i2c: Implement i2c_get_chip_by_phandle()

This new function enhances the i2c_get_chip*() toolbox by implementing a
variant that does not require a chip_addr. Instead, the desired device
is pointed to by a phandle.

Signed-off-by: Philip Richard Oberfichtner <pro@denx.de>
Reviewed-by: Heiko Schocher <hs@denx.de>
This commit is contained in:
Philip Richard Oberfichtner 2023-10-31 08:38:46 +01:00 committed by Heiko Schocher
parent 31f4ee4b13
commit b483552773
2 changed files with 87 additions and 0 deletions

View File

@ -388,6 +388,81 @@ int i2c_get_chip_for_busnum(int busnum, int chip_addr, uint offset_len,
return 0;
}
/* Find and probe I2C bus based on a chip attached to it */
static int i2c_get_parent_bus(ofnode chip, struct udevice **devp)
{
ofnode node;
struct udevice *dev;
int ret;
node = ofnode_get_parent(chip);
if (!ofnode_valid(node))
return -ENODEV;
ret = uclass_get_device_by_ofnode(UCLASS_I2C, node, &dev);
if (ret) {
*devp = NULL;
return ret;
}
*devp = dev;
return 0;
}
int i2c_get_chip_by_phandle(const struct udevice *parent, const char *prop_name,
struct udevice **devp)
{
ofnode node;
uint phandle;
struct udevice *bus, *chip;
char *dev_name;
int ret;
debug("%s: Searching I2C chip for phandle \"%s\"\n",
__func__, prop_name);
dev_name = strdup(prop_name);
if (!dev_name) {
ret = -ENOMEM;
goto err_exit;
}
ret = dev_read_u32(parent, "i2cbcdev", &phandle);
if (ret)
goto err_exit;
node = ofnode_get_by_phandle(phandle);
if (!ofnode_valid(node)) {
ret = -ENODEV;
goto err_exit;
}
ret = i2c_get_parent_bus(node, &bus);
if (ret)
goto err_exit;
ret = device_bind_driver_to_node(bus, "i2c_generic_chip_drv",
dev_name, node, &chip);
if (ret)
goto err_exit;
ret = device_probe(chip);
if (ret) {
device_unbind(chip);
goto err_exit;
}
debug("%s succeeded\n", __func__);
*devp = chip;
return 0;
err_exit:
free(dev_name);
debug("%s failed, ret = %d\n", __func__, ret);
*devp = NULL;
return ret;
}
int dm_i2c_probe(struct udevice *bus, uint chip_addr, uint chip_flags,
struct udevice **devp)
{

View File

@ -537,6 +537,18 @@ int i2c_get_chip(struct udevice *bus, uint chip_addr, uint offset_len,
int i2c_get_chip_for_busnum(int busnum, int chip_addr, uint offset_len,
struct udevice **devp);
/**
* i2c_get_chip_by_phandle() - get a device to use to access a chip
* based on a phandle property pointing to it
*
* @parent: Parent device containing the phandle pointer
* @name: Name of phandle property in the parent device node
* @devp: Returns pointer to new device or NULL if not found
* Return: 0 on success, -ve on failure
*/
int i2c_get_chip_by_phandle(const struct udevice *parent, const char *prop_name,
struct udevice **devp);
/**
* i2c_chip_of_to_plat() - Decode standard I2C platform data
*