diff options
Diffstat (limited to 'board/work-microwave/work_92105/work_92105_display.c')
| -rw-r--r-- | board/work-microwave/work_92105/work_92105_display.c | 349 |
1 files changed, 349 insertions, 0 deletions
diff --git a/board/work-microwave/work_92105/work_92105_display.c b/board/work-microwave/work_92105/work_92105_display.c new file mode 100644 index 0000000000..c8b10131f9 --- /dev/null +++ b/board/work-microwave/work_92105/work_92105_display.c @@ -0,0 +1,349 @@ +/* + * work_92105 display support + * + * (C) Copyright 2014 DENX Software Engineering GmbH + * Written-by: Albert ARIBAUD <albert.aribaud@3adev.fr> + * + * The work_92105 display is a HD44780-compatible module + * controlled through a MAX6957AAX SPI port expander, two + * MAX518 I2C DACs and native LPC32xx GPO 15. + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <asm/arch/sys_proto.h> +#include <asm/arch/cpu.h> +#include <asm/arch/emc.h> +#include <asm/gpio.h> +#include <spi.h> +#include <i2c.h> +#include <version.h> +#include <vsprintf.h> + +/* + * GPO 15 in port 3 is gpio 3*32+15 = 111 + */ + +#define GPO_15 111 + +/** + * MAX6957AAX registers that we will be using + */ + +#define MAX6957_CONF 0x04 + +#define MAX6957_CONF_08_11 0x0A +#define MAX6957_CONF_12_15 0x0B +#define MAX6957_CONF_16_19 0x0C + +/** + * Individual gpio ports (one per gpio) to HD44780 + */ + +#define MAX6957AAX_HD44780_RS 0x29 +#define MAX6957AAX_HD44780_R_W 0x2A +#define MAX6957AAX_HD44780_EN 0x2B +#define MAX6957AAX_HD44780_DATA 0x4C + +/** + * Display controller instructions + */ + +/* Function set: eight bits, two lines, 8-dot font */ +#define HD44780_FUNCTION_SET 0x38 + +/* Display ON / OFF: turn display on */ +#define HD44780_DISPLAY_ON_OFF_CONTROL 0x0C + +/* Entry mode: increment */ +#define HD44780_ENTRY_MODE_SET 0x06 + +/* Clear */ +#define HD44780_CLEAR_DISPLAY 0x01 + +/* Set DDRAM addr (to be ORed with exact address) */ +#define HD44780_SET_DDRAM_ADDR 0x80 + +/* Set CGRAM addr (to be ORed with exact address) */ +#define HD44780_SET_CGRAM_ADDR 0x40 + +/** + * Default value for contrats + */ + +#define CONTRAST_DEFAULT 25 + +/** + * Define slave as a module-wide local to save passing it around, + * plus we will need it after init for the "hd44780" command. + */ + +static struct spi_slave *slave; + +/* + * Write a value into a MAX6957AAX register. + */ + +static void max6957aax_write(uint8_t reg, uint8_t value) +{ + uint8_t dout[2]; + + dout[0] = reg; + dout[1] = value; + gpio_set_value(GPO_15, 0); + /* do SPI read/write (passing din==dout is OK) */ + spi_xfer(slave, 16, dout, dout, SPI_XFER_BEGIN | SPI_XFER_END); + gpio_set_value(GPO_15, 1); +} + +/* + * Read a value from a MAX6957AAX register. + * + * According to the MAX6957AAX datasheet, we should release the chip + * select halfway through the read sequence, when the actual register + * value is read; but the WORK_92105 hardware prevents the MAX6957AAX + * SPI OUT from reaching the LPC32XX SIP MISO if chip is not selected. + * so let's release the CS an hold it again while reading the result. + */ + +static uint8_t max6957aax_read(uint8_t reg) +{ + uint8_t dout[2], din[2]; + + /* send read command */ + dout[0] = reg | 0x80; /* set bit 7 to indicate read */ + dout[1] = 0; + gpio_set_value(GPO_15, 0); + /* do SPI read/write (passing din==dout is OK) */ + spi_xfer(slave, 16, dout, dout, SPI_XFER_BEGIN | SPI_XFER_END); + /* latch read command */ + gpio_set_value(GPO_15, 1); + /* read register -- din = noop on xmit, din[1] = reg on recv */ + din[0] = 0; + din[1] = 0; + gpio_set_value(GPO_15, 0); + /* do SPI read/write (passing din==dout is OK) */ + spi_xfer(slave, 16, din, din, SPI_XFER_BEGIN | SPI_XFER_END); + /* end of read. */ + gpio_set_value(GPO_15, 1); + return din[1]; +} + +static void hd44780_instruction(unsigned long instruction) +{ + max6957aax_write(MAX6957AAX_HD44780_RS, 0); + max6957aax_write(MAX6957AAX_HD44780_R_W, 0); + max6957aax_write(MAX6957AAX_HD44780_EN, 1); + max6957aax_write(MAX6957AAX_HD44780_DATA, instruction); + max6957aax_write(MAX6957AAX_HD44780_EN, 0); + /* HD44780 takes 37 us for most instructions, 1520 for clear */ + if (instruction == HD44780_CLEAR_DISPLAY) + udelay(2000); + else + udelay(100); +} + +static void hd44780_write_char(char c) +{ + max6957aax_write(MAX6957AAX_HD44780_RS, 1); + max6957aax_write(MAX6957AAX_HD44780_R_W, 0); + max6957aax_write(MAX6957AAX_HD44780_EN, 1); + max6957aax_write(MAX6957AAX_HD44780_DATA, c); + max6957aax_write(MAX6957AAX_HD44780_EN, 0); + /* HD44780 takes 37 us to write to DDRAM or CGRAM */ + udelay(100); +} + +static void hd44780_write_str(char *s) +{ + max6957aax_write(MAX6957AAX_HD44780_RS, 1); + max6957aax_write(MAX6957AAX_HD44780_R_W, 0); + while (*s) { + max6957aax_write(MAX6957AAX_HD44780_EN, 1); + max6957aax_write(MAX6957AAX_HD44780_DATA, *s); + max6957aax_write(MAX6957AAX_HD44780_EN, 0); + s++; + /* HD44780 takes 37 us to write to DDRAM or CGRAM */ + udelay(100); + } +} + +/* + * Existing user code might expect these custom characters to be + * recognized and displayed on the LCD + */ + +static u8 char_gen_chars[] = { + /* #8, empty rectangle */ + 0x1F, 0x11, 0x11, 0x11, 0x11, 0x11, 0x11, 0x1F, + /* #9, filled right arrow */ + 0x10, 0x18, 0x1C, 0x1E, 0x1C, 0x18, 0x10, 0x00, + /* #10, filled left arrow */ + 0x01, 0x03, 0x07, 0x0F, 0x07, 0x03, 0x01, 0x00, + /* #11, up and down arrow */ + 0x04, 0x0E, 0x1F, 0x00, 0x00, 0x1F, 0x0E, 0x04, + /* #12, plus/minus */ + 0x04, 0x04, 0x1F, 0x04, 0x04, 0x00, 0x1F, 0x00, + /* #13, fat exclamation mark */ + 0x06, 0x06, 0x06, 0x06, 0x00, 0x06, 0x06, 0x00, + /* #14, empty square */ + 0x00, 0x1F, 0x11, 0x11, 0x11, 0x1F, 0x00, 0x00, + /* #15, struck out square */ + 0x00, 0x1F, 0x19, 0x15, 0x13, 0x1F, 0x00, 0x00, +}; + +static void hd44780_init_char_gen(void) +{ + int i; + + hd44780_instruction(HD44780_SET_CGRAM_ADDR); + + for (i = 0; i < sizeof(char_gen_chars); i++) + hd44780_write_char(char_gen_chars[i]); + + hd44780_instruction(HD44780_SET_DDRAM_ADDR); +} + +void work_92105_display_init(void) +{ + int claim_err; + char *display_contrast_str; + uint8_t display_contrast = CONTRAST_DEFAULT; + uint8_t enable_backlight = 0x96; + + slave = spi_setup_slave(0, 0, 500000, 0); + + if (!slave) { + printf("Failed to set up SPI slave\n"); + return; + } + + claim_err = spi_claim_bus(slave); + + if (claim_err) + debug("Failed to claim SPI bus: %d\n", claim_err); + + /* enable backlight */ + i2c_write(0x2c, 0x01, 1, &enable_backlight, 1); + + /* set display contrast */ + display_contrast_str = getenv("fwopt_dispcontrast"); + if (display_contrast_str) + display_contrast = simple_strtoul(display_contrast_str, + NULL, 10); + i2c_write(0x2c, 0x00, 1, &display_contrast, 1); + + /* request GPO_15 as an output initially set to 1 */ + gpio_request(GPO_15, "MAX6957_nCS"); + gpio_direction_output(GPO_15, 1); + + /* enable MAX6957 portexpander */ + max6957aax_write(MAX6957_CONF, 0x01); + /* configure pin 8 as input, pins 9..19 as outputs */ + max6957aax_write(MAX6957_CONF_08_11, 0x56); + max6957aax_write(MAX6957_CONF_12_15, 0x55); + max6957aax_write(MAX6957_CONF_16_19, 0x55); + + /* initialize HD44780 */ + max6957aax_write(MAX6957AAX_HD44780_EN, 0); + hd44780_instruction(HD44780_FUNCTION_SET); + hd44780_instruction(HD44780_DISPLAY_ON_OFF_CONTROL); + hd44780_instruction(HD44780_ENTRY_MODE_SET); + + /* write custom character glyphs */ + hd44780_init_char_gen(); + + /* Show U-Boot version, date and time as a sign-of-life */ + hd44780_instruction(HD44780_CLEAR_DISPLAY); + hd44780_instruction(HD44780_SET_DDRAM_ADDR | 0); + hd44780_write_str(U_BOOT_VERSION); + hd44780_instruction(HD44780_SET_DDRAM_ADDR | 64); + hd44780_write_str(U_BOOT_DATE); + hd44780_instruction(HD44780_SET_DDRAM_ADDR | 64 | 20); + hd44780_write_str(U_BOOT_TIME); +} + +#ifdef CONFIG_CMD_MAX6957 + +static int do_max6957aax(cmd_tbl_t *cmdtp, int flag, int argc, + char *const argv[]) +{ + int reg, val; + + if (argc != 3) + return CMD_RET_USAGE; + switch (argv[1][0]) { + case 'r': + case 'R': + reg = simple_strtoul(argv[2], NULL, 0); + val = max6957aax_read(reg); + printf("MAX6957 reg 0x%02x read 0x%02x\n", reg, val); + return 0; + default: + reg = simple_strtoul(argv[1], NULL, 0); + val = simple_strtoul(argv[2], NULL, 0); + max6957aax_write(reg, val); + printf("MAX6957 reg 0x%02x wrote 0x%02x\n", reg, val); + return 0; + } + return 1; +} + +#ifdef CONFIG_SYS_LONGHELP +static char max6957aax_help_text[] = + "max6957aax - write or read display register:\n" + "\tmax6957aax R|r reg - read display register;\n" + "\tmax6957aax reg val - write display register."; +#endif + +U_BOOT_CMD( + max6957aax, 6, 1, do_max6957aax, + "SPI MAX6957 display write/read", + max6957aax_help_text +); +#endif /* CONFIG_CMD_MAX6957 */ + +#ifdef CONFIG_CMD_HD44760 + +/* + * We need the HUSH parser because we need string arguments, and + * only HUSH can understand them. + */ + +#if !defined(CONFIG_SYS_HUSH_PARSER) +#error CONFIG_CMD_HD44760 requires CONFIG_SYS_HUSH_PARSER +#endif + +static int do_hd44780(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[]) +{ + char *cmd; + + if (argc != 3) + return CMD_RET_USAGE; + + cmd = argv[1]; + + if (strcasecmp(cmd, "cmd") == 0) + hd44780_instruction(simple_strtol(argv[2], NULL, 0)); + else if (strcasecmp(cmd, "data") == 0) + hd44780_write_char(simple_strtol(argv[2], NULL, 0)); + else if (strcasecmp(cmd, "str") == 0) + hd44780_write_str(argv[2]); + return 0; +} + +#ifdef CONFIG_SYS_LONGHELP +static char hd44780_help_text[] = + "hd44780 - control LCD driver:\n" + "\thd44780 cmd <val> - send command <val> to driver;\n" + "\thd44780 data <val> - send data <val> to driver;\n" + "\thd44780 str \"<text>\" - send \"<text>\" to driver."; +#endif + +U_BOOT_CMD( + hd44780, 6, 1, do_hd44780, + "HD44780 LCD driver control", + hd44780_help_text +); +#endif /* CONFIG_CMD_HD44780 */ |