diff options
| -rw-r--r-- | src/Kconfig | 3 | ||||
| -rw-r--r-- | src/Makefile | 1 | ||||
| -rw-r--r-- | src/avr/Kconfig | 1 | ||||
| -rw-r--r-- | src/lcd_st7920.c | 121 |
4 files changed, 126 insertions, 0 deletions
diff --git a/src/Kconfig b/src/Kconfig index c28cec14..564073eb 100644 --- a/src/Kconfig +++ b/src/Kconfig @@ -36,6 +36,9 @@ config HAVE_GPIO_SPI config HAVE_GPIO_HARD_PWM bool default n +config HAVE_USER_INTERFACE + bool + default n config NO_UNSTEP_DELAY # Slow micro-controllers do not require a delay before returning a diff --git a/src/Makefile b/src/Makefile index ce626faa..b316bb66 100644 --- a/src/Makefile +++ b/src/Makefile @@ -5,3 +5,4 @@ src-$(CONFIG_HAVE_GPIO) += gpiocmds.c stepper.c endstop.c src-$(CONFIG_HAVE_GPIO_ADC) += adccmds.c src-$(CONFIG_HAVE_GPIO_SPI) += spicmds.c src-$(CONFIG_HAVE_GPIO_HARD_PWM) += pwmcmds.c +src-$(CONFIG_HAVE_USER_INTERFACE) += lcd_st7920.c diff --git a/src/avr/Kconfig b/src/avr/Kconfig index 9a4500c1..77f002e2 100644 --- a/src/avr/Kconfig +++ b/src/avr/Kconfig @@ -9,6 +9,7 @@ config AVR_SELECT select HAVE_GPIO_ADC select HAVE_GPIO_SPI select HAVE_GPIO_HARD_PWM + select HAVE_USER_INTERFACE select NO_UNSTEP_DELAY config BOARD_DIRECTORY diff --git a/src/lcd_st7920.c b/src/lcd_st7920.c new file mode 100644 index 00000000..4351d6ac --- /dev/null +++ b/src/lcd_st7920.c @@ -0,0 +1,121 @@ +// Commands for sending messages to an st7920 lcd driver +// +// Copyright (C) 2018 Kevin O'Connor <kevin@koconnor.net> +// +// This file may be distributed under the terms of the GNU GPLv3 license. + +#include "basecmd.h" // oid_alloc +#include "board/gpio.h" // gpio_out_write +#include "board/irq.h" // irq_poll +#include "board/misc.h" // timer_from_us +#include "command.h" // DECL_COMMAND +#include "sched.h" // DECL_SHUTDOWN + +struct st7920 { + uint32_t last_cmd_time, cmd_wait_ticks; + struct gpio_out sclk, sid; +}; + + +/**************************************************************** + * Transmit functions + ****************************************************************/ + +#define SYNC_CMD 0xf8 +#define SYNC_DATA 0xfa + +// Write eight bits to the st7920 via the serial interface +static void +st7920_xmit_byte(struct st7920 *s, uint8_t data) +{ + struct gpio_out sclk = s->sclk, sid = s->sid; + uint8_t i; + for (i=0; i<8; i++) { + if (data & 0x80) { + gpio_out_toggle(sid); + data = ~data; + } + gpio_out_toggle(sclk); + data <<= 1; + gpio_out_toggle(sclk); + } +} + +// Transmit a series of command bytes to the chip +static void +st7920_xmit(struct st7920 *s, uint8_t count, uint8_t *cmds) +{ + uint32_t last_cmd_time=s->last_cmd_time, cmd_wait_ticks=s->cmd_wait_ticks; + while (count--) { + uint8_t cmd = *cmds++; + st7920_xmit_byte(s, cmd & 0xf0); + // Can't complete transfer until delay complete + while (timer_read_time() - last_cmd_time < cmd_wait_ticks) + irq_poll(); + st7920_xmit_byte(s, cmd << 4); + last_cmd_time = timer_read_time(); + } + s->last_cmd_time = last_cmd_time; +} + + +/**************************************************************** + * Interface + ****************************************************************/ + +void +command_config_st7920(uint32_t *args) +{ + struct st7920 *s = oid_alloc(args[0], command_config_st7920, sizeof(*s)); + s->sclk = gpio_out_setup(args[2], 0); + s->sid = gpio_out_setup(args[3], 0); + gpio_out_setup(args[1], 1); + + // Calibrate cmd_wait_ticks + st7920_xmit_byte(s, SYNC_CMD); + st7920_xmit_byte(s, 0x20); + irq_disable(); + uint32_t start = timer_read_time(); + st7920_xmit_byte(s, 0x00); + uint32_t end = timer_read_time(); + irq_enable(); + s->last_cmd_time = end; + uint32_t diff = end - start, delay_ticks = args[4]; + if (delay_ticks > diff) + s->cmd_wait_ticks = delay_ticks - diff; +} +DECL_COMMAND(command_config_st7920, + "config_st7920 oid=%c cs_pin=%u sclk_pin=%u sid_pin=%u" + " delay_ticks=%u"); + +void +command_st7920_send_cmds(uint32_t *args) +{ + struct st7920 *s = oid_lookup(args[0], command_config_st7920); + st7920_xmit_byte(s, SYNC_CMD); + uint8_t len = args[1], *cmds = (void*)(size_t)args[2]; + st7920_xmit(s, len, cmds); +} +DECL_COMMAND(command_st7920_send_cmds, "st7920_send_cmds oid=%c cmds=%*s"); + +void +command_st7920_send_data(uint32_t *args) +{ + struct st7920 *s = oid_lookup(args[0], command_config_st7920); + st7920_xmit_byte(s, SYNC_DATA); + uint8_t len = args[1], *data = (void*)(size_t)args[2]; + st7920_xmit(s, len, data); +} +DECL_COMMAND(command_st7920_send_data, "st7920_send_data oid=%c data=%*s"); + +void +st7920_shutdown(void) +{ + uint8_t i; + struct st7920 *s; + foreach_oid(i, s, command_config_st7920) { + gpio_out_write(s->sclk, 0); + gpio_out_write(s->sid, 0); + } +} +DECL_SHUTDOWN(st7920_shutdown); |