gpio: tca642x: Add the tca642x gpio expander driver

Add the tca642x gpio expander driver

Datasheet:
http://www.ti.com/product/tca6424a

Signed-off-by: Dan Murphy <dmurphy@ti.com>

2 files changed, 334 insertions, 0 deletions

diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index af94bf5..71ddb00 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -33,6 +33,7 @@ COBJS-$(CONFIG_BCM2835_GPIO)	+= bcm2835_gpio.o
 COBJS-$(CONFIG_S3C2440_GPIO)	+= s3c2440_gpio.o
 COBJS-$(CONFIG_XILINX_GPIO)	+= xilinx_gpio.o
 COBJS-$(CONFIG_ADI_GPIO2)	+= adi_gpio2.o
+COBJS-$(CONFIG_TCA642X)		+= tca642x.o
 
 COBJS	:= $(COBJS-y)
 SRCS 	:= $(COBJS:.o=.c)
diff --git a/drivers/gpio/tca642x.c b/drivers/gpio/tca642x.c
new file mode 100644
index 0000000..6386835
--- /dev/null
+++ b/drivers/gpio/tca642x.c
@@ -0,0 +1,333 @@
+/*
+ * Copyright 2013 Texas Instruments, Inc.
+ * Author: Dan Murphy <dmurphy@ti.com>
+ *
+ * Derived work from the pca953x.c driver
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <i2c.h>
+#include <tca642x.h>
+
+/* tca642x register address definitions */
+struct tca642x_bank_info tca642x_regs[] = {
+	{ .input_reg = 0x00,
+	  .output_reg = 0x04,
+	  .polarity_reg = 0x08,
+	  .configuration_reg = 0x0c },
+	{ .input_reg = 0x01,
+	  .output_reg = 0x05,
+	  .polarity_reg = 0x09,
+	  .configuration_reg = 0x0d },
+	{ .input_reg = 0x02,
+	  .output_reg = 0x06,
+	  .polarity_reg = 0x0a,
+	  .configuration_reg = 0x0e },
+};
+
+/*
+ * Modify masked bits in register
+ */
+static int tca642x_reg_write(uchar chip, uint8_t addr,
+		uint8_t reg_bit, uint8_t data)
+{
+	uint8_t valw;
+	int org_bus_num;
+	int ret;
+
+	org_bus_num = i2c_get_bus_num();
+	i2c_set_bus_num(CONFIG_SYS_I2C_TCA642X_BUS_NUM);
+
+	if (i2c_read(chip, addr, 1, (uint8_t *)&valw, 1)) {
+		printf("Could not read before writing\n");
+		ret = -1;
+		goto error;
+	}
+	valw &= ~reg_bit;
+	valw |= data;
+
+	ret = i2c_write(chip, addr, 1, (u8 *)&valw, 1);
+
+error:
+	i2c_set_bus_num(org_bus_num);
+	return ret;
+}
+
+static int tca642x_reg_read(uchar chip, uint8_t addr, uint8_t *data)
+{
+	uint8_t valw;
+	int org_bus_num;
+	int ret = 0;
+
+	org_bus_num = i2c_get_bus_num();
+	i2c_set_bus_num(CONFIG_SYS_I2C_TCA642X_BUS_NUM);
+	if (i2c_read(chip, addr, 1, (u8 *)&valw, 1)) {
+		ret = -1;
+		goto error;
+	}
+
+	*data = valw;
+
+error:
+	i2c_set_bus_num(org_bus_num);
+	return ret;
+}
+
+/*
+ * Set output value of IO pins in 'reg_bit' to corresponding value in 'data'
+ * 0 = low, 1 = high
+ */
+int tca642x_set_val(uchar chip, uint8_t gpio_bank,
+					uint8_t reg_bit, uint8_t data)
+{
+	uint8_t out_reg = tca642x_regs[gpio_bank].output_reg;
+
+	return tca642x_reg_write(chip, out_reg, reg_bit, data);
+}
+
+/*
+ * Set read polarity of IO pins in 'reg_bit' to corresponding value in 'data'
+ * 0 = read pin value, 1 = read inverted pin value
+ */
+int tca642x_set_pol(uchar chip, uint8_t gpio_bank,
+					uint8_t reg_bit, uint8_t data)
+{
+	uint8_t pol_reg = tca642x_regs[gpio_bank].polarity_reg;
+
+	return tca642x_reg_write(chip, pol_reg, reg_bit, data);
+}
+
+/*
+ * Set direction of IO pins in 'reg_bit' to corresponding value in 'data'
+ * 0 = output, 1 = input
+ */
+int tca642x_set_dir(uchar chip, uint8_t gpio_bank,
+					uint8_t reg_bit, uint8_t data)
+{
+	uint8_t config_reg = tca642x_regs[gpio_bank].configuration_reg;
+
+	return tca642x_reg_write(chip, config_reg, reg_bit, data);
+}
+
+/*
+ * Read current logic level of all IO pins
+ */
+int tca642x_get_val(uchar chip, uint8_t gpio_bank)
+{
+	uint8_t val;
+	uint8_t in_reg = tca642x_regs[gpio_bank].input_reg;
+
+	if (tca642x_reg_read(chip, in_reg, &val) < 0)
+		return -1;
+
+	return (int)val;
+}
+
+/*
+ * Set the inital register states for the tca642x gpio expander
+ */
+int tca642x_set_inital_state(uchar chip, struct tca642x_bank_info init_data[])
+{
+	int i, ret;
+	uint8_t config_reg;
+	uint8_t polarity_reg;
+	uint8_t output_reg;
+
+	for (i = 0; i < 3; i++) {
+		config_reg = tca642x_regs[i].configuration_reg;
+		ret = tca642x_reg_write(chip, config_reg, 0xff,
+				init_data[i].configuration_reg);
+		polarity_reg = tca642x_regs[i].polarity_reg;
+		ret = tca642x_reg_write(chip, polarity_reg, 0xff,
+				init_data[i].polarity_reg);
+		output_reg = tca642x_regs[i].output_reg;
+		ret = tca642x_reg_write(chip, output_reg, 0xff,
+				init_data[i].output_reg);
+	}
+
+	return ret;
+}
+
+#ifdef CONFIG_CMD_TCA642X
+/*
+ * Display tca642x information
+ */
+static int tca642x_info(uchar chip)
+{
+	int i, j;
+	uint8_t data;
+
+	printf("tca642x@ 0x%x (%d pins):\n", chip, 24);
+	for (i = 0; i < 3; i++) {
+		printf("Bank %i\n", i);
+		if (tca642x_reg_read(chip,
+				     tca642x_regs[i].configuration_reg,
+				     &data) < 0)
+			return -1;
+		printf("\tConfiguration: ");
+		for (j = 7; j >= 0; j--)
+			printf("%c", data & (1 << j) ? 'i' : 'o');
+		printf("\n");
+
+		if (tca642x_reg_read(chip,
+				     tca642x_regs[i].polarity_reg, &data) < 0)
+			return -1;
+		printf("\tPolarity: ");
+		for (j = 7; j >= 0; j--)
+			printf("%c", data & (1 << j) ? '1' : '0');
+		printf("\n");
+
+		if (tca642x_reg_read(chip,
+				     tca642x_regs[i].input_reg, &data) < 0)
+			return -1;
+		printf("\tInput value: ");
+		for (j = 7; j >= 0; j--)
+			printf("%c", data & (1 << j) ? '1' : '0');
+		printf("\n");
+
+		if (tca642x_reg_read(chip,
+				     tca642x_regs[i].output_reg, &data) < 0)
+			return -1;
+		printf("\tOutput value: ");
+		for (j = 7; j >= 0; j--)
+			printf("%c", data & (1 << j) ? '1' : '0');
+		printf("\n");
+	}
+
+	return 0;
+}
+
+cmd_tbl_t cmd_tca642x[] = {
+	U_BOOT_CMD_MKENT(device, 3, 0, (void *)TCA642X_CMD_DEVICE, "", ""),
+	U_BOOT_CMD_MKENT(output, 4, 0, (void *)TCA642X_CMD_OUTPUT, "", ""),
+	U_BOOT_CMD_MKENT(input, 3, 0, (void *)TCA642X_CMD_INPUT, "", ""),
+	U_BOOT_CMD_MKENT(invert, 4, 0, (void *)TCA642X_CMD_INVERT, "", ""),
+	U_BOOT_CMD_MKENT(info, 2, 0, (void *)TCA642X_CMD_INFO, "", ""),
+};
+
+int do_tca642x(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	static uchar chip = CONFIG_SYS_I2C_TCA642X_ADDR;
+	int ret = CMD_RET_USAGE, val;
+	uint8_t gpio_bank = 0;
+	uint8_t bank_shift;
+	ulong ul_arg2 = 0;
+	ulong ul_arg3 = 0;
+	cmd_tbl_t *c;
+
+	c = find_cmd_tbl(argv[1], cmd_tca642x, ARRAY_SIZE(cmd_tca642x));
+
+	/* All commands but "device" require 'maxargs' arguments */
+	if (!c ||
+	    !((argc == (c->maxargs)) ||
+	    (((int)c->cmd == TCA642X_CMD_DEVICE) &&
+	    (argc == (c->maxargs - 1))))) {
+		return CMD_RET_USAGE;
+	}
+
+	/* arg2 used as chip number or pin number */
+	if (argc > 2)
+		ul_arg2 = simple_strtoul(argv[2], NULL, 10);
+
+	/* arg3 used as pin or invert value */
+	if (argc > 3) {
+		ul_arg3 = simple_strtoul(argv[3], NULL, 10) & 0x1;
+		if (ul_arg2 <= 7) {
+			gpio_bank = 0;
+		} else if ((ul_arg2 >= 10) && (ul_arg2 <= 17)) {
+			gpio_bank = 1;
+		} else if ((ul_arg2 >= 20) && (ul_arg2 <= 27)) {
+			gpio_bank = 2;
+		} else {
+			printf("Requested pin is not available\n");
+			ret = CMD_RET_FAILURE;
+			goto error;
+		}
+	}
+
+	switch ((int)c->cmd) {
+	case TCA642X_CMD_INFO:
+		ret = tca642x_info(chip);
+		if (ret)
+			ret = CMD_RET_FAILURE;
+		break;
+
+	case TCA642X_CMD_DEVICE:
+		if (argc == 3)
+			chip = (uint8_t)ul_arg2;
+		printf("Current device address: 0x%x\n", chip);
+		ret = CMD_RET_SUCCESS;
+		break;
+
+	case TCA642X_CMD_INPUT:
+		bank_shift = ul_arg2 - (gpio_bank * 10);
+		ret = tca642x_set_dir(chip, gpio_bank, (1 << bank_shift),
+				TCA642X_DIR_IN << bank_shift);
+		val = (tca642x_get_val(chip, gpio_bank) &
+				(1 << bank_shift)) != 0;
+
+		if (ret)
+			ret = CMD_RET_FAILURE;
+		else
+			printf("chip 0x%02x, pin 0x%lx = %d\n", chip,
+			       ul_arg2, val);
+		break;
+
+	case TCA642X_CMD_OUTPUT:
+		bank_shift = ul_arg2 - (gpio_bank * 10);
+		ret = tca642x_set_dir(chip, gpio_bank, (1 << bank_shift),
+				(TCA642X_DIR_OUT << bank_shift));
+		if (!ret)
+			ret = tca642x_set_val(chip,
+					      gpio_bank, (1 << bank_shift),
+					      (ul_arg3 << bank_shift));
+		if (ret)
+			ret = CMD_RET_FAILURE;
+		break;
+
+	case TCA642X_CMD_INVERT:
+		bank_shift = ul_arg2 - (gpio_bank * 10);
+		ret = tca642x_set_pol(chip, gpio_bank, (1 << bank_shift),
+					(ul_arg3 << bank_shift));
+		if (ret)
+			ret = CMD_RET_FAILURE;
+		break;
+	}
+error:
+	if (ret == CMD_RET_FAILURE)
+		eprintf("Error talking to chip at 0x%x\n", chip);
+
+	return ret;
+}
+
+U_BOOT_CMD(
+	tca642x,	5,	1,	do_tca642x,
+	"tca642x gpio access",
+	"device [dev]\n"
+	"	- show or set current device address\n"
+	"tca642x info\n"
+	"	- display info for current chip\n"
+	"tca642x output pin 0|1\n"
+	"	- set pin as output and drive low or high\n"
+	"tca642x invert pin 0|1\n"
+	"	- disable/enable polarity inversion for reads\n"
+	"tca642x input pin\n"
+	"	- set pin as input and read value"
+);
+
+#endif /* CONFIG_CMD_TCA642X */