/*
   * (C) Copyright 2013
   * Viktar Palstsiuk, Promwad, viktar.palstsiuk@promwad.com
   *
   * SPDX-License-Identifier:	GPL-2.0+
   */
  
  /*
   * Driver for Semtech SX151x SPI GPIO Expanders
   */
  
  #include <common.h>
  #include <spi.h>
  #include <sx151x.h>
  
  #ifndef CONFIG_SX151X_SPI_BUS
  #define CONFIG_SX151X_SPI_BUS 0
  #endif
  
  /*
   * The SX151x registers
   */
  
  #ifdef CONFIG_SX151X_GPIO_COUNT_8
  /* 8bit: SX1511 */
  #define SX151X_REG_DIR		0x07
  #define SX151X_REG_DATA		0x08
  #else
  /* 16bit: SX1512 */
  #define SX151X_REG_DIR		0x0F
  #define SX151X_REG_DATA		0x11
  #endif
  #define SX151X_REG_RESET	0x7D
  
  static int sx151x_spi_write(int chip, unsigned char reg, unsigned char val)
  {
  	struct spi_slave *slave;
  	unsigned char buf[2];
  	int ret;
  
  	slave = spi_setup_slave(CONFIG_SX151X_SPI_BUS, chip, 1000000,
  				SPI_MODE_0);
  	if (!slave)
  		return 0;
  
  	spi_claim_bus(slave);
  
  	buf[0] = reg;
  	buf[1] = val;
  
  	ret = spi_xfer(slave, 16, buf, NULL, SPI_XFER_BEGIN | SPI_XFER_END);
  	if (ret < 0)
  		printf("spi%d.%d write fail: can't write %02x to %02x: %d
  ",
  			CONFIG_SX151X_SPI_BUS, chip, val, reg, ret);
  	else
  		printf("spi%d.%d write 0x%02x to register 0x%02x
  ",
  		       CONFIG_SX151X_SPI_BUS, chip, val, reg);
  	spi_release_bus(slave);
  	spi_free_slave(slave);
  
  	return ret;
  }
  
  static int sx151x_spi_read(int chip, unsigned char reg)
  {
  	struct spi_slave *slave;
  	int ret;
  
  	slave = spi_setup_slave(CONFIG_SX151X_SPI_BUS, chip, 1000000,
  				SPI_MODE_0);
  	if (!slave)
  		return 0;
  
  	spi_claim_bus(slave);
  
  	ret = spi_w8r8(slave, reg | 0x80);
  	if (ret < 0)
  		printf("spi%d.%d read fail: can't read %02x: %d
  ",
  			CONFIG_SX151X_SPI_BUS, chip, reg, ret);
  	else
  		printf("spi%d.%d read register 0x%02x: 0x%02x
  ",
  		       CONFIG_SX151X_SPI_BUS, chip, reg, ret);
  
  	spi_release_bus(slave);
  	spi_free_slave(slave);
  
  	return ret;
  }
  
  static inline void sx151x_find_cfg(int gpio, unsigned char *reg, unsigned char *mask)
  {
  	*reg   -= gpio / 8;
  	*mask   = 1 << (gpio % 8);
  }
  
  static int sx151x_write_cfg(int chip, unsigned char gpio, unsigned char reg, int val)
  {
  	unsigned char  mask;
  	unsigned char  data;
  	int ret;
  
  	sx151x_find_cfg(gpio, &reg, &mask);
  	ret = sx151x_spi_read(chip, reg);
  	if (ret < 0)
  		return ret;
  	else
  		data = ret;
  	data &= ~mask;
  	data |= (val << (gpio % 8)) & mask;
  	return sx151x_spi_write(chip, reg, data);
  }
  
  int sx151x_get_value(int chip, int gpio)
  {
  	unsigned char  reg = SX151X_REG_DATA;
  	unsigned char  mask;
  	int ret;
  
  	sx151x_find_cfg(gpio, &reg, &mask);
  	ret = sx151x_spi_read(chip, reg);
  	if (ret >= 0)
  		ret = (ret & mask) != 0 ? 1 : 0;
  
  	return ret;
  }
  
  int sx151x_set_value(int chip, int gpio, int val)
  {
  	return sx151x_write_cfg(chip, gpio, SX151X_REG_DATA, (val ? 1 : 0));
  }
  
  int sx151x_direction_input(int chip, int gpio)
  {
  	return sx151x_write_cfg(chip, gpio, SX151X_REG_DIR, 1);
  }
  
  int sx151x_direction_output(int chip, int gpio)
  {
  	return sx151x_write_cfg(chip, gpio, SX151X_REG_DIR, 0);
  }
  
  int sx151x_reset(int chip)
  {
  	int err;
  
  	err = sx151x_spi_write(chip, SX151X_REG_RESET, 0x12);
  	if (err < 0)
  		return err;
  
  	err = sx151x_spi_write(chip, SX151X_REG_RESET, 0x34);
  	return err;
  }
  
  #ifdef CONFIG_CMD_SX151X
  
  int do_sx151x(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
  {
  	int ret = CMD_RET_USAGE, chip = 0, gpio = 0, val = 0;
  
  	if (argc < 3)
  		return CMD_RET_USAGE;
  
  	/* arg2 used as chip number */
  	chip = simple_strtoul(argv[2], NULL, 10);
  
  	if (strcmp(argv[1], "reset") == 0) {
  		ret = sx151x_reset(chip);
  		if (!ret) {
  			printf("Device at spi%d.%d was reset
  ",
  			       CONFIG_SX151X_SPI_BUS, chip);
  		}
  		return ret;
  	}
  
  	if (argc < 4)
  		return CMD_RET_USAGE;
  
  	/* arg3 used as gpio number */
  	gpio = simple_strtoul(argv[3], NULL, 10);
  
  	if (strcmp(argv[1], "get") == 0) {
  		ret = sx151x_get_value(chip, gpio);
  		if (ret < 0)
  			printf("Failed to get value at spi%d.%d gpio %d
  ",
  			       CONFIG_SX151X_SPI_BUS, chip, gpio);
  		else {
  			printf("Value at spi%d.%d gpio %d is %d
  ",
  			       CONFIG_SX151X_SPI_BUS, chip, gpio, ret);
  			ret = 0;
  		}
  		return ret;
  	}
  
  	if (argc < 5)
  		return CMD_RET_USAGE;
  
  	/* arg4 used as value or direction */
  	val = simple_strtoul(argv[4], NULL, 10);
  
  	if (strcmp(argv[1], "set") == 0) {
  		ret = sx151x_set_value(chip, gpio, val);
  		if (ret < 0)
  			printf("Failed to set value at spi%d.%d gpio %d
  ",
  			       CONFIG_SX151X_SPI_BUS, chip, gpio);
  		else
  			printf("New value at spi%d.%d gpio %d is %d
  ",
  			       CONFIG_SX151X_SPI_BUS, chip, gpio, val);
  		return ret;
  	} else if (strcmp(argv[1], "dir") == 0) {
  		if (val == 0)
  			ret = sx151x_direction_output(chip, gpio);
  		else
  			ret = sx151x_direction_input(chip, gpio);
  
  		if (ret < 0)
  			printf("Failed to set direction of spi%d.%d gpio %d
  ",
  			       CONFIG_SX151X_SPI_BUS, chip, gpio);
  		else
  			printf("New direction of spi%d.%d gpio %d is %d
  ",
  			       CONFIG_SX151X_SPI_BUS, chip, gpio, val);
  		return ret;
  	}
  
  	printf("Please see usage
  ");
  
  	return ret;
  }
  
  U_BOOT_CMD(
  	sx151x,	5,	1,	do_sx151x,
  	"sx151x gpio access",
  	"dir chip gpio 0|1
  "
  	"	- set gpio direction (0 for output, 1 for input)
  "
  	"sx151x get chip gpio
  "
  	"	- get gpio value
  "
  	"sx151x set chip gpio 0|1
  "
  	"	- set gpio value
  "
  	"sx151x reset chip
  "
  	"	- reset chip"
  );
  
  #endif /* CONFIG_CMD_SX151X */