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Subject[PATCH 3/4] mtd: phram: Allow probing via reserved-memory
Date
Allow phram to be probed from the devicetree.  It expects to be in a
reserved-memory node as documented by the bindings. This allows things
like partitioning to be specified via the devicetree.

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
---
drivers/mtd/devices/phram.c | 67 ++++++++++++++++++++++++++++++++++---
drivers/of/platform.c | 1 +
2 files changed, 64 insertions(+), 4 deletions(-)

diff --git a/drivers/mtd/devices/phram.c b/drivers/mtd/devices/phram.c
index d503821a3e60..6dfe9401a3c5 100644
--- a/drivers/mtd/devices/phram.c
+++ b/drivers/mtd/devices/phram.c
@@ -27,6 +27,9 @@
#include <linux/slab.h>
#include <linux/mtd/mtd.h>
#include <asm/div64.h>
+#include <linux/platform_device.h>
+#include <linux/of_address.h>
+#include <linux/of.h>

struct phram_mtd_list {
struct mtd_info mtd;
@@ -89,8 +92,10 @@ static void unregister_devices(void)
}
}

-static int register_device(char *name, phys_addr_t start, size_t len, uint32_t erasesize)
+static int register_device(struct platform_device *pdev, const char *name,
+ phys_addr_t start, size_t len, uint32_t erasesize)
{
+ struct device_node *np = pdev ? pdev->dev.of_node : NULL;
struct phram_mtd_list *new;
int ret = -ENOMEM;

@@ -119,13 +124,19 @@ static int register_device(char *name, phys_addr_t start, size_t len, uint32_t e
new->mtd.erasesize = erasesize;
new->mtd.writesize = 1;

+ mtd_set_of_node(&new->mtd, np);
+
ret = -EAGAIN;
if (mtd_device_register(&new->mtd, NULL, 0)) {
pr_err("Failed to register new device\n");
goto out2;
}

- list_add_tail(&new->list, &phram_list);
+ if (pdev)
+ platform_set_drvdata(pdev, new);
+ else
+ list_add_tail(&new->list, &phram_list);
+
return 0;

out2:
@@ -278,7 +289,7 @@ static int phram_setup(const char *val)
goto error;
}

- ret = register_device(name, start, len, (uint32_t)erasesize);
+ ret = register_device(NULL, name, start, len, (uint32_t)erasesize);
if (ret)
goto error;

@@ -325,10 +336,54 @@ static int phram_param_call(const char *val, const struct kernel_param *kp)
module_param_call(phram, phram_param_call, NULL, NULL, 0200);
MODULE_PARM_DESC(phram, "Memory region to map. \"phram=<name>,<start>,<length>[,<erasesize>]\"");

+#ifdef CONFIG_OF
+static const struct of_device_id phram_of_match[] = {
+ { .compatible = "phram" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, phram_of_match)
+#endif
+
+static int phram_probe(struct platform_device *pdev)
+{
+ struct resource *res;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ return -ENOMEM;
+
+ /* mtd_set_of_node() reads name from "label" */
+ return register_device(pdev, NULL, res->start, resource_size(res),
+ PAGE_SIZE);
+}
+
+static int phram_remove(struct platform_device *pdev)
+{
+ struct phram_mtd_list *phram = platform_get_drvdata(pdev);
+
+ mtd_device_unregister(&phram->mtd);
+ iounmap(phram->mtd.priv);
+ kfree(phram);
+
+ return 0;
+}
+
+static struct platform_driver phram_driver = {
+ .probe = phram_probe,
+ .remove = phram_remove,
+ .driver = {
+ .name = "phram",
+ .of_match_table = of_match_ptr(phram_of_match),
+ },
+};

static int __init init_phram(void)
{
- int ret = 0;
+ int ret;
+
+ ret = platform_driver_register(&phram_driver);
+ if (ret)
+ return ret;

#ifndef MODULE
if (phram_paramline[0])
@@ -336,12 +391,16 @@ static int __init init_phram(void)
phram_init_called = 1;
#endif

+ if (ret)
+ platform_driver_unregister(&phram_driver);
+
return ret;
}

static void __exit cleanup_phram(void)
{
unregister_devices();
+ platform_driver_unregister(&phram_driver);
}

module_init(init_phram);
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index a16b74f32aa9..55d62b82c650 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -509,6 +509,7 @@ EXPORT_SYMBOL_GPL(of_platform_default_populate);

#ifndef CONFIG_PPC
static const struct of_device_id reserved_mem_matches[] = {
+ { .compatible = "phram" },
{ .compatible = "qcom,rmtfs-mem" },
{ .compatible = "qcom,cmd-db" },
{ .compatible = "qcom,smem" },
--
2.34.1
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