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

[Michael Walle]

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 <mich...@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;