[PATCH v6 01/10] mtd: physmap_of: Release resources on error

[PATCH v6 01/10] mtd: physmap_of: Release resources on error

[Ricardo Ribalda Delgado]

During probe, if there was an error the memory region and the memory
map were not properly released.

This can lead a system unusable if deferred probe is in use.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
---
 drivers/mtd/maps/physmap_of_core.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/mtd/maps/physmap_of_core.c b/drivers/mtd/maps/physmap_of_core.c
index 4129535b8e46..062add8b3a6e 100644
--- a/drivers/mtd/maps/physmap_of_core.c
+++ b/drivers/mtd/maps/physmap_of_core.c
@@ -241,10 +241,10 @@ static int of_flash_probe(struct platform_device *dev)
 
 		err = of_flash_probe_gemini(dev, dp, &info->list[i].map);
 		if (err)
-			goto err_out;
+			goto err_out_release;
 		err = of_flash_probe_versatile(dev, dp, &info->list[i].map);
 		if (err)
-			goto err_out;
+			goto err_out_release;
 
 		err = -ENOMEM;
 		info->list[i].map.virt = ioremap(info->list[i].map.phys,
@@ -252,7 +252,7 @@ static int of_flash_probe(struct platform_device *dev)
 		if (!info->list[i].map.virt) {
 			dev_err(&dev->dev, "Failed to ioremap() flash"
 				" region\n");
-			goto err_out;
+			goto err_out_release;
 		}
 
 		simple_map_init(&info->list[i].map);
@@ -290,7 +290,7 @@ static int of_flash_probe(struct platform_device *dev)
 		err = -ENXIO;
 		if (!info->list[i].mtd) {
 			dev_err(&dev->dev, "do_map_probe() failed\n");
-			goto err_out;
+			goto err_out_iounmap;
 		} else {
 			info->list_size++;
 		}
@@ -329,6 +329,10 @@ static int of_flash_probe(struct platform_device *dev)
 
 	return 0;
 
+err_out_iounmap:
+	iounmap(info->list[i].map.virt);
+err_out_release:
+	release_mem_region(res.start, resource_size(&res));
 err_out:
 	kfree(mtd_list);
 err_flash_remove:
-- 
2.19.0

[PATCH v6 02/10] mtd: physmap_of: Remove unused struct of_device_id

[Ricardo Ribalda Delgado]

This struct does not seem to be used anywhere on the code

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
---
 drivers/mtd/maps/physmap_of_gemini.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/drivers/mtd/maps/physmap_of_gemini.c b/drivers/mtd/maps/physmap_of_gemini.c
index 830b1b7e702b..9df62ca721d5 100644
--- a/drivers/mtd/maps/physmap_of_gemini.c
+++ b/drivers/mtd/maps/physmap_of_gemini.c
@@ -44,11 +44,6 @@
 
 #define FLASH_PARALLEL_HIGH_PIN_CNT	(1 << 20)	/* else low pin cnt */
 
-static const struct of_device_id syscon_match[] = {
-	{ .compatible = "cortina,gemini-syscon" },
-	{ },
-};
-
 int of_flash_probe_gemini(struct platform_device *pdev,
 			  struct device_node *np,
 			  struct map_info *map)
-- 
2.19.0

[PATCH v6 03/10] mtd: maps: gpio-addr-flash: Replace custom printk

[Ricardo Ribalda Delgado]

Use preferred print methods dev_*

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
---
 drivers/mtd/maps/gpio-addr-flash.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/mtd/maps/gpio-addr-flash.c b/drivers/mtd/maps/gpio-addr-flash.c
index 9d9723693217..17be47f72973 100644
--- a/drivers/mtd/maps/gpio-addr-flash.c
+++ b/drivers/mtd/maps/gpio-addr-flash.c
@@ -25,11 +25,7 @@
 #include <linux/slab.h>
 #include <linux/types.h>
 
-#define pr_devinit(fmt, args...) \
-	({ static const char __fmt[] = fmt; printk(__fmt, ## args); })
-
 #define DRIVER_NAME "gpio-addr-flash"
-#define PFX DRIVER_NAME ": "
 
 /**
  * struct async_state - keep GPIO flash state
@@ -250,7 +246,7 @@ static int gpio_flash_probe(struct platform_device *pdev)
 	i = 0;
 	do {
 		if (gpio_request(state->gpio_addrs[i], DRIVER_NAME)) {
-			pr_devinit(KERN_ERR PFX "failed to request gpio %d\n",
+			dev_err(&pdev->dev, "failed to request gpio %d\n",
 				state->gpio_addrs[i]);
 			while (i--)
 				gpio_free(state->gpio_addrs[i]);
@@ -260,8 +256,8 @@ static int gpio_flash_probe(struct platform_device *pdev)
 		gpio_direction_output(state->gpio_addrs[i], 0);
 	} while (++i < state->gpio_count);
 
-	pr_devinit(KERN_NOTICE PFX "probing %d-bit flash bus\n",
-		state->map.bankwidth * 8);
+	dev_notice(&pdev->dev, "probing %d-bit flash bus\n",
+		   state->map.bankwidth * 8);
 	state->mtd = do_map_probe(memory->name, &state->map);
 	if (!state->mtd) {
 		for (i = 0; i < state->gpio_count; ++i)
-- 
2.19.0

[PATCH v6 04/10] mtd: maps: gpio-addr-flash: Fix ioremapped size

[Ricardo Ribalda Delgado]

We should only iomap the area of the chip that is memory mapped.
Otherwise we could be mapping devices beyond the memory space or that
belong to other devices.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Fixes: ebd71e3a4861 ("mtd: maps: gpio-addr-flash: fix warnings and make more portable")
Cc: <stable@vger.kernel.org>
---
 drivers/mtd/maps/gpio-addr-flash.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mtd/maps/gpio-addr-flash.c b/drivers/mtd/maps/gpio-addr-flash.c
index 17be47f72973..6de16e81994c 100644
--- a/drivers/mtd/maps/gpio-addr-flash.c
+++ b/drivers/mtd/maps/gpio-addr-flash.c
@@ -234,7 +234,7 @@ static int gpio_flash_probe(struct platform_device *pdev)
 	state->map.copy_to    = gf_copy_to;
 	state->map.bankwidth  = pdata->width;
 	state->map.size       = state->win_size * (1 << state->gpio_count);
-	state->map.virt       = ioremap_nocache(memory->start, state->map.size);
+	state->map.virt       = ioremap_nocache(memory->start, state->win_size);
 	if (!state->map.virt)
 		return -ENOMEM;
 
-- 
2.19.0

[PATCH v6 05/10] mtd: maps: gpio-addr-flash: Use devm_* functions

[Ricardo Ribalda Delgado]

By using devm functions we can make the code cleaner.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
---
 drivers/mtd/maps/gpio-addr-flash.c | 26 ++++++++------------------
 1 file changed, 8 insertions(+), 18 deletions(-)

diff --git a/drivers/mtd/maps/gpio-addr-flash.c b/drivers/mtd/maps/gpio-addr-flash.c
index 6de16e81994c..84404dcc7824 100644
--- a/drivers/mtd/maps/gpio-addr-flash.c
+++ b/drivers/mtd/maps/gpio-addr-flash.c
@@ -213,7 +213,7 @@ static int gpio_flash_probe(struct platform_device *pdev)
 		return -EINVAL;
 
 	arr_size = sizeof(int) * gpios->end;
-	state = kzalloc(sizeof(*state) + arr_size, GFP_KERNEL);
+	state = devm_kzalloc(&pdev->dev, sizeof(*state) + arr_size, GFP_KERNEL);
 	if (!state)
 		return -ENOMEM;
 
@@ -234,9 +234,9 @@ static int gpio_flash_probe(struct platform_device *pdev)
 	state->map.copy_to    = gf_copy_to;
 	state->map.bankwidth  = pdata->width;
 	state->map.size       = state->win_size * (1 << state->gpio_count);
-	state->map.virt       = ioremap_nocache(memory->start, state->win_size);
-	if (!state->map.virt)
-		return -ENOMEM;
+	state->map.virt	      = devm_ioremap_resource(&pdev->dev, memory);
+	if (IS_ERR(state->map.virt))
+		return PTR_ERR(state->map.virt);
 
 	state->map.phys       = NO_XIP;
 	state->map.map_priv_1 = (unsigned long)state;
@@ -245,12 +245,10 @@ static int gpio_flash_probe(struct platform_device *pdev)
 
 	i = 0;
 	do {
-		if (gpio_request(state->gpio_addrs[i], DRIVER_NAME)) {
+		if (devm_gpio_request(&pdev->dev, state->gpio_addrs[i],
+				      DRIVER_NAME)) {
 			dev_err(&pdev->dev, "failed to request gpio %d\n",
 				state->gpio_addrs[i]);
-			while (i--)
-				gpio_free(state->gpio_addrs[i]);
-			kfree(state);
 			return -EBUSY;
 		}
 		gpio_direction_output(state->gpio_addrs[i], 0);
@@ -259,12 +257,8 @@ static int gpio_flash_probe(struct platform_device *pdev)
 	dev_notice(&pdev->dev, "probing %d-bit flash bus\n",
 		   state->map.bankwidth * 8);
 	state->mtd = do_map_probe(memory->name, &state->map);
-	if (!state->mtd) {
-		for (i = 0; i < state->gpio_count; ++i)
-			gpio_free(state->gpio_addrs[i]);
-		kfree(state);
+	if (!state->mtd)
 		return -ENXIO;
-	}
 	state->mtd->dev.parent = &pdev->dev;
 
 	mtd_device_parse_register(state->mtd, part_probe_types, NULL,
@@ -276,13 +270,9 @@ static int gpio_flash_probe(struct platform_device *pdev)
 static int gpio_flash_remove(struct platform_device *pdev)
 {
 	struct async_state *state = platform_get_drvdata(pdev);
-	size_t i = 0;
-	do {
-		gpio_free(state->gpio_addrs[i]);
-	} while (++i < state->gpio_count);
+
 	mtd_device_unregister(state->mtd);
 	map_destroy(state->mtd);
-	kfree(state);
 	return 0;
 }
 
-- 
2.19.0

[PATCH v6 06/10] mtd: maps: gpio-addr-flash: Use order insted of size

[Ricardo Ribalda Delgado]

By using the order of the window instead of the size, we can replace a
lot of expensive division and modulus on the code with simple bit
operations.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
---
 drivers/mtd/maps/gpio-addr-flash.c | 39 ++++++++++++++++--------------
 1 file changed, 21 insertions(+), 18 deletions(-)

diff --git a/drivers/mtd/maps/gpio-addr-flash.c b/drivers/mtd/maps/gpio-addr-flash.c
index 84404dcc7824..89cc8cce161b 100644
--- a/drivers/mtd/maps/gpio-addr-flash.c
+++ b/drivers/mtd/maps/gpio-addr-flash.c
@@ -25,6 +25,8 @@
 #include <linux/slab.h>
 #include <linux/types.h>
 
+#define win_mask(x) ((BIT(x)) - 1)
+
 #define DRIVER_NAME "gpio-addr-flash"
 
 /**
@@ -34,7 +36,7 @@
  *	@gpio_count:  number of GPIOs used to address
  *	@gpio_addrs:  array of GPIOs to twiddle
  *	@gpio_values: cached GPIO values
- *	@win_size:    dedicated memory size (if no GPIOs)
+ *	@win_order:   dedicated memory size (if no GPIOs)
  */
 struct async_state {
 	struct mtd_info *mtd;
@@ -42,7 +44,7 @@ struct async_state {
 	size_t gpio_count;
 	unsigned *gpio_addrs;
 	int *gpio_values;
-	unsigned long win_size;
+	unsigned int win_order;
 };
 #define gf_map_info_to_state(mi) ((struct async_state *)(mi)->map_priv_1)
 
@@ -60,7 +62,8 @@ static void gf_set_gpios(struct async_state *state, unsigned long ofs)
 {
 	size_t i = 0;
 	int value;
-	ofs /= state->win_size;
+
+	ofs >>= state->win_order;
 	do {
 		value = ofs & (1 << i);
 		if (state->gpio_values[i] != value) {
@@ -83,7 +86,7 @@ static map_word gf_read(struct map_info *map, unsigned long ofs)
 
 	gf_set_gpios(state, ofs);
 
-	word = readw(map->virt + (ofs % state->win_size));
+	word = readw(map->virt + (ofs & win_mask(state->win_order)));
 	test.x[0] = word;
 	return test;
 }
@@ -105,14 +108,14 @@ static void gf_copy_from(struct map_info *map, void *to, unsigned long from, ssi
 	int this_len;
 
 	while (len) {
-		if ((from % state->win_size) + len > state->win_size)
-			this_len = state->win_size - (from % state->win_size);
-		else
-			this_len = len;
+		this_len = from & win_mask(state->win_order);
+		this_len = BIT(state->win_order) - this_len;
+		this_len = min_t(int, len, this_len);
 
 		gf_set_gpios(state, from);
-		memcpy_fromio(to, map->virt + (from % state->win_size),
-			 this_len);
+		memcpy_fromio(to,
+			      map->virt + (from & win_mask(state->win_order)),
+			      this_len);
 		len -= this_len;
 		from += this_len;
 		to += this_len;
@@ -132,7 +135,7 @@ static void gf_write(struct map_info *map, map_word d1, unsigned long ofs)
 	gf_set_gpios(state, ofs);
 
 	d = d1.x[0];
-	writew(d, map->virt + (ofs % state->win_size));
+	writew(d, map->virt + (ofs & win_mask(state->win_order)));
 }
 
 /**
@@ -152,13 +155,13 @@ static void gf_copy_to(struct map_info *map, unsigned long to,
 	int this_len;
 
 	while (len) {
-		if ((to % state->win_size) + len > state->win_size)
-			this_len = state->win_size - (to % state->win_size);
-		else
-			this_len = len;
+		this_len = to & win_mask(state->win_order);
+		this_len = BIT(state->win_order) - this_len;
+		this_len = min_t(int, len, this_len);
 
 		gf_set_gpios(state, to);
-		memcpy_toio(map->virt + (to % state->win_size), from, len);
+		memcpy_toio(map->virt + (to & win_mask(state->win_order)),
+			    from, len);
 
 		len -= this_len;
 		to += this_len;
@@ -224,7 +227,7 @@ static int gpio_flash_probe(struct platform_device *pdev)
 	state->gpio_count     = gpios->end;
 	state->gpio_addrs     = (void *)(unsigned long)gpios->start;
 	state->gpio_values    = (void *)(state + 1);
-	state->win_size       = resource_size(memory);
+	state->win_order      = get_bitmask_order(resource_size(memory)) - 1;
 	memset(state->gpio_values, 0xff, arr_size);
 
 	state->map.name       = DRIVER_NAME;
@@ -233,7 +236,7 @@ static int gpio_flash_probe(struct platform_device *pdev)
 	state->map.write      = gf_write;
 	state->map.copy_to    = gf_copy_to;
 	state->map.bankwidth  = pdata->width;
-	state->map.size       = state->win_size * (1 << state->gpio_count);
+	state->map.size       = BIT(state->win_order + state->gpio_count);
 	state->map.virt	      = devm_ioremap_resource(&pdev->dev, memory);
 	if (IS_ERR(state->map.virt))
 		return PTR_ERR(state->map.virt);
-- 
2.19.0

[PATCH v6 07/10] mtd: maps: gpio-addr-flash: Replace array with an integer

[Ricardo Ribalda Delgado]

By replacing the array with an integer we can avoid completely
the bit comparison loop if the value has not changed (by far
the most common case).

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
---
 drivers/mtd/maps/gpio-addr-flash.c | 34 +++++++++++++++---------------
 1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/drivers/mtd/maps/gpio-addr-flash.c b/drivers/mtd/maps/gpio-addr-flash.c
index 89cc8cce161b..47b12a6fead4 100644
--- a/drivers/mtd/maps/gpio-addr-flash.c
+++ b/drivers/mtd/maps/gpio-addr-flash.c
@@ -43,7 +43,7 @@ struct async_state {
 	struct map_info map;
 	size_t gpio_count;
 	unsigned *gpio_addrs;
-	int *gpio_values;
+	unsigned int gpio_values;
 	unsigned int win_order;
 };
 #define gf_map_info_to_state(mi) ((struct async_state *)(mi)->map_priv_1)
@@ -55,22 +55,25 @@ struct async_state {
  *
  * Rather than call the GPIO framework every time, cache the last-programmed
  * value.  This speeds up sequential accesses (which are by far the most common
- * type).  We rely on the GPIO framework to treat non-zero value as high so
- * that we don't have to normalize the bits.
+ * type).
  */
 static void gf_set_gpios(struct async_state *state, unsigned long ofs)
 {
-	size_t i = 0;
-	int value;
+	int i;
 
 	ofs >>= state->win_order;
-	do {
-		value = ofs & (1 << i);
-		if (state->gpio_values[i] != value) {
-			gpio_set_value(state->gpio_addrs[i], value);
-			state->gpio_values[i] = value;
-		}
-	} while (++i < state->gpio_count);
+
+	if (ofs == state->gpio_values)
+		return;
+
+	for (i = 0; i < state->gpio_count; i++) {
+		if ((ofs & BIT(i)) == (state->gpio_values & BIT(i)))
+			continue;
+
+		gpio_set_value(state->gpio_addrs[i], !!(ofs & BIT(i)));
+	}
+
+	state->gpio_values = ofs;
 }
 
 /**
@@ -202,7 +205,7 @@ static const char * const part_probe_types[] = {
  */
 static int gpio_flash_probe(struct platform_device *pdev)
 {
-	size_t i, arr_size;
+	size_t i;
 	struct physmap_flash_data *pdata;
 	struct resource *memory;
 	struct resource *gpios;
@@ -215,8 +218,7 @@ static int gpio_flash_probe(struct platform_device *pdev)
 	if (!memory || !gpios || !gpios->end)
 		return -EINVAL;
 
-	arr_size = sizeof(int) * gpios->end;
-	state = devm_kzalloc(&pdev->dev, sizeof(*state) + arr_size, GFP_KERNEL);
+	state = devm_kzalloc(&pdev->dev, sizeof(*state), GFP_KERNEL);
 	if (!state)
 		return -ENOMEM;
 
@@ -226,9 +228,7 @@ static int gpio_flash_probe(struct platform_device *pdev)
 	 */
 	state->gpio_count     = gpios->end;
 	state->gpio_addrs     = (void *)(unsigned long)gpios->start;
-	state->gpio_values    = (void *)(state + 1);
 	state->win_order      = get_bitmask_order(resource_size(memory)) - 1;
-	memset(state->gpio_values, 0xff, arr_size);
 
 	state->map.name       = DRIVER_NAME;
 	state->map.read       = gf_read;
-- 
2.19.0

[PATCH v6 08/10] mtd: maps: gpio-addr-flash: Convert to gpiod

[Ricardo Ribalda Delgado]

Convert from legacy gpio API to gpiod.
Board files will have to use gpiod_lookup_tables.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Suggested-by: Boris Brezillon <boris.brezillon@bootlin.com>
---
 drivers/mtd/maps/gpio-addr-flash.c | 55 ++++++++++++------------------
 1 file changed, 21 insertions(+), 34 deletions(-)

diff --git a/drivers/mtd/maps/gpio-addr-flash.c b/drivers/mtd/maps/gpio-addr-flash.c
index 47b12a6fead4..a20e85aa770e 100644
--- a/drivers/mtd/maps/gpio-addr-flash.c
+++ b/drivers/mtd/maps/gpio-addr-flash.c
@@ -14,6 +14,7 @@
  */
 
 #include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
@@ -33,16 +34,14 @@
  * struct async_state - keep GPIO flash state
  *	@mtd:         MTD state for this mapping
  *	@map:         MTD map state for this flash
- *	@gpio_count:  number of GPIOs used to address
- *	@gpio_addrs:  array of GPIOs to twiddle
+ *	@gpios:       Struct containing the array of GPIO descriptors
  *	@gpio_values: cached GPIO values
  *	@win_order:   dedicated memory size (if no GPIOs)
  */
 struct async_state {
 	struct mtd_info *mtd;
 	struct map_info map;
-	size_t gpio_count;
-	unsigned *gpio_addrs;
+	struct gpio_descs *gpios;
 	unsigned int gpio_values;
 	unsigned int win_order;
 };
@@ -66,11 +65,11 @@ static void gf_set_gpios(struct async_state *state, unsigned long ofs)
 	if (ofs == state->gpio_values)
 		return;
 
-	for (i = 0; i < state->gpio_count; i++) {
+	for (i = 0; i < state->gpios->ndescs; i++) {
 		if ((ofs & BIT(i)) == (state->gpio_values & BIT(i)))
 			continue;
 
-		gpio_set_value(state->gpio_addrs[i], !!(ofs & BIT(i)));
+		gpiod_set_value(state->gpios->desc[i], !!(ofs & BIT(i)));
 	}
 
 	state->gpio_values = ofs;
@@ -182,18 +181,22 @@ static const char * const part_probe_types[] = {
  * The platform resource layout expected looks something like:
  * struct mtd_partition partitions[] = { ... };
  * struct physmap_flash_data flash_data = { ... };
- * unsigned flash_gpios[] = { GPIO_XX, GPIO_XX, ... };
+ * static struct gpiod_lookup_table addr_flash_gpios = {
+ *		.dev_id = "gpio-addr-flash.0",
+ *		.table = {
+ *		GPIO_LOOKUP_IDX("gpio.0", 15, "addr", 0, GPIO_ACTIVE_HIGH),
+ *		GPIO_LOOKUP_IDX("gpio.0", 16, "addr", 1, GPIO_ACTIVE_HIGH),
+ *		);
+ * };
+ * gpiod_add_lookup_table(&addr_flash_gpios);
+ *
  * struct resource flash_resource[] = {
  *	{
  *		.name  = "cfi_probe",
  *		.start = 0x20000000,
  *		.end   = 0x201fffff,
  *		.flags = IORESOURCE_MEM,
- *	}, {
- *		.start = (unsigned long)flash_gpios,
- *		.end   = ARRAY_SIZE(flash_gpios),
- *		.flags = IORESOURCE_IRQ,
- *	}
+ *	},
  * };
  * struct platform_device flash_device = {
  *	.name          = "gpio-addr-flash",
@@ -205,29 +208,24 @@ static const char * const part_probe_types[] = {
  */
 static int gpio_flash_probe(struct platform_device *pdev)
 {
-	size_t i;
 	struct physmap_flash_data *pdata;
 	struct resource *memory;
-	struct resource *gpios;
 	struct async_state *state;
 
 	pdata = dev_get_platdata(&pdev->dev);
 	memory = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	gpios = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 
-	if (!memory || !gpios || !gpios->end)
+	if (!memory)
 		return -EINVAL;
 
 	state = devm_kzalloc(&pdev->dev, sizeof(*state), GFP_KERNEL);
 	if (!state)
 		return -ENOMEM;
 
-	/*
-	 * We cast start/end to known types in the boards file, so cast
-	 * away their pointer types here to the known types (gpios->xxx).
-	 */
-	state->gpio_count     = gpios->end;
-	state->gpio_addrs     = (void *)(unsigned long)gpios->start;
+	state->gpios = devm_gpiod_get_array(&pdev->dev, "addr", GPIOD_OUT_LOW);
+	if (IS_ERR(state->gpios))
+		return PTR_ERR(state->gpios);
+
 	state->win_order      = get_bitmask_order(resource_size(memory)) - 1;
 
 	state->map.name       = DRIVER_NAME;
@@ -236,7 +234,7 @@ static int gpio_flash_probe(struct platform_device *pdev)
 	state->map.write      = gf_write;
 	state->map.copy_to    = gf_copy_to;
 	state->map.bankwidth  = pdata->width;
-	state->map.size       = BIT(state->win_order + state->gpio_count);
+	state->map.size       = BIT(state->win_order + state->gpios->ndescs);
 	state->map.virt	      = devm_ioremap_resource(&pdev->dev, memory);
 	if (IS_ERR(state->map.virt))
 		return PTR_ERR(state->map.virt);
@@ -246,17 +244,6 @@ static int gpio_flash_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, state);
 
-	i = 0;
-	do {
-		if (devm_gpio_request(&pdev->dev, state->gpio_addrs[i],
-				      DRIVER_NAME)) {
-			dev_err(&pdev->dev, "failed to request gpio %d\n",
-				state->gpio_addrs[i]);
-			return -EBUSY;
-		}
-		gpio_direction_output(state->gpio_addrs[i], 0);
-	} while (++i < state->gpio_count);
-
 	dev_notice(&pdev->dev, "probing %d-bit flash bus\n",
 		   state->map.bankwidth * 8);
 	state->mtd = do_map_probe(memory->name, &state->map);
-- 
2.19.0

[PATCH v6 09/10] dt-binding: mtd: Document gpio-addr-flash

[Ricardo Ribalda Delgado]

Add documentation for gpio-addr-flash. This binding allow creating
flash devices that are paged using GPIOs.

Cc: devicetree@vger.kernel.org
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
---
 .../bindings/mtd/mtd,gpio-addr-flash.txt      | 25 +++++++++++++++++++
 1 file changed, 25 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mtd/mtd,gpio-addr-flash.txt

diff --git a/Documentation/devicetree/bindings/mtd/mtd,gpio-addr-flash.txt b/Documentation/devicetree/bindings/mtd/mtd,gpio-addr-flash.txt
new file mode 100644
index 000000000000..304a33880f9e
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/mtd,gpio-addr-flash.txt
@@ -0,0 +1,25 @@
+Memory Mapped flash with some address lines addressed using GPIOs
+
+Handle the case where a flash device is mostly addressed using physical
+line and supplemented by GPIOs.  This way you can hook up say a 8MiB flash
+to a 2MiB memory range and use the GPIOs to select a particular range.
+
+ - compatible :  must be "mtd,gpio-addr-flash", "cfi-flash";
+ - reg : Address range of the mtd chip that is memory mapped, this is,
+   on the previous example 2MiB.
+ - addr-gpios: List of GPIO specifiers that will be used to address the MSBs
+   address lines. The order goes from LSB to MSB.
+
+For the rest of the properties, see mtd-physmap.txt.
+
+The device tree may optionally contain sub-nodes describing partitions of the
+address space. Check partition.txt for more details.
+
+Example:
+
+	flash@300000 {
+		compatible = "mtd,gpio-addr-flash", "cfi-flash";
+		bank-width = <2>;
+		reg = < 0x00300000 0x00200000 >;
+		addr-gpios = <&gpio_0 3 0>, <&gpio_0 4 0>;
+	} ;
-- 
2.19.0

[PATCH v6 10/10] mtd: maps: gpio-addr-flash: Add support for device-tree devices

[Ricardo Ribalda Delgado]

Allow creating gpio-addr-flash via device-tree and not just via platform
data.

Mimic what physmap_of_versatile and physmap_of_gemini does to reduce
code duplicity.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
---
 drivers/mtd/maps/Kconfig           |  8 +++
 drivers/mtd/maps/Makefile          |  3 +-
 drivers/mtd/maps/gpio-addr-flash.c | 91 ++++++++++++++++++------------
 drivers/mtd/maps/gpio-addr-flash.h | 31 ++++++++++
 drivers/mtd/maps/physmap_of_core.c |  7 +++
 drivers/mtd/maps/physmap_of_gpio.c | 24 ++++++++
 6 files changed, 127 insertions(+), 37 deletions(-)
 create mode 100644 drivers/mtd/maps/gpio-addr-flash.h
 create mode 100644 drivers/mtd/maps/physmap_of_gpio.c

diff --git a/drivers/mtd/maps/Kconfig b/drivers/mtd/maps/Kconfig
index afb36bff13a7..427143d42168 100644
--- a/drivers/mtd/maps/Kconfig
+++ b/drivers/mtd/maps/Kconfig
@@ -94,6 +94,14 @@ config MTD_PHYSMAP_OF_GEMINI
 	  platforms, some detection and setting up parallel mode on the
 	  external interface.
 
+config MTD_PHYSMAP_OF_GPIO
+	bool "GPIO-assisted OF-based physical memory map handling"
+	depends on MTD_PHYSMAP_OF
+	depends on MTD_GPIO_ADDR
+	help
+	  This provides some extra DT physmap parsing for flashes that are
+	  partially physically addressed and assisted by GPIOs.
+
 config MTD_PMC_MSP_EVM
 	tristate "CFI Flash device mapped on PMC-Sierra MSP"
 	depends on PMC_MSP && MTD_CFI
diff --git a/drivers/mtd/maps/Makefile b/drivers/mtd/maps/Makefile
index 51acf1fec19b..c232ccf05bee 100644
--- a/drivers/mtd/maps/Makefile
+++ b/drivers/mtd/maps/Makefile
@@ -21,6 +21,7 @@ obj-$(CONFIG_MTD_PHYSMAP)	+= physmap.o
 physmap_of-objs-y		+= physmap_of_core.o
 physmap_of-objs-$(CONFIG_MTD_PHYSMAP_OF_VERSATILE) += physmap_of_versatile.o
 physmap_of-objs-$(CONFIG_MTD_PHYSMAP_OF_GEMINI) += physmap_of_gemini.o
+physmap_of-objs-$(CONFIG_MTD_PHYSMAP_OF_GPIO) += physmap_of_gpio.o
 physmap_of-objs			:= $(physmap_of-objs-y)
 obj-$(CONFIG_MTD_PHYSMAP_OF)	+= physmap_of.o
 obj-$(CONFIG_MTD_PISMO)		+= pismo.o
@@ -44,6 +45,6 @@ obj-$(CONFIG_MTD_PLATRAM)	+= plat-ram.o
 obj-$(CONFIG_MTD_INTEL_VR_NOR)	+= intel_vr_nor.o
 obj-$(CONFIG_MTD_RBTX4939)	+= rbtx4939-flash.o
 obj-$(CONFIG_MTD_VMU)		+= vmu-flash.o
-obj-$(CONFIG_MTD_GPIO_ADDR)	+= gpio-addr-flash.o
+obj-$(CONFIG_MTD_GPIO_ADDR)    += gpio-addr-flash.o
 obj-$(CONFIG_MTD_LATCH_ADDR)	+= latch-addr-flash.o
 obj-$(CONFIG_MTD_LANTIQ)	+= lantiq-flash.o
diff --git a/drivers/mtd/maps/gpio-addr-flash.c b/drivers/mtd/maps/gpio-addr-flash.c
index a20e85aa770e..7837fc7b8de8 100644
--- a/drivers/mtd/maps/gpio-addr-flash.c
+++ b/drivers/mtd/maps/gpio-addr-flash.c
@@ -25,25 +25,25 @@
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/types.h>
+#include "gpio-addr-flash.h"
 
 #define win_mask(x) ((BIT(x)) - 1)
 
 #define DRIVER_NAME "gpio-addr-flash"
 
+#define gf_map_info_to_state(mi) ((struct async_state *)(mi)->map_priv_1)
+
 /**
- * struct async_state - keep GPIO flash state
+ * struct async_state_pdev - Async state platform device
  *	@mtd:         MTD state for this mapping
  *	@map:         MTD map state for this flash
  *	@gpios:       Struct containing the array of GPIO descriptors
- *	@gpio_values: cached GPIO values
- *	@win_order:   dedicated memory size (if no GPIOs)
+ *	@state:       GPIO flash state
  */
-struct async_state {
+struct async_state_pdev {
 	struct mtd_info *mtd;
 	struct map_info map;
-	struct gpio_descs *gpios;
-	unsigned int gpio_values;
-	unsigned int win_order;
+	struct async_state state;
 };
 #define gf_map_info_to_state(mi) ((struct async_state *)(mi)->map_priv_1)
 
@@ -174,6 +174,31 @@ static void gf_copy_to(struct map_info *map, unsigned long to,
 static const char * const part_probe_types[] = {
 	"cmdlinepart", "RedBoot", NULL };
 
+int gpio_flash_probe_common(struct device *dev, struct async_state *state,
+			    struct map_info *map)
+{
+	if (!is_power_of_2(map->size)) {
+		dev_err(dev, "Window size must be aligned\n");
+		return -EIO;
+	}
+
+	state->gpios = devm_gpiod_get_array(dev, "addr", GPIOD_OUT_LOW);
+	if (IS_ERR(state->gpios))
+		return PTR_ERR(state->gpios);
+
+	state->win_order  = get_bitmask_order(map->size) - 1;
+	map->read       = gf_read;
+	map->copy_from  = gf_copy_from;
+	map->write      = gf_write;
+	map->copy_to    = gf_copy_to;
+	map->size       = BIT(state->win_order + state->gpios->ndescs);
+	map->phys	= NO_XIP;
+	map->map_priv_1 = (unsigned long)state;
+
+	return 0;
+}
+EXPORT_SYMBOL(gpio_flash_probe_common);
+
 /**
  * gpio_flash_probe() - setup a mapping for a GPIO assisted flash
  *	@pdev: platform device
@@ -210,7 +235,8 @@ static int gpio_flash_probe(struct platform_device *pdev)
 {
 	struct physmap_flash_data *pdata;
 	struct resource *memory;
-	struct async_state *state;
+	struct async_state_pdev *state_pdev;
+	int ret;
 
 	pdata = dev_get_platdata(&pdev->dev);
 	memory = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -218,40 +244,33 @@ static int gpio_flash_probe(struct platform_device *pdev)
 	if (!memory)
 		return -EINVAL;
 
-	state = devm_kzalloc(&pdev->dev, sizeof(*state), GFP_KERNEL);
-	if (!state)
+	state_pdev = devm_kzalloc(&pdev->dev, sizeof(*state_pdev), GFP_KERNEL);
+	if (!state_pdev)
 		return -ENOMEM;
 
-	state->gpios = devm_gpiod_get_array(&pdev->dev, "addr", GPIOD_OUT_LOW);
-	if (IS_ERR(state->gpios))
-		return PTR_ERR(state->gpios);
-
-	state->win_order      = get_bitmask_order(resource_size(memory)) - 1;
+	state_pdev->map.virt = devm_ioremap_resource(&pdev->dev, memory);
+	if (IS_ERR(state_pdev->map.virt))
+		return PTR_ERR(state_pdev->map.virt);
 
-	state->map.name       = DRIVER_NAME;
-	state->map.read       = gf_read;
-	state->map.copy_from  = gf_copy_from;
-	state->map.write      = gf_write;
-	state->map.copy_to    = gf_copy_to;
-	state->map.bankwidth  = pdata->width;
-	state->map.size       = BIT(state->win_order + state->gpios->ndescs);
-	state->map.virt	      = devm_ioremap_resource(&pdev->dev, memory);
-	if (IS_ERR(state->map.virt))
-		return PTR_ERR(state->map.virt);
+	state_pdev->map.name       = DRIVER_NAME;
+	state_pdev->map.bankwidth  = pdata->width;
+	state_pdev->map.size       = resource_size(memory);
 
-	state->map.phys       = NO_XIP;
-	state->map.map_priv_1 = (unsigned long)state;
+	ret = gpio_flash_probe_common(&pdev->dev, &state_pdev->state,
+				      &state_pdev->map);
+	if (ret)
+		return ret;
 
-	platform_set_drvdata(pdev, state);
+	platform_set_drvdata(pdev, state_pdev);
 
 	dev_notice(&pdev->dev, "probing %d-bit flash bus\n",
-		   state->map.bankwidth * 8);
-	state->mtd = do_map_probe(memory->name, &state->map);
-	if (!state->mtd)
+		   state_pdev->map.bankwidth * 8);
+	state_pdev->mtd = do_map_probe(memory->name, &state_pdev->map);
+	if (!state_pdev->mtd)
 		return -ENXIO;
-	state->mtd->dev.parent = &pdev->dev;
+	state_pdev->mtd->dev.parent = &pdev->dev;
 
-	mtd_device_parse_register(state->mtd, part_probe_types, NULL,
+	mtd_device_parse_register(state_pdev->mtd, part_probe_types, NULL,
 				  pdata->parts, pdata->nr_parts);
 
 	return 0;
@@ -259,10 +278,10 @@ static int gpio_flash_probe(struct platform_device *pdev)
 
 static int gpio_flash_remove(struct platform_device *pdev)
 {
-	struct async_state *state = platform_get_drvdata(pdev);
+	struct async_state_pdev *state_pdev = platform_get_drvdata(pdev);
 
-	mtd_device_unregister(state->mtd);
-	map_destroy(state->mtd);
+	mtd_device_unregister(state_pdev->mtd);
+	map_destroy(state_pdev->mtd);
 	return 0;
 }
 
diff --git a/drivers/mtd/maps/gpio-addr-flash.h b/drivers/mtd/maps/gpio-addr-flash.h
new file mode 100644
index 000000000000..46d97a8031eb
--- /dev/null
+++ b/drivers/mtd/maps/gpio-addr-flash.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/of.h>
+#include <linux/mtd/map.h>
+
+/**
+ * struct async_state - keep GPIO flash state
+ *	@gpios:       Struct containing the array of GPIO descriptors
+ *	@gpio_values: cached GPIO values
+ *	@win_order:   dedicated memory size (if no GPIOs)
+ */
+struct async_state {
+	struct gpio_descs *gpios;
+	unsigned int gpio_values;
+	unsigned int win_order;
+};
+
+int gpio_flash_probe_common(struct device *dev,
+				   struct async_state *state,
+				   struct map_info *map);
+
+#ifdef CONFIG_MTD_PHYSMAP_OF_GPIO
+int of_flash_probe_gpio(struct platform_device *pdev, struct device_node *np,
+			struct map_info *map);
+#else
+static inline
+int of_flash_probe_gpio(struct platform_device *pdev, struct device_node *np,
+			struct map_info *map)
+{
+	return 0;
+}
+#endif
diff --git a/drivers/mtd/maps/physmap_of_core.c b/drivers/mtd/maps/physmap_of_core.c
index 062add8b3a6e..19a300232969 100644
--- a/drivers/mtd/maps/physmap_of_core.c
+++ b/drivers/mtd/maps/physmap_of_core.c
@@ -27,6 +27,7 @@
 #include <linux/slab.h>
 #include "physmap_of_gemini.h"
 #include "physmap_of_versatile.h"
+#include "gpio-addr-flash.h"
 
 struct of_flash_list {
 	struct mtd_info *mtd;
@@ -257,6 +258,12 @@ static int of_flash_probe(struct platform_device *dev)
 
 		simple_map_init(&info->list[i].map);
 
+		err = of_flash_probe_gpio(dev, dp, &info->list[i].map);
+		if (err){
+			iounmap(info->list[i].map.virt);
+			goto err_out;
+		}
+
 		/*
 		 * On some platforms (e.g. MPC5200) a direct 1:1 mapping
 		 * may cause problems with JFFS2 usage, as the local bus (LPB)
diff --git a/drivers/mtd/maps/physmap_of_gpio.c b/drivers/mtd/maps/physmap_of_gpio.c
new file mode 100644
index 000000000000..97e02737ed67
--- /dev/null
+++ b/drivers/mtd/maps/physmap_of_gpio.c
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2018 Qtechnology A/S
+ *
+ * Ricardo Ribalda <ricardo.ribalda@gmail.com>
+ *
+ */
+#include <linux/platform_device.h>
+#include "gpio-addr-flash.h"
+
+int of_flash_probe_gpio(struct platform_device *pdev, struct device_node *np,
+			struct map_info *map)
+{
+	struct async_state *state;
+
+	if (!of_device_is_compatible(np, "mtd,gpio-addr-flash"))
+		return 0;
+
+	state = devm_kzalloc(&pdev->dev, sizeof(*state), GFP_KERNEL);
+	if (!state)
+		return -ENOMEM;
+
+	return gpio_flash_probe_common(&pdev->dev, state, map);
+}
-- 
2.19.0

Re: [PATCH v6 01/10] mtd: physmap_of: Release resources on error

[Boris Brezillon]

Hi Ricardo,

On Thu,  4 Oct 2018 15:01:01 +0200
Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> wrote:

> During probe, if there was an error the memory region and the memory
> map were not properly released.
> 
> This can lead a system unusable if deferred probe is in use.
> 
> Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
> ---
>  drivers/mtd/maps/physmap_of_core.c | 12 ++++++++----
>  1 file changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/mtd/maps/physmap_of_core.c b/drivers/mtd/maps/physmap_of_core.c
> index 4129535b8e46..062add8b3a6e 100644
> --- a/drivers/mtd/maps/physmap_of_core.c
> +++ b/drivers/mtd/maps/physmap_of_core.c
> @@ -241,10 +241,10 @@ static int of_flash_probe(struct platform_device *dev)
>  
>  		err = of_flash_probe_gemini(dev, dp, &info->list[i].map);
>  		if (err)
> -			goto err_out;
> +			goto err_out_release;
>  		err = of_flash_probe_versatile(dev, dp, &info->list[i].map);
>  		if (err)
> -			goto err_out;
> +			goto err_out_release;
>  
>  		err = -ENOMEM;
>  		info->list[i].map.virt = ioremap(info->list[i].map.phys,
> @@ -252,7 +252,7 @@ static int of_flash_probe(struct platform_device *dev)
>  		if (!info->list[i].map.virt) {
>  			dev_err(&dev->dev, "Failed to ioremap() flash"
>  				" region\n");
> -			goto err_out;
> +			goto err_out_release;
>  		}
>  
>  		simple_map_init(&info->list[i].map);
> @@ -290,7 +290,7 @@ static int of_flash_probe(struct platform_device *dev)
>  		err = -ENXIO;
>  		if (!info->list[i].mtd) {
>  			dev_err(&dev->dev, "do_map_probe() failed\n");
> -			goto err_out;
> +			goto err_out_iounmap;
>  		} else {
>  			info->list_size++;
>  		}
> @@ -329,6 +329,10 @@ static int of_flash_probe(struct platform_device *dev)
>  
>  	return 0;
>  
> +err_out_iounmap:
> +	iounmap(info->list[i].map.virt);
> +err_out_release:
> +	release_mem_region(res.start, resource_size(&res));
>  err_out:
>  	kfree(mtd_list);
>  err_flash_remove:

Please fix that using devm_ioremap_resource() instead.

Thanks,

Boris

Re: [PATCH v6 02/10] mtd: physmap_of: Remove unused struct of_device_id

[Boris Brezillon]

On Thu,  4 Oct 2018 15:01:02 +0200
Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> wrote:

> This struct does not seem to be used anywhere on the code
> 
> Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>

Already queued that one.

> ---
>  drivers/mtd/maps/physmap_of_gemini.c | 5 -----
>  1 file changed, 5 deletions(-)
> 
> diff --git a/drivers/mtd/maps/physmap_of_gemini.c b/drivers/mtd/maps/physmap_of_gemini.c
> index 830b1b7e702b..9df62ca721d5 100644
> --- a/drivers/mtd/maps/physmap_of_gemini.c
> +++ b/drivers/mtd/maps/physmap_of_gemini.c
> @@ -44,11 +44,6 @@
>  
>  #define FLASH_PARALLEL_HIGH_PIN_CNT	(1 << 20)	/* else low pin cnt */
>  
> -static const struct of_device_id syscon_match[] = {
> -	{ .compatible = "cortina,gemini-syscon" },
> -	{ },
> -};
> -
>  int of_flash_probe_gemini(struct platform_device *pdev,
>  			  struct device_node *np,
>  			  struct map_info *map)

Re: [PATCH v6 09/10] dt-binding: mtd: Document gpio-addr-flash

[Boris Brezillon]

On Thu,  4 Oct 2018 15:01:09 +0200
Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> wrote:

> Add documentation for gpio-addr-flash. This binding allow creating
> flash devices that are paged using GPIOs.
> 
> Cc: devicetree@vger.kernel.org
> Reviewed-by: Rob Herring <robh@kernel.org>
> Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
> ---
>  .../bindings/mtd/mtd,gpio-addr-flash.txt      | 25 +++++++++++++++++++
>  1 file changed, 25 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mtd/mtd,gpio-addr-flash.txt
> 
> diff --git a/Documentation/devicetree/bindings/mtd/mtd,gpio-addr-flash.txt b/Documentation/devicetree/bindings/mtd/mtd,gpio-addr-flash.txt
> new file mode 100644
> index 000000000000..304a33880f9e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mtd/mtd,gpio-addr-flash.txt
> @@ -0,0 +1,25 @@
> +Memory Mapped flash with some address lines addressed using GPIOs
> +
> +Handle the case where a flash device is mostly addressed using physical
> +line and supplemented by GPIOs.  This way you can hook up say a 8MiB flash
> +to a 2MiB memory range and use the GPIOs to select a particular range.
> +
> + - compatible :  must be "mtd,gpio-addr-flash", "cfi-flash";

I keep thinking you don't need a specific binding, just add an optional
addr-gpios property to the generic physmap binding and that should do
the trick. Plus, "*mtd*,gpio-addr-flash" is a linux-ism, and DT
bindings should be OS-agnostic.

> + - reg : Address range of the mtd chip that is memory mapped, this is,
> +   on the previous example 2MiB.
> + - addr-gpios: List of GPIO specifiers that will be used to address the MSBs
> +   address lines. The order goes from LSB to MSB.
> +
> +For the rest of the properties, see mtd-physmap.txt.
> +
> +The device tree may optionally contain sub-nodes describing partitions of the
> +address space. Check partition.txt for more details.
> +
> +Example:
> +
> +	flash@300000 {
> +		compatible = "mtd,gpio-addr-flash", "cfi-flash";
> +		bank-width = <2>;
> +		reg = < 0x00300000 0x00200000 >;
> +		addr-gpios = <&gpio_0 3 0>, <&gpio_0 4 0>;
> +	} ;

Re: [PATCH v6 09/10] dt-binding: mtd: Document gpio-addr-flash

[Ricardo Ribalda Delgado]

Hi Boris
On Thu, Oct 4, 2018 at 4:02 PM Boris Brezillon
<boris.brezillon@bootlin.com> wrote:
>
> On Thu,  4 Oct 2018 15:01:09 +0200
> Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> wrote:
>
> > Add documentation for gpio-addr-flash. This binding allow creating
> > flash devices that are paged using GPIOs.
> >
> > Cc: devicetree@vger.kernel.org
> > Reviewed-by: Rob Herring <robh@kernel.org>
> > Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
> > ---
> >  .../bindings/mtd/mtd,gpio-addr-flash.txt      | 25 +++++++++++++++++++
> >  1 file changed, 25 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/mtd/mtd,gpio-addr-flash.txt
> >
> > diff --git a/Documentation/devicetree/bindings/mtd/mtd,gpio-addr-flash.txt b/Documentation/devicetree/bindings/mtd/mtd,gpio-addr-flash.txt
> > new file mode 100644
> > index 000000000000..304a33880f9e
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/mtd/mtd,gpio-addr-flash.txt
> > @@ -0,0 +1,25 @@
> > +Memory Mapped flash with some address lines addressed using GPIOs
> > +
> > +Handle the case where a flash device is mostly addressed using physical
> > +line and supplemented by GPIOs.  This way you can hook up say a 8MiB flash
> > +to a 2MiB memory range and use the GPIOs to select a particular range.
> > +
> > + - compatible :  must be "mtd,gpio-addr-flash", "cfi-flash";
>
> I keep thinking you don't need a specific binding, just add an optional
> addr-gpios property to the generic physmap binding and that should do
> the trick. Plus, "*mtd*,gpio-addr-flash" is a linux-ism, and DT
> bindings should be OS-agnostic.
>

That is a very good point. Please take a look to v10, and tell me what
do you think.

It does not require a specific binding and also it can be build optionally.

Regards!

> > + - reg : Address range of the mtd chip that is memory mapped, this is,
> > +   on the previous example 2MiB.
> > + - addr-gpios: List of GPIO specifiers that will be used to address the MSBs
> > +   address lines. The order goes from LSB to MSB.
> > +
> > +For the rest of the properties, see mtd-physmap.txt.
> > +
> > +The device tree may optionally contain sub-nodes describing partitions of the
> > +address space. Check partition.txt for more details.
> > +
> > +Example:
> > +
> > +     flash@300000 {
> > +             compatible = "mtd,gpio-addr-flash", "cfi-flash";
> > +             bank-width = <2>;
> > +             reg = < 0x00300000 0x00200000 >;
> > +             addr-gpios = <&gpio_0 3 0>, <&gpio_0 4 0>;
> > +     } ;
>


-- 
Ricardo Ribalda