ARM: davinci: step towards removing at24_platform_data

PATCH Superseded Bartosz Golaszewski 1 participant 20 messages Jun 28, 2018 – Jun 29, 2018

Subsystems (8)

Networking Network drivers Documentation Arm (32-bit) +4 more subsystems

lore

Share & tools

lore

Bartosz Golaszewski

author

2018-06-28 14:32 UTC #0 lore raw

v3 cover ARM: davinci: step towards removing at24_platform_data

From: Bartosz Golaszewski <[email protected]>

Since I took over maintainership of the at24 driver I've been working towards removing at24_platform_data in favor for device properties.

DaVinci is the only platform that's still using it - all other users have already been converted.

One of the obstacles in case of DaVinci is removing the setup() callback from the pdata struct, the only user of which are some davinci boards.

Most boards use the EEPROM to store the MAC address. This series adds support for cell lookups to the nvmem framework, registers relevant cells for all users, converts the davinci_emac driver to using them and replaces at24_platform_data with device properties.

The only board that's still using this callback is now mityomapl138. Unfortunately it stores more info in EEPROM than just the MAC address and will require some more work. Unfortunately I don't have access to this board so I can't test any actual solutions on a live hardware.

Tested on a dm365-evm board.

v1 -> v2:
- for backward compatiblity: fall back to using of_get_mac_address() if we can't get an nvmem cell in patch 7
- add patch 15 which removes dead code

v2 -> v3:
- documented new nvmem cell lookup API
- renamed the nvmem cell lookup routines
- in order to completly remove the mac_addr from davinci's soc_info added a patch that moves reading the MAC address from SPI to the emac driver
- removed more dead code

Bartosz Golaszewski (18):
nvmem: add support for cell lookups
Documentation: nvmem: document lookup entries
ARM: davinci: dm365-evm: use nvmem lookup for mac address
ARM: davinci: dm644-evm: use nvmem lookup for mac address
ARM: davinci: dm646x-evm: use nvmem lookup for mac address
ARM: davinci: da830-evm: use nvmem lookup for mac address
ARM: davinci: mityomapl138: add nvmem cells lookup entries
net: davinci_emac: potentially get the MAC address from MTD
ARM: davinci: da850-evm: remove dead MTD code
net: davinci_emac: use nvmem to retrieve the mac address
ARM: davinci: mityomapl138: don't read the MAC address from machine
code
ARM: davinci: dm365-evm: use device properties for at24 eeprom
ARM: davinci: da830-evm: use device properties for at24 eeprom
ARM: davinci: dm644x-evm: use device properties for at24 eeprom
ARM: davinci: dm646x-evm: use device properties for at24 eeprom
ARM: davinci: sffsdr: fix the at24 eeprom device name
ARM: davinci: sffsdr: use device properties for at24 eeprom
ARM: davinci: remove dead code related to MAC address reading

 Documentation/nvmem/nvmem.txt              | 28 ++++++++
 arch/arm/mach-davinci/board-da830-evm.c    | 25 +++++---
 arch/arm/mach-davinci/board-da850-evm.c    | 28 --------
 arch/arm/mach-davinci/board-dm365-evm.c    | 25 +++++---
 arch/arm/mach-davinci/board-dm644x-evm.c   | 24 ++++---
 arch/arm/mach-davinci/board-dm646x-evm.c   | 25 +++++---
 arch/arm/mach-davinci/board-mityomapl138.c | 30 ++++++---
 arch/arm/mach-davinci/board-sffsdr.c       | 13 ++--
 arch/arm/mach-davinci/common.c             | 15 -----
 drivers/net/ethernet/ti/davinci_emac.c     | 50 ++++++++++++---
 drivers/nvmem/core.c                       | 75 +++++++++++++++++++++-
 include/linux/davinci_emac.h               |  2 -
 include/linux/nvmem-consumer.h             |  6 ++
 include/linux/nvmem-provider.h             | 10 +++
 14 files changed, 253 insertions(+), 103 deletions(-)

Signature · 1 line

2.17.1

Bartosz Golaszewski

author

2018-06-28 14:32 UTC #1 lore raw

PATCH v3 1/18 nvmem: add support for cell lookups

From: Bartosz Golaszewski <[email protected]>

We can currently only register nvmem cells from device tree or by manually calling nvmem_add_cells(). The latter options however forces users to make sure that the nvmem provider with which the cells are associated is registered before the call.

This patch proposes a new solution inspired by other frameworks that offer resource lookups (GPIO, PWM etc.). It adds functions that allow machine code to register nvmem lookup which are later lazily used to add corresponding nvmem cells and remove them if no longer needed.

Signed-off-by Bartosz Golaszewski <[email protected]>

---
 drivers/nvmem/core.c           | 75 +++++++++++++++++++++++++++++++++-
 include/linux/nvmem-consumer.h |  6 +++
 include/linux/nvmem-provider.h | 10 +++++
 3 files changed, 90 insertions(+), 1 deletion(-)

drivers/nvmem/core.c +74 -1

index b5b0cdc21d01..c4889a4b26cf 100644
@@ -62,6 +62,9 @@ static DEFINE_IDA(nvmem_ida);
 static LIST_HEAD(nvmem_cells);
 static DEFINE_MUTEX(nvmem_cells_mutex);
 
+static LIST_HEAD(nvmem_cell_lookups);
+static DEFINE_MUTEX(nvmem_lookup_mutex);
+
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 static struct lock_class_key eeprom_lock_key;
 #endif

@@ -247,6 +250,41 @@ static const struct attribute_group *nvmem_ro_root_dev_groups[] = {
 	NULL,
 };
 
+/**
+ * nvmem_add_lookup_table() - register a number of nvmem cell lookup entries
+ *
+ * @lookup: array of nvmem cell lookup entries
+ * @nentries: number of lookup entries in the array
+ */
+void nvmem_add_lookup_table(struct nvmem_cell_lookup *lookup, size_t nentries)
+{
+	int i;
+
+	mutex_lock(&nvmem_lookup_mutex);
+	for (i = 0; i < nentries; i++)
+		list_add_tail(&lookup[i].list, &nvmem_cell_lookups);
+	mutex_unlock(&nvmem_lookup_mutex);
+}
+EXPORT_SYMBOL_GPL(nvmem_add_lookup_table);
+
+/**
+ * nvmem_del_lookup_table() - unregister a set of previously added nvmem cell
+ *                            lookup entries
+ *
+ * @lookup: array of nvmem cell lookup entries
+ * @nentries: number of lookup entries in the array
+ */
+void nvmem_del_lookup_table(struct nvmem_cell_lookup *lookup, size_t nentries)
+{
+	int i;
+
+	mutex_lock(&nvmem_lookup_mutex);
+	for (i = 0; i < nentries; i++)
+		list_del(&lookup[i].list);
+	mutex_unlock(&nvmem_lookup_mutex);
+}
+EXPORT_SYMBOL_GPL(nvmem_del_lookup_table);
+
 static void nvmem_release(struct device *dev)
 {
 	struct nvmem_device *nvmem = to_nvmem_device(dev);

@@ -916,6 +954,37 @@ struct nvmem_cell *of_nvmem_cell_get(struct device_node *np,
 EXPORT_SYMBOL_GPL(of_nvmem_cell_get);
 #endif
 
+static struct nvmem_cell *nvmem_cell_from_lookup(const char *cell_id)
+{
+	struct nvmem_cell *cell = ERR_PTR(-EPROBE_DEFER);
+	struct nvmem_cell_lookup *lookup;
+	struct nvmem_device *nvmem;
+	int rc;
+
+	mutex_lock(&nvmem_lookup_mutex);
+
+	list_for_each_entry(lookup, &nvmem_cell_lookups, list) {
+		if (strcmp(cell_id, lookup->info.name) == 0) {
+			nvmem = nvmem_find(lookup->nvmem_name);
+			if (!nvmem)
+				goto out;
+
+			rc = nvmem_add_cells(nvmem, &lookup->info, 1);
+			if (rc) {
+				cell = ERR_PTR(rc);
+				goto out;
+			}
+
+			cell = nvmem_cell_get_from_list(cell_id);
+			break;
+		}
+	}
+
+out:
+	mutex_unlock(&nvmem_lookup_mutex);
+	return cell;
+}
+
 /**
  * nvmem_cell_get() - Get nvmem cell of device form a given cell name
  *

@@ -936,7 +1005,11 @@ struct nvmem_cell *nvmem_cell_get(struct device *dev, const char *cell_id)
 			return cell;
 	}
 
-	return nvmem_cell_get_from_list(cell_id);
+	cell = nvmem_cell_get_from_list(cell_id);
+	if (!IS_ERR(cell) || PTR_ERR(cell) == -EPROBE_DEFER)
+		return cell;
+
+	return nvmem_cell_from_lookup(cell_id);
 }
 EXPORT_SYMBOL_GPL(nvmem_cell_get);

include/linux/nvmem-consumer.h +6 -0

index 4e85447f7860..f4b5d3186e94 100644
@@ -29,6 +29,12 @@ struct nvmem_cell_info {
 	unsigned int		nbits;
 };
 
+struct nvmem_cell_lookup {
+	struct nvmem_cell_info	info;
+	struct list_head	list;
+	const char		*nvmem_name;
+};
+
 #if IS_ENABLED(CONFIG_NVMEM)
 
 /* Cell based interface */

include/linux/nvmem-provider.h +10 -0

index 24def6ad09bb..6a17d722062b 100644
@@ -17,6 +17,7 @@
 
 struct nvmem_device;
 struct nvmem_cell_info;
+struct nvmem_cell_lookup;
 typedef int (*nvmem_reg_read_t)(void *priv, unsigned int offset,
 				void *val, size_t bytes);
 typedef int (*nvmem_reg_write_t)(void *priv, unsigned int offset,

@@ -72,6 +73,9 @@ struct nvmem_config {
 struct nvmem_device *nvmem_register(const struct nvmem_config *cfg);
 int nvmem_unregister(struct nvmem_device *nvmem);
 
+void nvmem_add_lookup_table(struct nvmem_cell_lookup *lookup, size_t nentries);
+void nvmem_del_lookup_table(struct nvmem_cell_lookup *lookup, size_t nentries);
+
 struct nvmem_device *devm_nvmem_register(struct device *dev,
 					 const struct nvmem_config *cfg);

@@ -92,6 +96,12 @@ static inline int nvmem_unregister(struct nvmem_device *nvmem)
 	return -ENOSYS;
 }
 
+static inline void
+nvmem_add_lookup_table(struct nvmem_cell_lookup *lookup, size_t nentries) {}
+
+static inline void
+nvmem_del_lookup_table(struct nvmem_cell_lookup *lookup, size_t nentries) {}
+
 static inline struct nvmem_device *
 devm_nvmem_register(struct device *dev, const struct nvmem_config *c)
 {

Signature · 1 line

2.17.1

Bartosz Golaszewski

author

2018-06-28 14:32 UTC #2 lore raw

PATCH v3 2/18 Documentation: nvmem: document lookup entries