@@ -89,6 +89,7 @@ config MTD_PHYSMAP_OF_GEMINI
depends on MTD_PHYSMAP_OF
depends on MFD_SYSCON
default ARCH_GEMINI
+ select MTD_COMPLEX_MAPPINGS
help
This provides some extra DT physmap parsing for the Gemini
platforms, some detection and setting up parallel mode on the
@@ -10,9 +10,11 @@
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/mtd/map.h>
+#include <linux/mtd/xip.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
#include <linux/bitops.h>
+#include <linux/pinctrl/consumer.h>
#include "physmap_of_gemini.h"
/*
@@ -49,6 +51,77 @@ static const struct of_device_id syscon_match[] = {
{ },
};
+struct gemini_flash {
+ struct device *dev;
+ struct pinctrl *p;
+ struct pinctrl_state *enabled_state;
+ struct pinctrl_state *disabled_state;
+};
+
+/* Static local state */
+static struct gemini_flash *gf;
+
+static void gemini_flash_enable_pins(void)
+{
+ int ret;
+
+ if (IS_ERR(gf->enabled_state))
+ return;
+ ret = pinctrl_select_state(gf->p, gf->enabled_state);
+ if (ret)
+ dev_err(gf->dev, "failed to enable pins\n");
+}
+
+static void gemini_flash_disable_pins(void)
+{
+ int ret;
+
+ if (IS_ERR(gf->disabled_state))
+ return;
+ ret = pinctrl_select_state(gf->p, gf->disabled_state);
+ if (ret)
+ dev_err(gf->dev, "failed to disable pins\n");
+}
+
+static map_word __xipram gemini_flash_map_read(struct map_info *map,
+ unsigned long ofs)
+{
+ map_word __xipram ret;
+
+ gemini_flash_enable_pins();
+ ret = inline_map_read(map, ofs);
+ gemini_flash_disable_pins();
+
+ return ret;
+}
+
+static void __xipram gemini_flash_map_write(struct map_info *map,
+ const map_word datum,
+ unsigned long ofs)
+{
+ gemini_flash_enable_pins();
+ inline_map_write(map, datum, ofs);
+ gemini_flash_disable_pins();
+}
+
+static void __xipram gemini_flash_map_copy_from(struct map_info *map,
+ void *to, unsigned long from,
+ ssize_t len)
+{
+ gemini_flash_enable_pins();
+ inline_map_copy_from(map, to, from, len);
+ gemini_flash_disable_pins();
+}
+
+static void __xipram gemini_flash_map_copy_to(struct map_info *map,
+ unsigned long to,
+ const void *from, ssize_t len)
+{
+ gemini_flash_enable_pins();
+ inline_map_copy_to(map, to, from, len);
+ gemini_flash_disable_pins();
+}
+
int of_flash_probe_gemini(struct platform_device *pdev,
struct device_node *np,
struct map_info *map)
@@ -62,6 +135,11 @@ int of_flash_probe_gemini(struct platform_device *pdev,
if (!of_device_is_compatible(np, "cortina,gemini-flash"))
return 0;
+ gf = devm_kzalloc(dev, sizeof(*gf), GFP_KERNEL);
+ if (!gf)
+ return -ENOMEM;
+ gf->dev = dev;
+
rmap = syscon_regmap_lookup_by_phandle(np, "syscon");
if (IS_ERR(rmap)) {
dev_err(dev, "no syscon\n");
@@ -96,7 +174,32 @@ int of_flash_probe_gemini(struct platform_device *pdev,
map->bankwidth * 8);
}
- dev_info(&pdev->dev, "initialized Gemini-specific physmap control\n");
+ gf->p = devm_pinctrl_get(dev);
+ if (IS_ERR(gf->p)) {
+ dev_err(dev, "no pinctrl handle\n");
+ ret = PTR_ERR(gf->p);
+ return ret;
+ }
+
+ gf->enabled_state = pinctrl_lookup_state(gf->p, "enabled");
+ if (IS_ERR(gf->enabled_state))
+ dev_err(dev, "no enabled pin control state\n");
+
+ gf->disabled_state = pinctrl_lookup_state(gf->p, "disabled");
+ if (IS_ERR(gf->enabled_state)) {
+ dev_err(dev, "no disabled pin control state\n");
+ } else {
+ ret = pinctrl_select_state(gf->p, gf->disabled_state);
+ if (ret)
+ dev_err(gf->dev, "failed to disable pins\n");
+ }
+
+ map->read = gemini_flash_map_read;
+ map->write = gemini_flash_map_write;
+ map->copy_from = gemini_flash_map_copy_from;
+ map->copy_to = gemini_flash_map_copy_to;
+
+ dev_info(dev, "initialized Gemini-specific physmap control\n");
return 0;
}
This enables the complex mapping for the Gemini and kicks in custom read/write functions that will wrap the existing simple functions in calls to enable/disable the parallel flash pins using pin controls. This is necessary on some hardware such as the D-Link DIR-685 where all flash pins are patched in/out at the same time, but some of the flash pins are in practice unused by the flash and have anyway been reused as GPIO. This concerns specifically CE1 on the Gemini. There is only one flash chip, so only CE0 is used, and the line for CE1 has been reused as chip select for the emulated SPI port connected to the display. If we try to use the same lines for flash and GPIO at the same time, one of them will loose: the GPIO line will disappear because it gets disconnected from the pin when the flash group is muxed out. Fix this by introducing two pin control states named simply "enabled" and "disabled" and only enable the flash lines when absolutely necessary (during read/write/copy). This way, they are available for GPIO at all other times and the display works. Collect all the state variables in a struct named struct gemini_flash and allocate this struct at probe time. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> --- drivers/mtd/maps/Kconfig | 1 + drivers/mtd/maps/physmap_of_gemini.c | 105 ++++++++++++++++++++++++++- 2 files changed, 105 insertions(+), 1 deletion(-) -- 2.17.1 ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/