Use preferred print methods dev_*
Signed-off-by: Ricardo Ribalda Delgado <[email protected]>
---
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
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 <[email protected]>
Fixes: ebd71e3a4861 ("mtd: maps: gpio-addr-flash: fix warnings and make more portable")
Cc: <[email protected]>
---
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
Add documentation for gpio-addr-flash. This binding allow creating
flash devices that are paged using GPIOs.
Cc: [email protected]
Reviewed-by: Rob Herring <[email protected]>
Signed-off-by: Ricardo Ribalda Delgado <[email protected]>
---
.../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
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 <[email protected]>
---
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 <[email protected]>
* Copyright © 2005-2009 Analog Devices Inc.
+ * Copyright © 2018 Ricardo Ribalda <[email protected]>
*
* 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
Convert from legacy gpio API to gpiod.
Board files will have to use gpiod_lookup_tables.
Signed-off-by: Ricardo Ribalda Delgado <[email protected]>
Suggested-by: Boris Brezillon <[email protected]>
---
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
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 <[email protected]>
---
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
By using devm functions we can make the code cleaner.
Signed-off-by: Ricardo Ribalda Delgado <[email protected]>
---
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
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 <[email protected]>
---
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
On Wed, 3 Oct 2018 21:38:58 +0200
Ricardo Ribalda Delgado <[email protected]> wrote:
> Add documentation for gpio-addr-flash. This binding allow creating
> flash devices that are paged using GPIOs.
>
> Cc: [email protected]
> Reviewed-by: Rob Herring <[email protected]>
> Signed-off-by: Ricardo Ribalda Delgado <[email protected]>
> ---
> .../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";
> + };
> + }
> + } ;
On Wed, 3 Oct 2018 21:38:59 +0200
Ricardo Ribalda Delgado <[email protected]> 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 <[email protected]>
> ---
> 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 <[email protected]>
> * Copyright © 2005-2009 Analog Devices Inc.
> + * Copyright © 2018 Ricardo Ribalda <[email protected]>
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.
On Wed, 3 Oct 2018 21:38:58 +0200
Ricardo Ribalda Delgado <[email protected]> wrote:
> Add documentation for gpio-addr-flash. This binding allow creating
> flash devices that are paged using GPIOs.
>
> Cc: [email protected]
> Reviewed-by: Rob Herring <[email protected]>
> Signed-off-by: Ricardo Ribalda Delgado <[email protected]>
> ---
> .../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
Hi Boris
On Wed, Oct 3, 2018 at 11:27 PM Boris Brezillon
<[email protected]> wrote:
>
> On Wed, 3 Oct 2018 21:38:58 +0200
> Ricardo Ribalda Delgado <[email protected]> wrote:
>
> > Add documentation for gpio-addr-flash. This binding allow creating
> > flash devices that are paged using GPIOs.
> >
> > Cc: [email protected]
> > Reviewed-by: Rob Herring <[email protected]>
> > Signed-off-by: Ricardo Ribalda Delgado <[email protected]>
> > ---
> > .../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
On Wed, 3 Oct 2018 23:53:27 +0200
Ricardo Ribalda Delgado <[email protected]> wrote:
> Hi Boris
> On Wed, Oct 3, 2018 at 11:27 PM Boris Brezillon
> <[email protected]> wrote:
> >
> > On Wed, 3 Oct 2018 21:38:58 +0200
> > Ricardo Ribalda Delgado <[email protected]> wrote:
> >
> > > Add documentation for gpio-addr-flash. This binding allow creating
> > > flash devices that are paged using GPIOs.
> > >
> > > Cc: [email protected]
> > > Reviewed-by: Rob Herring <[email protected]>
> > > Signed-off-by: Ricardo Ribalda Delgado <[email protected]>
> > > ---
> > > .../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.
On Thu, 4 Oct 2018 00:14:15 +0200
Boris Brezillon <[email protected]> wrote:
> On Wed, 3 Oct 2018 23:53:27 +0200
> Ricardo Ribalda Delgado <[email protected]> wrote:
>
> > Hi Boris
> > On Wed, Oct 3, 2018 at 11:27 PM Boris Brezillon
> > <[email protected]> wrote:
> > >
> > > On Wed, 3 Oct 2018 21:38:58 +0200
> > > Ricardo Ribalda Delgado <[email protected]> wrote:
> > >
> > > > Add documentation for gpio-addr-flash. This binding allow creating
> > > > flash devices that are paged using GPIOs.
> > > >
> > > > Cc: [email protected]
> > > > Reviewed-by: Rob Herring <[email protected]>
> > > > Signed-off-by: Ricardo Ribalda Delgado <[email protected]>
> > > > ---
> > > > .../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.
HI Boris
On Thu, Oct 4, 2018 at 12:19 AM Boris Brezillon
<[email protected]> wrote:
>
> On Thu, 4 Oct 2018 00:14:15 +0200
> Boris Brezillon <[email protected]> wrote:
>
> > On Wed, 3 Oct 2018 23:53:27 +0200
> > Ricardo Ribalda Delgado <[email protected]> wrote:
> >
> > > Hi Boris
> > > On Wed, Oct 3, 2018 at 11:27 PM Boris Brezillon
> > > <[email protected]> wrote:
> > > >
> > > > On Wed, 3 Oct 2018 21:38:58 +0200
> > > > Ricardo Ribalda Delgado <[email protected]> wrote:
> > > >
> > > > > Add documentation for gpio-addr-flash. This binding allow creating
> > > > > flash devices that are paged using GPIOs.
> > > > >
> > > > > Cc: [email protected]
> > > > > Reviewed-by: Rob Herring <[email protected]>
> > > > > Signed-off-by: Ricardo Ribalda Delgado <[email protected]>
> > > > > ---
> > > > > .../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