diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/lpc176x/Kconfig | 1 | ||||
| -rw-r--r-- | src/lpc176x/Makefile | 1 | ||||
| -rw-r--r-- | src/lpc176x/gpio.h | 7 | ||||
| -rw-r--r-- | src/lpc176x/hard_pwm.c | 97 | ||||
| -rw-r--r-- | src/lpc176x/internal.h | 1 |
5 files changed, 107 insertions, 0 deletions
diff --git a/src/lpc176x/Kconfig b/src/lpc176x/Kconfig index 60c22fde..4fef74cc 100644 --- a/src/lpc176x/Kconfig +++ b/src/lpc176x/Kconfig @@ -12,6 +12,7 @@ config LPC_SELECT select HAVE_GPIO_BITBANGING select HAVE_STRICT_TIMING select HAVE_CHIPID + select HAVE_GPIO_HARD_PWM config BOARD_DIRECTORY string diff --git a/src/lpc176x/Makefile b/src/lpc176x/Makefile index b9fd454f..7ed80b26 100644 --- a/src/lpc176x/Makefile +++ b/src/lpc176x/Makefile @@ -22,6 +22,7 @@ src-$(CONFIG_HAVE_GPIO_SPI) += lpc176x/spi.c src-$(CONFIG_USBSERIAL) += lpc176x/usbserial.c lpc176x/chipid.c src-$(CONFIG_USBSERIAL) += generic/usb_cdc.c src-$(CONFIG_SERIAL) += lpc176x/serial.c generic/serial_irq.c +src-$(CONFIG_HAVE_GPIO_HARD_PWM) += lpc176x/hard_pwm.c # Build the additional bin output file target-y += $(OUT)klipper.bin diff --git a/src/lpc176x/gpio.h b/src/lpc176x/gpio.h index 482e0ce5..e03afbb4 100644 --- a/src/lpc176x/gpio.h +++ b/src/lpc176x/gpio.h @@ -21,6 +21,13 @@ struct gpio_in gpio_in_setup(uint8_t pin, int8_t pull_up); void gpio_in_reset(struct gpio_in g, int8_t pull_up); uint8_t gpio_in_read(struct gpio_in g); +struct gpio_pwm { + void *reg; + uint8_t channel; +}; +struct gpio_pwm gpio_pwm_setup(uint8_t pin, uint32_t cycle_time, uint8_t val); +void gpio_pwm_write(struct gpio_pwm g, uint32_t val); + struct gpio_adc { uint32_t chan; }; diff --git a/src/lpc176x/hard_pwm.c b/src/lpc176x/hard_pwm.c new file mode 100644 index 00000000..934ecf1a --- /dev/null +++ b/src/lpc176x/hard_pwm.c @@ -0,0 +1,97 @@ +// Hardware PWM support on lpc176x +// +// Copyright (C) 2021 Michael Kurz <michi.kurz@gmail.com> +// +// This file may be distributed under the terms of the GNU GPLv3 license. + +#include "autoconf.h" // CONFIG_CLOCK_FREQ +#include "board/irq.h" // irq_save +#include "command.h" // shutdown +#include "gpio.h" // gpio_pwm_write +#include "internal.h" // GPIO +#include "sched.h" // sched_shutdown + +#define MAX_PWM 255 +DECL_CONSTANT("PWM_MAX", MAX_PWM); + +struct gpio_pwm_info { + uint8_t pin, channel, function; + void *reg; +}; + +static const struct gpio_pwm_info pwm_regs[] = { + {GPIO(1, 18), 1, 2, (void*)&LPC_PWM1->MR1}, + {GPIO(2, 0), 1, 1, (void*)&LPC_PWM1->MR1}, + {GPIO(1, 20), 2, 2, (void*)&LPC_PWM1->MR2}, + {GPIO(2, 1), 2, 1, (void*)&LPC_PWM1->MR2}, + {GPIO(3, 25), 2, 3, (void*)&LPC_PWM1->MR2}, + {GPIO(1, 21), 3, 2, (void*)&LPC_PWM1->MR3}, + {GPIO(2, 2), 3, 1, (void*)&LPC_PWM1->MR3}, + {GPIO(3, 26), 3, 3, (void*)&LPC_PWM1->MR3}, + {GPIO(1, 23), 4, 2, (void*)&LPC_PWM1->MR4}, + {GPIO(2, 3), 4, 1, (void*)&LPC_PWM1->MR4}, + {GPIO(1, 24), 5, 2, (void*)&LPC_PWM1->MR5}, + {GPIO(2, 4), 5, 1, (void*)&LPC_PWM1->MR5}, + {GPIO(1, 26), 6, 2, (void*)&LPC_PWM1->MR6}, + {GPIO(2, 5), 6, 1, (void*)&LPC_PWM1->MR6} +}; + +struct gpio_pwm +gpio_pwm_setup(uint8_t pin, uint32_t cycle_time, uint8_t val) { + // Find pin in pwm_regs table + const struct gpio_pwm_info* p = pwm_regs; + for (;; p++) { + if (p >= &pwm_regs[ARRAY_SIZE(pwm_regs)]) + shutdown("Not a valid PWM pin"); + if (p->pin == pin) + break; + } + + // Map cycle_time to pwm clock divisor + uint32_t clock_div = CONFIG_CLOCK_FREQ / get_pclock_frequency(PCLK_PWM1); + uint32_t prescaler = (cycle_time / clock_div) / (MAX_PWM - 1); + if (prescaler > 0) { + prescaler -= 1; + } + + gpio_peripheral(p->pin, p->function, 0); + + // Enable clock + if (!is_enabled_pclock(PCLK_PWM1)) { + enable_pclock(PCLK_PWM1); + } + + if (LPC_PWM1->TCR & 1) { + if (LPC_PWM1->PR != prescaler) { + shutdown("PWM already programmed at different speed"); + } + } else { + LPC_PWM1->PR = (uint16_t) prescaler; + LPC_PWM1->MCR = 2; + LPC_PWM1->MR0 = MAX_PWM - 1; + LPC_PWM1->LER |= 1 << 0; + LPC_PWM1->TCR = 0x2; // Reset PWM + LPC_PWM1->TCR = 0x8; // Enable PWM mode + } + + if (LPC_PWM1->PCR & (1 << (p->channel + 8))) { + shutdown("PWM output already in use"); + } + + struct gpio_pwm channel = {.reg = p->reg, .channel = p->channel}; + gpio_pwm_write(channel, val); + + // Enable channel + LPC_PWM1->PCR |= (1 << (p->channel + 8)); + + // Enable PWM peripheral + LPC_PWM1->TCR |= 0x1; + + return channel; +} + +void +gpio_pwm_write(struct gpio_pwm g, uint32_t val) { + *(volatile uint32_t*) g.reg = val; + LPC_PWM1->LER |= (1 << g.channel); +} diff --git a/src/lpc176x/internal.h b/src/lpc176x/internal.h index 84b7ac84..d46bf66d 100644 --- a/src/lpc176x/internal.h +++ b/src/lpc176x/internal.h @@ -10,6 +10,7 @@ #define PCLK_TIMER0 1 #define PCLK_UART0 3 +#define PCLK_PWM1 6 #define PCLK_I2C0 7 #define PCLK_SSP1 10 #define PCLK_ADC 12 |