[PATCH v5 1/8] mtd: maps: gpio-addr-flash: Replace custom printk

[PATCH v5 1/8] 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 v5 2/8] 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 v5 3/8] 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 v5 4/8] 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 v5 5/8] 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 v5 6/8] 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 | 52 +++++++++++-------------------
 1 file changed, 18 insertions(+), 34 deletions(-)

diff --git a/drivers/mtd/maps/gpio-addr-flash.c b/drivers/mtd/maps/gpio-addr-flash.c
index 47b12a6fead4..9e370e3158cd 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 +181,19 @@ 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 = { .... );
+ * };
+ * 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 +205,24 @@ 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, NULL, 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 +231,7 @@ 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 +241,6 @@ 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 v5 7/8] 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/gpio-addr-flash.txt          | 54 +++++++++++++++++++
 1 file changed, 54 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt

diff --git a/Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt b/Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt
new file mode 100644
index 000000000000..5006a26e1753
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt
@@ -0,0 +1,54 @@
+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 : "cfi-gpio-addr-flash"
+ - reg : Address range of the mtd chip that is memory mapped, this is,
+   on the previous example 2MiB.
+ - bank-width : Width (in bytes) of the bank.  Equal to the
+   device width times the number of interleaved chips.
+ - gpios: List of GPIO specifiers that will be used to address the MSBs address
+   lines. The order goes from LSB to MSB.
+ - probe-type : (optional) "cfi_probe", "jedec_probe". How the mtd chip
+   is going to be probed. If omitted, assumed to be equal to "cfi_probe".
+ - #address-cells, #size-cells : Must be present if the device has
+   sub-nodes representing partitions (see below).  In this case
+   both #address-cells and #size-cells must be equal to 1.
+
+The device tree may optionally contain sub-nodes describing partitions of the
+address space. Check partition.txt for more details.
+
+Example:
+
+	flash@300000 {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		compatible = "cfi-gpio-addr-flash";
+		bank-width = <2>;
+		reg = < 0x00300000 0x00200000 >;
+		gpios = <&gpio_0 3 0>, <&gpio_0 4 0>;
+		partitions {
+			compatible = "fixed-partitions";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			partition@0 {
+				reg = < 0x0 0x200000 >;
+				label = "Golden Bitstream";
+			};
+			partition@200000 {
+				reg = < 0x200000 0x200000 >;
+				label = "User Bitstream";
+			};
+			partition@400000 {
+				reg = < 0x400000 0x200000 >;
+				label = "V4L Controls";
+			};
+			partition@600000 {
+				reg = < 0x600000 0x200000 >;
+				label = "Production Data";
+			};
+		}
+	} ;
-- 
2.19.0

[PATCH v5 8/8] 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.

Option parsing has been moved to separated functions.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
---
 drivers/mtd/maps/gpio-addr-flash.c | 95 +++++++++++++++++++++++++++---
 1 file changed, 87 insertions(+), 8 deletions(-)

diff --git a/drivers/mtd/maps/gpio-addr-flash.c b/drivers/mtd/maps/gpio-addr-flash.c
index 9e370e3158cd..1be2df81087a 100644
--- a/drivers/mtd/maps/gpio-addr-flash.c
+++ b/drivers/mtd/maps/gpio-addr-flash.c
@@ -7,6 +7,7 @@
  *
  * Copyright © 2000 Nicolas Pitre <nico@cam.org>
  * Copyright © 2005-2009 Analog Devices Inc.
+ * Copyright © 2018 Ricardo Ribalda <ricardo.ribalda@gmail.com>
  *
  * Enter bugs at http://blackfin.uclinux.org/
  *
@@ -171,8 +172,67 @@ static void gf_copy_to(struct map_info *map, unsigned long to,
 	}
 }
 
-static const char * const part_probe_types[] = {
-	"cmdlinepart", "RedBoot", NULL };
+static int gf_bankwidth(struct platform_device *pdev)
+{
+	struct device_node *dn;
+	int ret;
+	u32 bankwidth;
+
+	dn = pdev->dev.of_node;
+	if (!dn) {
+		struct physmap_flash_data *pdata;
+
+		pdata = dev_get_platdata(&pdev->dev);
+		return pdata->width;
+	}
+
+	ret = of_property_read_u32(dn, "bank-width", &bankwidth);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to get bank-width\n");
+		return -EINVAL;
+	}
+
+	return bankwidth;
+}
+
+static const char *gf_probe_type(struct platform_device *pdev)
+{
+	struct device_node *dn;
+	struct resource *memory;
+	const char *of_probe;
+
+	dn = pdev->dev.of_node;
+	if (!dn) {
+		memory = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+		return memory->name;
+	}
+
+	of_probe = of_get_property(dn, "probe-type", NULL);
+	if (of_probe)
+		return of_probe;
+
+	return "cfi_probe";
+}
+
+static void gf_device_parse_register(struct platform_device *pdev,
+				     struct async_state *state)
+{
+	static const char * const part_probe_types[] = {
+		"cmdlinepart", "RedBoot", "ofpart", "ofoldpart", NULL };
+	struct device_node *dn;
+
+	dn = pdev->dev.of_node;
+	if (!dn) {
+		struct physmap_flash_data *pdata;
+
+		pdata = dev_get_platdata(&pdev->dev);
+		mtd_device_parse_register(state->mtd, part_probe_types, NULL,
+					  pdata->parts, pdata->nr_parts);
+		return;
+	}
+
+	mtd_device_parse_register(state->mtd, part_probe_types, NULL, NULL, 0);
+}
 
 /**
  * gpio_flash_probe() - setup a mapping for a GPIO assisted flash
@@ -208,6 +268,7 @@ static int gpio_flash_probe(struct platform_device *pdev)
 	struct physmap_flash_data *pdata;
 	struct resource *memory;
 	struct async_state *state;
+	int ret;
 
 	pdata = dev_get_platdata(&pdev->dev);
 	memory = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -215,9 +276,15 @@ static int gpio_flash_probe(struct platform_device *pdev)
 	if (!memory)
 		return -EINVAL;
 
+	if (!is_power_of_2(resource_size(memory))) {
+		dev_err(&pdev->dev, "Window size must be aligned\n");
+		return -EIO;
+	}
+
 	state = devm_kzalloc(&pdev->dev, sizeof(*state), GFP_KERNEL);
 	if (!state)
 		return -ENOMEM;
+	platform_set_drvdata(pdev, state);
 
 	state->gpios = devm_gpiod_get_array(&pdev->dev, NULL, GPIOD_OUT_LOW);
 	if (IS_ERR(state->gpios))
@@ -230,7 +297,12 @@ static int gpio_flash_probe(struct platform_device *pdev)
 	state->map.copy_from  = gf_copy_from;
 	state->map.write      = gf_write;
 	state->map.copy_to    = gf_copy_to;
-	state->map.bankwidth  = pdata->width;
+
+	ret = gf_bankwidth(pdev);
+	if (ret < 0)
+		return ret;
+	state->map.bankwidth = ret;
+
 	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))
@@ -239,17 +311,15 @@ static int gpio_flash_probe(struct platform_device *pdev)
 	state->map.phys       = NO_XIP;
 	state->map.map_priv_1 = (unsigned long)state;
 
-	platform_set_drvdata(pdev, state);
-
 	dev_notice(&pdev->dev, "probing %d-bit flash bus\n",
 		   state->map.bankwidth * 8);
-	state->mtd = do_map_probe(memory->name, &state->map);
+	state->mtd = do_map_probe(gf_probe_type(pdev), &state->map);
 	if (!state->mtd)
 		return -ENXIO;
 	state->mtd->dev.parent = &pdev->dev;
+	mtd_set_of_node(state->mtd, pdev->dev.of_node);
 
-	mtd_device_parse_register(state->mtd, part_probe_types, NULL,
-				  pdata->parts, pdata->nr_parts);
+	gf_device_parse_register(pdev, state);
 
 	return 0;
 }
@@ -263,11 +333,20 @@ static int gpio_flash_remove(struct platform_device *pdev)
 	return 0;
 }
 
+static const struct of_device_id gpio_flash_match[] = {
+	{
+		.compatible	= "cfi-gpio-addr-flash",
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, gpio_flash_match);
+
 static struct platform_driver gpio_flash_driver = {
 	.probe		= gpio_flash_probe,
 	.remove		= gpio_flash_remove,
 	.driver		= {
 		.name	= DRIVER_NAME,
+		.of_match_table = gpio_flash_match,
 	},
 };
 
-- 
2.19.0

Re: [PATCH v5 7/8] dt-binding: mtd: Document gpio-addr-flash

[Boris Brezillon]

On Wed,  3 Oct 2018 21:38:58 +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/gpio-addr-flash.txt          | 54 +++++++++++++++++++
>  1 file changed, 54 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt
> 
> diff --git a/Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt b/Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt
> new file mode 100644
> index 000000000000..5006a26e1753
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt
> @@ -0,0 +1,54 @@
> +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 : "cfi-gpio-addr-flash"
> + - reg : Address range of the mtd chip that is memory mapped, this is,
> +   on the previous example 2MiB.
> + - bank-width : Width (in bytes) of the bank.  Equal to the
> +   device width times the number of interleaved chips.
> + - gpios: List of GPIO specifiers that will be used to address the MSBs address
> +   lines. The order goes from LSB to MSB.

I'd recommend naming the GPIO set (addr-gpios or msb-addr-gpios?), just
to make things clear.

> + - probe-type : (optional) "cfi_probe", "jedec_probe". How the mtd chip
> +   is going to be probed. If omitted, assumed to be equal to "cfi_probe".
> + - #address-cells, #size-cells : Must be present if the device has
> +   sub-nodes representing partitions (see below).  In this case
> +   both #address-cells and #size-cells must be equal to 1.
> +
> +The device tree may optionally contain sub-nodes describing partitions of the
> +address space. Check partition.txt for more details.
> +
> +Example:
> +
> +	flash@300000 {
> +		#address-cells = <1>;
> +		#size-cells = <1>;
> +		compatible = "cfi-gpio-addr-flash";
> +		bank-width = <2>;
> +		reg = < 0x00300000 0x00200000 >;
> +		gpios = <&gpio_0 3 0>, <&gpio_0 4 0>;
> +		partitions {
> +			compatible = "fixed-partitions";
> +			#address-cells = <1>;
> +			#size-cells = <1>;
> +
> +			partition@0 {
> +				reg = < 0x0 0x200000 >;
> +				label = "Golden Bitstream";
> +			};
> +			partition@200000 {
> +				reg = < 0x200000 0x200000 >;
> +				label = "User Bitstream";
> +			};
> +			partition@400000 {
> +				reg = < 0x400000 0x200000 >;
> +				label = "V4L Controls";
> +			};
> +			partition@600000 {
> +				reg = < 0x600000 0x200000 >;
> +				label = "Production Data";
> +			};
> +		}
> +	} ;

Re: [PATCH v5 8/8] mtd: maps: gpio-addr-flash: Add support for device-tree devices

[Boris Brezillon]

On Wed,  3 Oct 2018 21:38:59 +0200
Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> wrote:

> Allow creating gpio-addr-flash via device-tree and not just via platform
> data.
> 
> Option parsing has been moved to separated functions.
> 
> Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
> ---
>  drivers/mtd/maps/gpio-addr-flash.c | 95 +++++++++++++++++++++++++++---
>  1 file changed, 87 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/mtd/maps/gpio-addr-flash.c b/drivers/mtd/maps/gpio-addr-flash.c
> index 9e370e3158cd..1be2df81087a 100644
> --- a/drivers/mtd/maps/gpio-addr-flash.c
> +++ b/drivers/mtd/maps/gpio-addr-flash.c
> @@ -7,6 +7,7 @@
>   *
>   * Copyright © 2000 Nicolas Pitre <nico@cam.org>
>   * Copyright © 2005-2009 Analog Devices Inc.
> + * Copyright © 2018 Ricardo Ribalda <ricardo.ribalda@gmail.com>

Would you mind moving the copyright update to a separate patch?


> +
> +static void gf_device_parse_register(struct platform_device *pdev,
> +				     struct async_state *state)
> +{
> +	static const char * const part_probe_types[] = {
> +		"cmdlinepart", "RedBoot", "ofpart", "ofoldpart", NULL };
> +	struct device_node *dn;
> +
> +	dn = pdev->dev.of_node;
> +	if (!dn) {
> +		struct physmap_flash_data *pdata;
> +
> +		pdata = dev_get_platdata(&pdev->dev);
> +		mtd_device_parse_register(state->mtd, part_probe_types, NULL,
> +					  pdata->parts, pdata->nr_parts);
> +		return;
> +	}
> +
> +	mtd_device_parse_register(state->mtd, part_probe_types, NULL, NULL, 0);


Looks like you keep ignoring the mtd_device_parse_register() return.
Probably something you should fix at some point.

Re: [PATCH v5 7/8] dt-binding: mtd: Document gpio-addr-flash

[Boris Brezillon]

On Wed,  3 Oct 2018 21:38:58 +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/gpio-addr-flash.txt          | 54 +++++++++++++++++++
>  1 file changed, 54 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt
> 
> diff --git a/Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt b/Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt
> new file mode 100644
> index 000000000000..5006a26e1753
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt
> @@ -0,0 +1,54 @@
> +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 : "cfi-gpio-addr-flash"
> + - reg : Address range of the mtd chip that is memory mapped, this is,
> +   on the previous example 2MiB.
> + - bank-width : Width (in bytes) of the bank.  Equal to the
> +   device width times the number of interleaved chips.
> + - gpios: List of GPIO specifiers that will be used to address the MSBs address
> +   lines. The order goes from LSB to MSB.
> + - probe-type : (optional) "cfi_probe", "jedec_probe". How the mtd chip
> +   is going to be probed. If omitted, assumed to be equal to "cfi_probe".

Looks like other bindings are encoding the probe type in the
compatible [1][2], and we should probably follow what's been done by
others.

> + - #address-cells, #size-cells : Must be present if the device has
> +   sub-nodes representing partitions (see below).  In this case
> +   both #address-cells and #size-cells must be equal to 1.
> +
> +The device tree may optionally contain sub-nodes describing partitions of the
> +address space. Check partition.txt for more details.
> +
> +Example:
> +
> +	flash@300000 {
> +		#address-cells = <1>;
> +		#size-cells = <1>;

You should not have the #address-cells and #size-cells props defined at
this level, it's done in the partitions node already.

> +		compatible = "cfi-gpio-addr-flash";
> +		bank-width = <2>;
> +		reg = < 0x00300000 0x00200000 >;
> +		gpios = <&gpio_0 3 0>, <&gpio_0 4 0>;
> +		partitions {
> +			compatible = "fixed-partitions";
> +			#address-cells = <1>;
> +			#size-cells = <1>;
> +
> +			partition@0 {
> +				reg = < 0x0 0x200000 >;
> +				label = "Golden Bitstream";
> +			};
> +			partition@200000 {
> +				reg = < 0x200000 0x200000 >;
> +				label = "User Bitstream";
> +			};
> +			partition@400000 {
> +				reg = < 0x400000 0x200000 >;
> +				label = "V4L Controls";
> +			};
> +			partition@600000 {
> +				reg = < 0x600000 0x200000 >;
> +				label = "Production Data";
> +			};
> +		}
> +	} ;

[1]https://elixir.bootlin.com/linux/latest/source/Documentation/devicetree/bindings/mtd/cortina,gemini-flash.txt
[2]https://elixir.bootlin.com/linux/latest/source/Documentation/devicetree/bindings/mtd/arm-versatile.txt

Re: [PATCH v5 7/8] dt-binding: mtd: Document gpio-addr-flash

[Ricardo Ribalda Delgado]

Hi Boris
On Wed, Oct 3, 2018 at 11:27 PM Boris Brezillon
<boris.brezillon@bootlin.com> wrote:
>
> On Wed,  3 Oct 2018 21:38:58 +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/gpio-addr-flash.txt          | 54 +++++++++++++++++++
> >  1 file changed, 54 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt
> >
> > diff --git a/Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt b/Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt
> > new file mode 100644
> > index 000000000000..5006a26e1753
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt
> > @@ -0,0 +1,54 @@
> > +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 : "cfi-gpio-addr-flash"
> > + - reg : Address range of the mtd chip that is memory mapped, this is,
> > +   on the previous example 2MiB.
> > + - bank-width : Width (in bytes) of the bank.  Equal to the
> > +   device width times the number of interleaved chips.
> > + - gpios: List of GPIO specifiers that will be used to address the MSBs address
> > +   lines. The order goes from LSB to MSB.
> > + - probe-type : (optional) "cfi_probe", "jedec_probe". How the mtd chip
> > +   is going to be probed. If omitted, assumed to be equal to "cfi_probe".
>
> Looks like other bindings are encoding the probe type in the
> compatible [1][2], and we should probably follow what's been done by
> others.

If I understood it right, they are special cases of physmap_of_core.c
https://elixir.bootlin.com/linux/v4.18.11/source/drivers/mtd/maps/physmap_of_core.c#L242

The driver that handles the compatible is physmap_of_core.c, and afaik
multiple drivers with the same
compatible string is a very bad idea.

We can convert the driver to something like Versatile or gemini, but
then we will not support platform devices

btw, the binding that I am used is used by:
https://elixir.bootlin.com/linux/v4.18.11/source/drivers/mtd/maps/physmap_of_core.c#L91

Yes, I know is obsolete

Tomorrow morning I will try to address your comments, test in hw and resend

Thanks




>
> > + - #address-cells, #size-cells : Must be present if the device has
> > +   sub-nodes representing partitions (see below).  In this case
> > +   both #address-cells and #size-cells must be equal to 1.
> > +
> > +The device tree may optionally contain sub-nodes describing partitions of the
> > +address space. Check partition.txt for more details.
> > +
> > +Example:
> > +
> > +     flash@300000 {
> > +             #address-cells = <1>;
> > +             #size-cells = <1>;
>
> You should not have the #address-cells and #size-cells props defined at
> this level, it's done in the partitions node already.
>
> > +             compatible = "cfi-gpio-addr-flash";
> > +             bank-width = <2>;
> > +             reg = < 0x00300000 0x00200000 >;
> > +             gpios = <&gpio_0 3 0>, <&gpio_0 4 0>;
> > +             partitions {
> > +                     compatible = "fixed-partitions";
> > +                     #address-cells = <1>;
> > +                     #size-cells = <1>;
> > +
> > +                     partition@0 {
> > +                             reg = < 0x0 0x200000 >;
> > +                             label = "Golden Bitstream";
> > +                     };
> > +                     partition@200000 {
> > +                             reg = < 0x200000 0x200000 >;
> > +                             label = "User Bitstream";
> > +                     };
> > +                     partition@400000 {
> > +                             reg = < 0x400000 0x200000 >;
> > +                             label = "V4L Controls";
> > +                     };
> > +                     partition@600000 {
> > +                             reg = < 0x600000 0x200000 >;
> > +                             label = "Production Data";
> > +                     };
> > +             }
> > +     } ;
>
> [1]https://elixir.bootlin.com/linux/latest/source/Documentation/devicetree/bindings/mtd/cortina,gemini-flash.txt
> [2]https://elixir.bootlin.com/linux/latest/source/Documentation/devicetree/bindings/mtd/arm-versatile.txt



-- 
Ricardo Ribalda

Re: [PATCH v5 7/8] dt-binding: mtd: Document gpio-addr-flash

[Boris Brezillon]

On Wed, 3 Oct 2018 23:53:27 +0200
Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> wrote:

> Hi Boris
> On Wed, Oct 3, 2018 at 11:27 PM Boris Brezillon
> <boris.brezillon@bootlin.com> wrote:
> >
> > On Wed,  3 Oct 2018 21:38:58 +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/gpio-addr-flash.txt          | 54 +++++++++++++++++++
> > >  1 file changed, 54 insertions(+)
> > >  create mode 100644 Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt
> > >
> > > diff --git a/Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt b/Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt
> > > new file mode 100644
> > > index 000000000000..5006a26e1753
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt
> > > @@ -0,0 +1,54 @@
> > > +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 : "cfi-gpio-addr-flash"
> > > + - reg : Address range of the mtd chip that is memory mapped, this is,
> > > +   on the previous example 2MiB.
> > > + - bank-width : Width (in bytes) of the bank.  Equal to the
> > > +   device width times the number of interleaved chips.
> > > + - gpios: List of GPIO specifiers that will be used to address the MSBs address
> > > +   lines. The order goes from LSB to MSB.
> > > + - probe-type : (optional) "cfi_probe", "jedec_probe". How the mtd chip
> > > +   is going to be probed. If omitted, assumed to be equal to "cfi_probe".  
> >
> > Looks like other bindings are encoding the probe type in the
> > compatible [1][2], and we should probably follow what's been done by
> > others.  
> 
> If I understood it right, they are special cases of physmap_of_core.c
> https://elixir.bootlin.com/linux/v4.18.11/source/drivers/mtd/maps/physmap_of_core.c#L242
> 
> The driver that handles the compatible is physmap_of_core.c, and afaik
> multiple drivers with the same
> compatible string is a very bad idea.

Yes, I know.

> 
> We can convert the driver to something like Versatile or gemini, but
> then we will not support platform devices
> 
> btw, the binding that I am used is used by:
> https://elixir.bootlin.com/linux/v4.18.11/source/drivers/mtd/maps/physmap_of_core.c#L91

Actually, the more I think about it the more I realize this should
somehow be integrated to the physmap core logic. I mean, there's nothing
controller/platform specific in what the gpio-physmap driver does.

We could basically add the msb_addr_gpios related fields to map_info,
let physmap.c and physmap_of_core.c call
devm_gpiod_get_array_optional() and, based on the returned value,
call simple_map_init() (when the pointer is NULL) or
gpio_addr_map_init() (when the pointer is valid).

gpio_addr_map_init() would still be implemented in gpio-addr-flash.c so
that we can still enable/disable support for this feature (providing
dummy wrappers when it's disabled). By doing that, we also keep a single
driver which matches a generic compatible string. We also stay
compatible with .c based board files.

Re: [PATCH v5 7/8] dt-binding: mtd: Document gpio-addr-flash

[Boris Brezillon]

On Thu, 4 Oct 2018 00:14:15 +0200
Boris Brezillon <boris.brezillon@bootlin.com> wrote:

> On Wed, 3 Oct 2018 23:53:27 +0200
> Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> wrote:
> 
> > Hi Boris
> > On Wed, Oct 3, 2018 at 11:27 PM Boris Brezillon
> > <boris.brezillon@bootlin.com> wrote:  
> > >
> > > On Wed,  3 Oct 2018 21:38:58 +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/gpio-addr-flash.txt          | 54 +++++++++++++++++++
> > > >  1 file changed, 54 insertions(+)
> > > >  create mode 100644 Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt
> > > >
> > > > diff --git a/Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt b/Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt
> > > > new file mode 100644
> > > > index 000000000000..5006a26e1753
> > > > --- /dev/null
> > > > +++ b/Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt
> > > > @@ -0,0 +1,54 @@
> > > > +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 : "cfi-gpio-addr-flash"
> > > > + - reg : Address range of the mtd chip that is memory mapped, this is,
> > > > +   on the previous example 2MiB.
> > > > + - bank-width : Width (in bytes) of the bank.  Equal to the
> > > > +   device width times the number of interleaved chips.
> > > > + - gpios: List of GPIO specifiers that will be used to address the MSBs address
> > > > +   lines. The order goes from LSB to MSB.
> > > > + - probe-type : (optional) "cfi_probe", "jedec_probe". How the mtd chip
> > > > +   is going to be probed. If omitted, assumed to be equal to "cfi_probe".    
> > >
> > > Looks like other bindings are encoding the probe type in the
> > > compatible [1][2], and we should probably follow what's been done by
> > > others.    
> > 
> > If I understood it right, they are special cases of physmap_of_core.c
> > https://elixir.bootlin.com/linux/v4.18.11/source/drivers/mtd/maps/physmap_of_core.c#L242
> > 
> > The driver that handles the compatible is physmap_of_core.c, and afaik
> > multiple drivers with the same
> > compatible string is a very bad idea.  
> 
> Yes, I know.
> 
> > 
> > We can convert the driver to something like Versatile or gemini, but
> > then we will not support platform devices
> > 
> > btw, the binding that I am used is used by:
> > https://elixir.bootlin.com/linux/v4.18.11/source/drivers/mtd/maps/physmap_of_core.c#L91  
> 
> Actually, the more I think about it the more I realize this should
> somehow be integrated to the physmap core logic. I mean, there's nothing
> controller/platform specific in what the gpio-physmap driver does.
> 
> We could basically add the msb_addr_gpios related fields to map_info,
> let physmap.c and physmap_of_core.c call
> devm_gpiod_get_array_optional() and, based on the returned value,
> call simple_map_init() (when the pointer is NULL) or
> gpio_addr_map_init() (when the pointer is valid).

Or even better, let simple_map_init() call gpio_addr_map_init() when
map->addr_gpios != NULL, so that you don't even have to duplicate the
selection logic in physmap.c and physmap_of_core.c.

> 
> gpio_addr_map_init() would still be implemented in gpio-addr-flash.c so
> that we can still enable/disable support for this feature (providing
> dummy wrappers when it's disabled). By doing that, we also keep a single
> driver which matches a generic compatible string. We also stay
> compatible with .c based board files.

Re: [PATCH v5 7/8] dt-binding: mtd: Document gpio-addr-flash

[Ricardo Ribalda Delgado]

HI Boris


On Thu, Oct 4, 2018 at 12:19 AM Boris Brezillon
<boris.brezillon@bootlin.com> wrote:
>
> On Thu, 4 Oct 2018 00:14:15 +0200
> Boris Brezillon <boris.brezillon@bootlin.com> wrote:
>
> > On Wed, 3 Oct 2018 23:53:27 +0200
> > Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> wrote:
> >
> > > Hi Boris
> > > On Wed, Oct 3, 2018 at 11:27 PM Boris Brezillon
> > > <boris.brezillon@bootlin.com> wrote:
> > > >
> > > > On Wed,  3 Oct 2018 21:38:58 +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/gpio-addr-flash.txt          | 54 +++++++++++++++++++
> > > > >  1 file changed, 54 insertions(+)
> > > > >  create mode 100644 Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt
> > > > >
> > > > > diff --git a/Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt b/Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt
> > > > > new file mode 100644
> > > > > index 000000000000..5006a26e1753
> > > > > --- /dev/null
> > > > > +++ b/Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt
> > > > > @@ -0,0 +1,54 @@
> > > > > +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 : "cfi-gpio-addr-flash"
> > > > > + - reg : Address range of the mtd chip that is memory mapped, this is,
> > > > > +   on the previous example 2MiB.
> > > > > + - bank-width : Width (in bytes) of the bank.  Equal to the
> > > > > +   device width times the number of interleaved chips.
> > > > > + - gpios: List of GPIO specifiers that will be used to address the MSBs address
> > > > > +   lines. The order goes from LSB to MSB.
> > > > > + - probe-type : (optional) "cfi_probe", "jedec_probe". How the mtd chip
> > > > > +   is going to be probed. If omitted, assumed to be equal to "cfi_probe".
> > > >
> > > > Looks like other bindings are encoding the probe type in the
> > > > compatible [1][2], and we should probably follow what's been done by
> > > > others.
> > >
> > > If I understood it right, they are special cases of physmap_of_core.c
> > > https://elixir.bootlin.com/linux/v4.18.11/source/drivers/mtd/maps/physmap_of_core.c#L242
> > >
> > > The driver that handles the compatible is physmap_of_core.c, and afaik
> > > multiple drivers with the same
> > > compatible string is a very bad idea.
> >
> > Yes, I know.
> >
> > >
> > > We can convert the driver to something like Versatile or gemini, but
> > > then we will not support platform devices
> > >
> > > btw, the binding that I am used is used by:
> > > https://elixir.bootlin.com/linux/v4.18.11/source/drivers/mtd/maps/physmap_of_core.c#L91
> >
> > Actually, the more I think about it the more I realize this should
> > somehow be integrated to the physmap core logic. I mean, there's nothing
> > controller/platform specific in what the gpio-physmap driver does.
> >
> > We could basically add the msb_addr_gpios related fields to map_info,
> > let physmap.c and physmap_of_core.c call
> > devm_gpiod_get_array_optional() and, based on the returned value,
> > call simple_map_init() (when the pointer is NULL) or
> > gpio_addr_map_init() (when the pointer is valid).
>
> Or even better, let simple_map_init() call gpio_addr_map_init() when
> map->addr_gpios != NULL, so that you don't even have to duplicate the
> selection logic in physmap.c and physmap_of_core.c.
>

I am all in for the removal of duplicated code. But I have implemented
it slightly different, following gemini and versatile

In physmap_of_core.c

I have added

err = of_flash_probe_gpio(dev, dp, &info->list[i].map);
if (err){
iounmap(info->list[i].map.virt);
goto err_out;
}

and on gpio-addr-flash the code for DT is simply

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);
}

You can take a look to the code at
https://github.com/ribalda/linux/tree/gpio-addr-flash-v6

once it is tested on hw I will commit to the list

I think now we are getting into something quite good :)

Thanks!

> >
> > gpio_addr_map_init() would still be implemented in gpio-addr-flash.c so
> > that we can still enable/disable support for this feature (providing
> > dummy wrappers when it's disabled). By doing that, we also keep a single
> > driver which matches a generic compatible string. We also stay
> > compatible with .c based board files.
>


-- 
Ricardo Ribalda