i2c: pcf8575: Add support for 8 bit I2C IO expanders (like pca8574)
This patch add support for using NXP's pca8574 I2C IO expander, which
has only 8 IO lines.
After this change the .data member's information from struct udevice_id
are used to either sent one or two bytes.
Moreover, the '_le16' suffix from pcf8575_i2c_{write|read}_le16()
functions have been removed as now we also sent 8 bit data.
Signed-off-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Heiko Schocher <hs@denx.de>
diff --git a/drivers/gpio/pcf8575_gpio.c b/drivers/gpio/pcf8575_gpio.c
index bae9695..d5930d9 100644
--- a/drivers/gpio/pcf8575_gpio.c
+++ b/drivers/gpio/pcf8575_gpio.c
@@ -12,15 +12,9 @@
*
* Copyright (C) 2007 David Brownell
*
- */
-
-/*
- * NOTE: The driver and devicetree bindings are borrowed from Linux
- * Kernel, but driver does not support all PCF857x devices. It currently
- * supports PCF8575 16-bit expander by TI and NXP.
+ * Add support for 8 bit expanders - like pca8574
+ * Copyright (C) 2021 Lukasz Majewski - DENX Software Engineering
*
- * TODO(vigneshr@ti.com):
- * Support 8 bit PCF857x compatible expanders.
*/
#include <common.h>
@@ -49,15 +43,15 @@
unsigned int out; /* software latch */
};
-/* Read/Write to 16-bit I/O expander */
+/* Read/Write to I/O expander */
-static int pcf8575_i2c_write_le16(struct udevice *dev, unsigned int word)
+static int pcf8575_i2c_write(struct udevice *dev, unsigned int word)
{
struct dm_i2c_chip *chip = dev_get_parent_plat(dev);
u8 buf[2] = { word & 0xff, word >> 8, };
int ret;
- ret = dm_i2c_write(dev, 0, buf, 2);
+ ret = dm_i2c_write(dev, 0, buf, dev_get_driver_data(dev));
if (ret)
printf("%s i2c write failed to addr %x\n", __func__,
chip->chip_addr);
@@ -65,13 +59,13 @@
return ret;
}
-static int pcf8575_i2c_read_le16(struct udevice *dev)
+static int pcf8575_i2c_read(struct udevice *dev)
{
struct dm_i2c_chip *chip = dev_get_parent_plat(dev);
- u8 buf[2];
+ u8 buf[2] = {0x00, 0x00};
int ret;
- ret = dm_i2c_read(dev, 0, buf, 2);
+ ret = dm_i2c_read(dev, 0, buf, dev_get_driver_data(dev));
if (ret) {
printf("%s i2c read failed from addr %x\n", __func__,
chip->chip_addr);
@@ -87,7 +81,7 @@
int status;
plat->out |= BIT(offset);
- status = pcf8575_i2c_write_le16(dev, plat->out);
+ status = pcf8575_i2c_write(dev, plat->out);
return status;
}
@@ -103,7 +97,7 @@
else
plat->out &= ~BIT(offset);
- ret = pcf8575_i2c_write_le16(dev, plat->out);
+ ret = pcf8575_i2c_write(dev, plat->out);
return ret;
}
@@ -112,7 +106,7 @@
{
int value;
- value = pcf8575_i2c_read_le16(dev);
+ value = pcf8575_i2c_read(dev);
return (value < 0) ? value : ((value & BIT(offset)) >> offset);
}
@@ -130,8 +124,11 @@
int n_latch;
- uc_priv->gpio_count = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev),
- "gpio-count", 16);
+ /*
+ * Number of pins depends on the expander device and is specified
+ * in the struct udevice_id (as in the Linue kernel).
+ */
+ uc_priv->gpio_count = dev_get_driver_data(dev) * 8;
uc_priv->bank_name = fdt_getprop(gd->fdt_blob, dev_of_offset(dev),
"gpio-bank-name", NULL);
if (!uc_priv->bank_name)
@@ -163,8 +160,9 @@
};
static const struct udevice_id pcf8575_gpio_ids[] = {
- { .compatible = "nxp,pcf8575" },
- { .compatible = "ti,pcf8575" },
+ { .compatible = "nxp,pcf8575", .data = 2 },
+ { .compatible = "ti,pcf8575", .data = 2 },
+ { .compatible = "nxp,pca8574", .data = 1 },
{ }
};