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pca953x: support 16-pin devices

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This adds support for for the PCA9535/PCA9539 family of gpio devices which
have 16 output pins.

To let the driver know which devices are 16-pin it is necessary to define
CONFIG_SYS_I2C_PCA953X_WIDTH in your board config file. This is used to
create an array of {chip, ngpio} tuples that are used to determine the
width of a particular chip. For backwards compatibility it is assumed that
any chip not defined in CONFIG_SYS_I2C_PCA953X_WIDTH has 8 pins.

Acked-by: Peter Tyser <ptyser@xes-inc.com>
Tested-by: Peter Tyser <ptyser@xes-inc.com>
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
This commit is contained in:
Chris Packham 2010-12-19 10:12:13 +00:00 committed by Heiko Schocher
parent 89c95f0cd3
commit 5dec49ca22
2 changed files with 94 additions and 22 deletions
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4
README
View File

@ -746,6 +746,10 @@ The following options need to be configured:
CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
CONFIG_PCA953X_INFO - enable pca953x info command
The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
chip-ngpio pairs that tell the PCA953X driver the number of
pins supported by a particular chip.
Note that if the GPIO device uses I2C, then the I2C interface
must also be configured. See I2C Support, below.

112
drivers/gpio/pca953x.c
View File

@ -17,8 +17,8 @@
*/
/*
* Driver for NXP's 4 and 8 bit I2C gpio expanders (eg pca9537, pca9557, etc)
* TODO: support additional devices with more than 8-bits GPIO
* Driver for NXP's 4, 8 and 16 bit I2C gpio expanders (eg pca9537, pca9557,
* pca9539, etc)
*/
#include <common.h>
@ -38,20 +38,81 @@ enum {
PCA953X_CMD_INVERT,
};
#ifdef CONFIG_SYS_I2C_PCA953X_WIDTH
struct pca953x_chip_ngpio {
uint8_t chip;
uint8_t ngpio;
};
static struct pca953x_chip_ngpio pca953x_chip_ngpios[] =
CONFIG_SYS_I2C_PCA953X_WIDTH;
#define NUM_CHIP_GPIOS (sizeof(pca953x_chip_ngpios) / \
sizeof(struct pca953x_chip_ngpio))
/*
* Determine the number of GPIO pins supported. If we don't know we assume
* 8 pins.
*/
static int pca953x_ngpio(uint8_t chip)
{
int i;
for (i = 0; i < NUM_CHIP_GPIOS; i++)
if (pca953x_chip_ngpios[i].chip == chip)
return pca953x_chip_ngpios[i].ngpio;
return 8;
}
#else
static int pca953x_ngpio(uint8_t chip)
{
return 8;
}
#endif
/*
* Modify masked bits in register
*/
static int pca953x_reg_write(uint8_t chip, uint addr, uint mask, uint data)
{
uint8_t val;
uint8_t valb;
uint16_t valw;
if (i2c_read(chip, addr, 1, &val, 1))
return -1;
if (pca953x_ngpio(chip) <= 8) {
if (i2c_read(chip, addr, 1, &valb, 1))
return -1;
val &= ~mask;
val |= data;
valb &= ~mask;
valb |= data;
return i2c_write(chip, addr, 1, &val, 1);
return i2c_write(chip, addr, 1, &valb, 1);
} else {
if (i2c_read(chip, addr << 1, 1, (u8*)&valw, 2))
return -1;
valw &= ~mask;
valw |= data;
return i2c_write(chip, addr << 1, 1, (u8*)&valw, 2);
}
}
static int pca953x_reg_read(uint8_t chip, uint addr, uint *data)
{
uint8_t valb;
uint16_t valw;
if (pca953x_ngpio(chip) <= 8) {
if (i2c_read(chip, addr, 1, &valb, 1))
return -1;
*data = (int)valb;
} else {
if (i2c_read(chip, addr << 1, 1, (u8*)&valw, 2))
return -1;
*data = (int)valw;
}
return 0;
}
/*
@ -86,9 +147,9 @@ int pca953x_set_dir(uint8_t chip, uint mask, uint data)
*/
int pca953x_get_val(uint8_t chip)
{
uint8_t val;
uint val;
if (i2c_read(chip, 0, 1, &val, 1))
if (pca953x_reg_read(chip, PCA953X_IN, &val) < 0)
return -1;
return (int)val;
@ -102,37 +163,44 @@ int pca953x_get_val(uint8_t chip)
static int pca953x_info(uint8_t chip)
{
int i;
uint8_t data;
uint data;
int nr_gpio = pca953x_ngpio(chip);
int msb = nr_gpio - 1;
printf("pca953x@ 0x%x:\n\n", chip);
printf("gpio pins: 76543210\n");
printf("-------------------\n");
printf("pca953x@ 0x%x (%d pins):\n\n", chip, nr_gpio);
printf("gpio pins: ");
for (i = msb; i >= 0; i--)
printf("%x", i);
printf("\n");
for (i = 11 + nr_gpio; i > 0; i--)
printf("-");
printf("\n");
if (i2c_read(chip, PCA953X_CONF, 1, &data, 1))
if (pca953x_reg_read(chip, PCA953X_CONF, &data) < 0)
return -1;
printf("conf: ");
for (i = 7; i >= 0; i--)
for (i = msb; i >= 0; i--)
printf("%c", data & (1 << i) ? 'i' : 'o');
printf("\n");
if (i2c_read(chip, PCA953X_POL, 1, &data, 1))
if (pca953x_reg_read(chip, PCA953X_POL, &data) < 0)
return -1;
printf("invert: ");
for (i = 7; i >= 0; i--)
for (i = msb; i >= 0; i--)
printf("%c", data & (1 << i) ? '1' : '0');
printf("\n");
if (i2c_read(chip, PCA953X_IN, 1, &data, 1))
if (pca953x_reg_read(chip, PCA953X_IN, &data) < 0)
return -1;
printf("input: ");
for (i = 7; i >= 0; i--)
for (i = msb; i >= 0; i--)
printf("%c", data & (1 << i) ? '1' : '0');
printf("\n");
if (i2c_read(chip, PCA953X_OUT, 1, &data, 1))
if (pca953x_reg_read(chip, PCA953X_OUT, &data) < 0)
return -1;
printf("output: ");
for (i = 7; i >= 0; i--)
for (i = msb; i >= 0; i--)
printf("%c", data & (1 << i) ? '1' : '0');
printf("\n");