[U-Boot] [PATCH v3 1/2] gpio: tca642x: Add the tca642x gpio expander driver
Dan Murphy
dmurphy at ti.com
Thu Jul 11 20:10:27 CEST 2013
Add the tca642x gpio expander driver
Datasheet:
http://www.ti.com/product/tca6424a
Signed-off-by: Dan Murphy <dmurphy at ti.com>
---
v2 - Updated per comments - http://patchwork.ozlabs.org/patch/257602/
v3 - Fixed checkpatch issues - http://patchwork.ozlabs.org/patch/257841/
drivers/gpio/Makefile | 1 +
drivers/gpio/tca642x.c | 333 ++++++++++++++++++++++++++++++++++++++++++++++++
include/tca642x.h | 69 ++++++++++
3 files changed, 403 insertions(+)
create mode 100644 drivers/gpio/tca642x.c
create mode 100644 include/tca642x.h
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index f77c1ec..7e74dfe 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -49,6 +49,7 @@ 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 at 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 */
diff --git a/include/tca642x.h b/include/tca642x.h
new file mode 100644
index 0000000..bda86c1
--- /dev/null
+++ b/include/tca642x.h
@@ -0,0 +1,69 @@
+/*
+ * Copyright 2013 Texas Instruments, Inc.
+ * Author: Dan Murphy <dmurphy at 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
+ */
+
+#ifndef __TCA642X_H_
+#define __TCA642X_H_
+
+#ifdef CONFIG_CMD_TCA642X
+enum {
+ TCA642X_CMD_INFO,
+ TCA642X_CMD_DEVICE,
+ TCA642X_CMD_OUTPUT,
+ TCA642X_CMD_INPUT,
+ TCA642X_CMD_INVERT,
+};
+#endif
+
+#define TCA642X_OUT_LOW 0
+#define TCA642X_OUT_HIGH 1
+#define TCA642X_POL_NORMAL 0
+#define TCA642X_POL_INVERT 1
+#define TCA642X_DIR_OUT 0
+#define TCA642X_DIR_IN 1
+
+/* Default to an address that hopefully won't corrupt other i2c devices */
+#ifndef CONFIG_SYS_I2C_TCA642X_ADDR
+#define CONFIG_SYS_I2C_TCA642X_ADDR (~0)
+#endif
+
+/* Default to an address that hopefully won't corrupt other i2c devices */
+#ifndef CONFIG_SYS_I2C_TCA642X_BUS_NUM
+#define CONFIG_SYS_I2C_TCA642X_BUS_NUM (0)
+#endif
+
+struct tca642x_bank_info {
+ uint8_t input_reg;
+ uint8_t output_reg;
+ uint8_t polarity_reg;
+ uint8_t configuration_reg;
+};
+
+int tca642x_set_val(uchar chip, uint8_t gpio_bank,
+ uint8_t reg_bit, uint8_t data);
+int tca642x_set_pol(uchar chip, uint8_t gpio_bank,
+ uint8_t reg_bit, uint8_t data);
+int tca642x_set_dir(uchar chip, uint8_t gpio_bank,
+ uint8_t reg_bit, uint8_t data);
+int tca642x_get_val(uchar chip, uint8_t gpio_bank);
+int tca642x_set_inital_state(uchar chip, struct tca642x_bank_info init_data[]);
+
+#endif /* __TCA642X_H_ */
--
1.7.9.5
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