Commit 7090d2f1 authored by Vincent Whitchurch's avatar Vincent Whitchurch Committed by Miquel Raynal
Browse files

mtd: phram: Allow probing via reserved-memory 



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: default avatarVincent Whitchurch <vincent.whitchurch@axis.com>
Acked-by: default avatarRob Herring <robh@kernel.org>
Signed-off-by: default avatarMiquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220412135302.1682890-4-vincent.whitchurch@axis.com
parent 4e969459

drivers/mtd/devices/phram.c

+63 −4
Original line number Diff line number Diff line
@@ -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;

	}



	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);

drivers/of/platform.c

+1 −0
Original line number Diff line number Diff line
@@ -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" },