diff options
Diffstat (limited to 'roms/u-boot/board/friendlyarm/nanopi2/onewire.c')
| -rw-r--r-- | roms/u-boot/board/friendlyarm/nanopi2/onewire.c | 307 |
1 files changed, 307 insertions, 0 deletions
diff --git a/roms/u-boot/board/friendlyarm/nanopi2/onewire.c b/roms/u-boot/board/friendlyarm/nanopi2/onewire.c new file mode 100644 index 000000000..fb356639b --- /dev/null +++ b/roms/u-boot/board/friendlyarm/nanopi2/onewire.c @@ -0,0 +1,307 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) Guangzhou FriendlyARM Computer Tech. Co., Ltd. + * (http://www.friendlyarm.com) + */ + +#include <config.h> +#include <common.h> +#include <errno.h> +#include <asm/io.h> +#include <asm/arch/clk.h> +#include <i2c.h> +#include <pwm.h> + +#include <irq_func.h> + +#include <asm/arch/nexell.h> +#include <asm/arch/nx_gpio.h> + +#ifndef NSEC_PER_SEC +#define NSEC_PER_SEC 1000000000L +#endif + +#define SAMPLE_BPS 9600 +#define SAMPLE_IN_US 101 /* (1000000 / BPS) */ + +#define REQ_INFO 0x60U +#define REQ_BL 0x80U + +#define BUS_I2C 0x18 +#define ONEWIRE_I2C_BUS 2 +#define ONEWIRE_I2C_ADDR 0x2f + +static int bus_type = -1; +static int lcd_id = -1; +static unsigned short lcd_fwrev; +static int current_brightness = -1; +#if CONFIG_IS_ENABLED(DM_I2C) +static struct udevice *i2c_dev; +#endif + +/* debug */ +#if (0) +#define DBGOUT(msg...) do { printf("onewire: " msg); } while (0) +#else +#define DBGOUT(msg...) do {} while (0) +#endif + +/* based on web page from http://lfh1986.blogspot.com */ +static unsigned char crc8_ow(unsigned int v, unsigned int len) +{ + unsigned char crc = 0xACU; + + while (len--) { + if ((crc & 0x80U) != 0) { + crc <<= 1; + crc ^= 0x7U; + } else { + crc <<= 1; + } + if ((v & (1U << 31)) != 0) + crc ^= 0x7U; + v <<= 1; + } + return crc; +} + +/* GPIO helpers */ +#define __IO_GRP 2 /* GPIOC15 */ +#define __IO_IDX 15 + +static inline void set_pin_as_input(void) +{ + nx_gpio_set_output_enable(__IO_GRP, __IO_IDX, 0); +} + +static inline void set_pin_as_output(void) +{ + nx_gpio_set_output_enable(__IO_GRP, __IO_IDX, 1); +} + +static inline void set_pin_value(int v) +{ + nx_gpio_set_output_value(__IO_GRP, __IO_IDX, !!v); +} + +static inline int get_pin_value(void) +{ + return nx_gpio_get_input_value(__IO_GRP, __IO_IDX); +} + +/* Timer helpers */ +#define PWM_CH 3 +#define PWM_TCON (PHY_BASEADDR_PWM + 0x08) +#define PWM_TCON_START (1 << 16) +#define PWM_TINT_CSTAT (PHY_BASEADDR_PWM + 0x44) + +static int onewire_init_timer(void) +{ + int period_ns = NSEC_PER_SEC / SAMPLE_BPS; + + /* range: 1080~1970 */ + period_ns -= 1525; + + return pwm_config(PWM_CH, period_ns >> 1, period_ns); +} + +static void wait_one_tick(void) +{ + unsigned int tcon; + + tcon = readl(PWM_TCON); + tcon |= PWM_TCON_START; + writel(tcon, PWM_TCON); + + while (1) { + if (readl(PWM_TINT_CSTAT) & (1 << (5 + PWM_CH))) + break; + } + + writel((1 << (5 + PWM_CH)), PWM_TINT_CSTAT); + + tcon &= ~PWM_TCON_START; + writel(tcon, PWM_TCON); +} + +/* Session handler */ +static int onewire_session(unsigned char req, unsigned char res[]) +{ + unsigned int Req; + unsigned int *Res; + int ints = disable_interrupts(); + int i; + int ret; + + Req = (req << 24) | (crc8_ow(req << 24, 8) << 16); + Res = (unsigned int *)res; + + set_pin_value(1); + set_pin_as_output(); + for (i = 0; i < 60; i++) + wait_one_tick(); + + set_pin_value(0); + for (i = 0; i < 2; i++) + wait_one_tick(); + + for (i = 0; i < 16; i++) { + int v = !!(Req & (1U << 31)); + + Req <<= 1; + set_pin_value(v); + wait_one_tick(); + } + + wait_one_tick(); + set_pin_as_input(); + wait_one_tick(); + for (i = 0; i < 32; i++) { + (*Res) <<= 1; + (*Res) |= get_pin_value(); + wait_one_tick(); + } + set_pin_value(1); + set_pin_as_output(); + + if (ints) + enable_interrupts(); + + ret = crc8_ow(*Res, 24) == res[0]; + DBGOUT("req = %02X, res = %02X%02X%02X%02X, ret = %d\n", + req, res[3], res[2], res[1], res[0], ret); + + return ret; +} + +static int onewire_i2c_do_request(unsigned char req, unsigned char *buf) +{ + unsigned char tx[4]; + int ret; + + tx[0] = req; + tx[1] = crc8_ow(req << 24, 8); + +#if CONFIG_IS_ENABLED(DM_I2C) + if (dm_i2c_write(i2c_dev, 0, tx, 2)) + return -EIO; + + if (!buf) + return 0; + + if (dm_i2c_read(i2c_dev, 0, buf, 4)) + return -EIO; +#else + if (i2c_write(ONEWIRE_I2C_ADDR, 0, 0, tx, 2)) + return -EIO; + + if (!buf) /* NO READ */ + return 0; + + if (i2c_read(ONEWIRE_I2C_ADDR, 0, 0, buf, 4)) + return -EIO; +#endif + + ret = crc8_ow((buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8), 24); + DBGOUT("req = %02X, res = %02X%02X%02X%02X, ret = %02x\n", + req, buf[0], buf[1], buf[2], buf[3], ret); + + return (ret == buf[3]) ? 0 : -EIO; +} + +static void onewire_i2c_init(void) +{ + unsigned char buf[4]; + int ret; + +#if CONFIG_IS_ENABLED(DM_I2C) + ret = i2c_get_chip_for_busnum(ONEWIRE_I2C_BUS, + ONEWIRE_I2C_ADDR, 0, &i2c_dev); +#else + i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE); + i2c_set_bus_num(ONEWIRE_I2C_BUS); + + ret = i2c_probe(ONEWIRE_I2C_ADDR); +#endif + if (ret) + return; + + ret = onewire_i2c_do_request(REQ_INFO, buf); + if (!ret) { + lcd_id = buf[0]; + lcd_fwrev = buf[1] * 0x100 + buf[2]; + bus_type = BUS_I2C; + } +} + +void onewire_init(void) +{ + /* GPIO, Pull-off */ + nx_gpio_set_pad_function(__IO_GRP, __IO_IDX, 1); + nx_gpio_set_pull_mode(__IO_GRP, __IO_IDX, 2); + + onewire_init_timer(); + onewire_i2c_init(); +} + +int onewire_get_info(unsigned char *lcd, unsigned short *fw_ver) +{ + unsigned char res[4]; + int i; + + if (bus_type == BUS_I2C && lcd_id > 0) { + *lcd = lcd_id; + *fw_ver = lcd_fwrev; + return 0; + } + + for (i = 0; i < 3; i++) { + if (onewire_session(REQ_INFO, res)) { + *lcd = res[3]; + *fw_ver = res[2] * 0x100 + res[1]; + lcd_id = *lcd; + DBGOUT("lcd = %d, fw_ver = %x\n", *lcd, *fw_ver); + return 0; + } + } + + /* LCD unknown or not connected */ + *lcd = 0; + *fw_ver = -1; + + return -1; +} + +int onewire_get_lcd_id(void) +{ + return lcd_id; +} + +int onewire_set_backlight(int brightness) +{ + unsigned char res[4]; + int i; + + if (brightness == current_brightness) + return 0; + + if (brightness > 127) + brightness = 127; + else if (brightness < 0) + brightness = 0; + + if (bus_type == BUS_I2C) { + onewire_i2c_do_request((REQ_BL | brightness), NULL); + current_brightness = brightness; + return 0; + } + + for (i = 0; i < 3; i++) { + if (onewire_session((REQ_BL | brightness), res)) { + current_brightness = brightness; + return 0; + } + } + + return -1; +} |