Re: [PATCH v3 03/16] mfd: mfd-core: match device tree node against reg property

Michael Walle
2020-04-29T22:19:03Z

Hi Lee,

Am 2020-04-23 19:45, schrieb Michael Walle:
> There might be multiple children with the device tree compatible, for
> example if a MFD has multiple instances of the same function. In this
> case only the first is matched and the other children get a wrong
> of_node reference.
> Add a new option to match also against the unit address of the child
> node. Additonally, a new helper OF_MFD_CELL_REG is added.

Do you think this is feasible? I guess this is the biggest uncertainty
for me at the moment in this patch series.

-michael

>
> Signed-off-by: Michael Walle <michael@walle.cc>
> ---
> drivers/mfd/mfd-core.c | 29 ++++++++++++++++++++---------
> include/linux/mfd/core.h | 26 ++++++++++++++++++++------
> 2 files changed, 40 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c
> index e735565969b3..4ecb376338f7 100644
> --- a/drivers/mfd/mfd-core.c
> +++ b/drivers/mfd/mfd-core.c
> @@ -117,6 +117,7 @@ static int mfd_add_device(struct device *parent,
> int id,
> struct device_node *np = NULL;
> int ret = -ENOMEM;
> int platform_id;
> + u32 of_reg;
> int r;
>
> if (id == PLATFORM_DEVID_AUTO)
> @@ -151,16 +152,26 @@ static int mfd_add_device(struct device *parent,
> int id,
>
> if (parent->of_node && cell->of_compatible) {
> for_each_child_of_node(parent->of_node, np) {
> - if (of_device_is_compatible(np, cell->of_compatible)) {
> - if (!of_device_is_available(np)) {
> - /* Ignore disabled devices error free */
> - ret = 0;
> - goto fail_alias;
> - }
> - pdev->dev.of_node = np;
> - pdev->dev.fwnode = &np->fwnode;
> - break;
> + if (!of_device_is_compatible(np, cell->of_compatible))
> + continue;
> +
> + /* also match the unit address if set */
> + if (cell->of_reg & MFD_OF_REG_VALID) {
> + if (of_property_read_u32(np, "reg", &of_reg))
> + continue;
> + if ((cell->of_reg & MFD_OF_REG_MASK) != of_reg)
> + continue;
> }
> +
> + if (!of_device_is_available(np)) {
> + /* Ignore disabled devices error free */
> + ret = 0;
> + goto fail_alias;
> + }
> +
> + pdev->dev.of_node = np;
> + pdev->dev.fwnode = &np->fwnode;
> + break;
> }
> }
>
> diff --git a/include/linux/mfd/core.h b/include/linux/mfd/core.h
> index d01d1299e49d..c2c0ad6b14f3 100644
> --- a/include/linux/mfd/core.h
> +++ b/include/linux/mfd/core.h
> @@ -13,8 +13,11 @@
> #include <linux/platform_device.h>
>
> #define MFD_RES_SIZE(arr) (sizeof(arr) / sizeof(struct resource))
> +#define MFD_OF_REG_VALID BIT(31)
> +#define MFD_OF_REG_MASK GENMASK(30, 0)
>
> -#define MFD_CELL_ALL(_name, _res, _pdata, _pdsize, _id, _compat,
> _match)\
> +#define MFD_CELL_ALL(_name, _res, _pdata, _pdsize, _id, _compat, \
> + _of_reg, _match) \
> { \
> .name = (_name), \
> .resources = (_res), \
> @@ -22,24 +25,32 @@
> .platform_data = (_pdata), \
> .pdata_size = (_pdsize), \
> .of_compatible = (_compat), \
> + .of_reg = (_of_reg), \
> .acpi_match = (_match), \
> .id = (_id), \
> }
>
> +#define OF_MFD_CELL_REG(_name, _res, _pdata, _pdsize, _id, _compat, \
> + _of_reg) \
> + MFD_CELL_ALL(_name, _res, _pdata, _pdsize, _id, _compat, \
> + ((_of_reg) | MFD_OF_REG_VALID), NULL) \
> +
> #define OF_MFD_CELL(_name, _res, _pdata, _pdsize,_id, _compat) \
> - MFD_CELL_ALL(_name, _res, _pdata, _pdsize, _id, _compat, NULL) \
> + MFD_CELL_ALL(_name, _res, _pdata, _pdsize, _id, _compat, \
> + 0, NULL) \
>
> #define ACPI_MFD_CELL(_name, _res, _pdata, _pdsize, _id, _match) \
> - MFD_CELL_ALL(_name, _res, _pdata, _pdsize, _id, NULL, _match) \
> + MFD_CELL_ALL(_name, _res, _pdata, _pdsize, _id, NULL, 0, \
> + _match) \
>
> #define MFD_CELL_BASIC(_name, _res, _pdata, _pdsize, _id) \
> - MFD_CELL_ALL(_name, _res, _pdata, _pdsize, _id, NULL, NULL) \
> + MFD_CELL_ALL(_name, _res, _pdata, _pdsize, _id, NULL, 0, NULL) \
>
> #define MFD_CELL_RES(_name, _res) \
> - MFD_CELL_ALL(_name, _res, NULL, 0, 0, NULL, NULL) \
> + MFD_CELL_ALL(_name, _res, NULL, 0, 0, NULL, 0, NULL) \
>
> #define MFD_CELL_NAME(_name) \
> - MFD_CELL_ALL(_name, NULL, NULL, 0, 0, NULL, NULL) \
> + MFD_CELL_ALL(_name, NULL, NULL, 0, 0, NULL, 0, NULL) \
>
> struct irq_domain;
> struct property_entry;
> @@ -78,6 +89,9 @@ struct mfd_cell {
> */
> const char *of_compatible;
>
> + /* matching the reg property if set */
> + unsigned int of_reg;
> +
> /* Matches ACPI */
> const struct mfd_cell_acpi_match *acpi_match;