[U-Boot,[PATCH,v3,1/2] gpio: tca642x: Add the tca642x gpio expander driver

Submitted by Dan Murphy on July 10, 2013, 8:06 p.m.

Details

Message ID 1373486763-13091-1-git-send-email-dmurphy@ti.com
State Superseded
Delegated to: Tom Rini
Headers show

Commit Message

Dan Murphy July 10, 2013, 8:06 p.m.
Add the tca642x gpio expander driver

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

Signed-off-by: Dan Murphy <dmurphy@ti.com>
---
 drivers/gpio/Makefile  |    1 +
 drivers/gpio/tca642x.c |  322 ++++++++++++++++++++++++++++++++++++++++++++++++
 include/tca642x.h      |   66 ++++++++++
 3 files changed, 389 insertions(+)
 create mode 100644 drivers/gpio/tca642x.c
 create mode 100644 include/tca642x.h

Comments

Tom Rini July 11, 2013, 2:31 p.m.
On Wed, Jul 10, 2013 at 03:06:02PM -0500, Dan Murphy wrote:

> Add the tca642x gpio expander driver
> 
> Datasheet:
> http://www.ti.com/product/tca6424a
> 
> Signed-off-by: Dan Murphy <dmurphy@ti.com>
> ---
>  drivers/gpio/Makefile  |    1 +
>  drivers/gpio/tca642x.c |  322 ++++++++++++++++++++++++++++++++++++++++++++++++
>  include/tca642x.h      |   66 ++++++++++
>  3 files changed, 389 insertions(+)
>  create mode 100644 drivers/gpio/tca642x.c
>  create mode 100644 include/tca642x.h

Generally fine, but running checkpatch.pl:
total: 0 errors, 12 warnings, 2 checks, 395 lines checked

NOTE: Ignored message types: COMPLEX_MACRO CONSIDER_KSTRTO MINMAX
MULTISTATEMENT_MACRO_USE_DO_WHILE NETWORKING_BLOCK_COMMENT_STYLE
USLEEP_RANGE

/tmp/gpio1.mbox has style problems, please review.

If any of these errors are false positives, please report
them to the maintainer, see CHECKPATCH in MAINTAINERS.

So, please address those.
Dan Murphy July 11, 2013, 3:11 p.m.
On 07/11/2013 09:31 AM, Tom Rini wrote:
> On Wed, Jul 10, 2013 at 03:06:02PM -0500, Dan Murphy wrote:
>
>> Add the tca642x gpio expander driver
>>
>> Datasheet:
>> http://www.ti.com/product/tca6424a
>>
>> Signed-off-by: Dan Murphy <dmurphy@ti.com>
>> ---
>>  drivers/gpio/Makefile  |    1 +
>>  drivers/gpio/tca642x.c |  322 ++++++++++++++++++++++++++++++++++++++++++++++++
>>  include/tca642x.h      |   66 ++++++++++
>>  3 files changed, 389 insertions(+)
>>  create mode 100644 drivers/gpio/tca642x.c
>>  create mode 100644 include/tca642x.h
> Generally fine, but running checkpatch.pl:
> total: 0 errors, 12 warnings, 2 checks, 395 lines checked
>
> NOTE: Ignored message types: COMPLEX_MACRO CONSIDER_KSTRTO MINMAX
> MULTISTATEMENT_MACRO_USE_DO_WHILE NETWORKING_BLOCK_COMMENT_STYLE
> USLEEP_RANGE
>
> /tmp/gpio1.mbox has style problems, please review.
>
> If any of these errors are false positives, please report
> them to the maintainer, see CHECKPATCH in MAINTAINERS.
>
> So, please address those.
>
Yeah I ran cp on this file and when I looked @ it fixing the LTLs would have made the code look messy IMHO.

But I will fix it anyway and re-submit.

Patch hide | download patch | download mbox

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..a0c7a8b
--- /dev/null
+++ b/drivers/gpio/tca642x.c
@@ -0,0 +1,322 @@ 
+/*
+ * 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 */
diff --git a/include/tca642x.h b/include/tca642x.h
new file mode 100644
index 0000000..64e4338
--- /dev/null
+++ b/include/tca642x.h
@@ -0,0 +1,66 @@ 
+/*
+ * 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
+ */
+
+#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_ */