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

From: Michael Walle
Date: Wed Apr 29 2020 - 18:19:01 EST


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@xxxxxxxx>
---
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;