low */ cfg.hi_count = on; cfg.lo_count = off; if (qm_pwm_set_config(id, pwm, &cfg) != 0) { ret_val = -EIO; goto pwm_set_port_return; } /* Enable timer so it starts running and counting */ qm_pwm_start(id, pwm); pwm_set_port_return: if (IS_ENABLED(CONFIG_PWM_QMSI_API_REENTRANCY)) { k_sem_give(RP_GET(dev)); } return ret_val; } /* * Set the period and pulse width for a PWM pin. * * For example, with a nominal system clock of 32MHz, each count represents * 31.25ns (e.g. period = 100 means the pulse is to repeat every 3125ns). The * duration of one count depends on system clock. Refer to the hardware manual * for more information. * * Parameters * dev: Pointer to PWM device structure * pwm: PWM port number to set * period_cycles: Period (in timer count) * pulse_cycles: Pulse width (in timer count). * * return 0, or negative errno code */ static int pwm_qmsi_pin_set(struct device *dev, u32_t pwm, u32_t period_cycles, u32_t pulse_cycles) { u32_t high, low; if (pwm >= CONFIG_PWM_QMSI_NUM_PORTS) { return -EINVAL; } if (period_cycles == 0 || pulse_cycles > period_cycles) { return -EINVAL; } high = pulse_cycles; low = period_cycles - pulse_cycles; /* * low must be more than zero. Otherwise, the PWM pin will be * turned off. Let's make sure low is always more than zero. */ if (low == 0) { high--; low = 1; } return __set_one_port(dev, QM_PWM_0, pwm, high, low); } /* * Get the clock rate (cycles per second) for a PWM pin. * * Parameters * dev: Pointer to PWM device structure * pwm: PWM port number * cycles: Pointer to the memory to store clock rate (cycles per second) * * return 0, or negative errno code */ static int pwm_qmsi_get_cycles_per_sec(struct device *dev, u32_t pwm, u64_t *cycles) { if (cycles == NULL) { return -EINVAL; } *cycles = (u64_t)clk_sys_get_ticks_per_us() * USEC_PER_SEC; return 0; } static const struct pwm_driver_api pwm_qmsi_drv_api_funcs = { .pin_set = pwm_qmsi_pin_set, .get_cycles_per_sec = pwm_qmsi_get_cycles_per_sec, }; #ifdef CONFIG_DEVICE_POWER_MANAGEMENT static void pwm_qmsi_set_power_state(struct device *dev, u32_t power_state) { struct pwm_data *context = dev->driver_data; context->device_power_state = power_state; } #else #define pwm_qmsi_set_power_state(...) #endif static int pwm_qmsi_init(struct device *dev) { struct pwm_data *context = dev->driver_data; u32_t *channel_period = context->channel_period; for (int i = 0; i < CONFIG_PWM_QMSI_NUM_PORTS; i++) { channel_period[i] = DEFAULT_PERIOD * HW_CLOCK_CYCLES_PER_USEC; } clk_periph_enable(CLK_PERIPH_PWM_REGISTER | CLK_PERIPH_CLK); if (IS_ENABLED(CONFIG_PWM_QMSI_API_REENTRANCY)) { k_sem_init(RP_GET(dev), 1, UINT_MAX); } pwm_qmsi_set_power_state(dev, DEVICE_PM_ACTIVE_STATE); return 0; } #ifdef CONFIG_DEVICE_POWER_MANAGEMENT static qm_pwm_context_t pwm_ctx; static u32_t pwm_qmsi_get_power_state(struct device *dev) { struct pwm_data *context = dev->driver_data; return context->device_power_state; } static int pwm_qmsi_suspend(struct device *dev) { qm_pwm_save_context(QM_PWM_0, &pwm_ctx); pwm_qmsi_set_power_state(dev, DEVICE_PM_SUSPEND_STATE); return 0; } static int pwm_qmsi_resume_from_suspend(struct device *dev) { qm_pwm_restore_context(QM_PWM_0, &pwm_ctx); pwm_qmsi_set_power_state(dev, DEVICE_PM_ACTIVE_STATE); return 0; } /* * Implements the driver control management functionality * the *context may include IN data or/and OUT data */ static int pwm_qmsi_device_ctrl(struct device *dev, u32_t ctrl_command, void *context) { if (ctrl_command == DEVICE_PM_SET_POWER_STATE) { if (*((u32_t *)context) == DEVICE_PM_SUSPEND_STATE) { return pwm_qmsi_suspend(dev); } else if (*((u32_t *)context) == DEVICE_PM_ACTIVE_STATE) { return pwm_qmsi_resume_from_suspend(dev); } } else if (ctrl_command == DEVICE_PM_GET_POWER_STATE) { *((u32_t *)context) = pwm_qmsi_get_power_state(dev); return 0; } return 0; } #endif DEVICE_DEFINE(pwm_qmsi_0, CONFIG_PWM_QMSI_DEV_NAME, pwm_qmsi_init, pwm_qmsi_device_ctrl, &pwm_context, NULL, POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEVICE, &pwm_qmsi_drv_api_funcs);