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-rw-r--r--drivers/mtd/maps/physmap-gemini.c200
1 files changed, 200 insertions, 0 deletions
diff --git a/drivers/mtd/maps/physmap-gemini.c b/drivers/mtd/maps/physmap-gemini.c
new file mode 100644
index 000000000..d4a46e159
--- /dev/null
+++ b/drivers/mtd/maps/physmap-gemini.c
@@ -0,0 +1,200 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Cortina Systems Gemini OF physmap add-on
+ * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
+ *
+ * This SoC has an elaborate flash control register, so we need to
+ * detect and set it up when booting on this platform.
+ */
+#include <linux/export.h>
+#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-gemini.h"
+
+/*
+ * The Flash-relevant parts of the global status register
+ * These would also be relevant for a NAND driver.
+ */
+#define GLOBAL_STATUS 0x04
+#define FLASH_TYPE_MASK (0x3 << 24)
+#define FLASH_TYPE_NAND_2K (0x3 << 24)
+#define FLASH_TYPE_NAND_512 (0x2 << 24)
+#define FLASH_TYPE_PARALLEL (0x1 << 24)
+#define FLASH_TYPE_SERIAL (0x0 << 24)
+/* if parallel */
+#define FLASH_WIDTH_16BIT (1 << 23) /* else 8 bit */
+/* if serial */
+#define FLASH_ATMEL (1 << 23) /* else STM */
+
+#define FLASH_SIZE_MASK (0x3 << 21)
+#define NAND_256M (0x3 << 21) /* and more */
+#define NAND_128M (0x2 << 21)
+#define NAND_64M (0x1 << 21)
+#define NAND_32M (0x0 << 21)
+#define ATMEL_16M (0x3 << 21) /* and more */
+#define ATMEL_8M (0x2 << 21)
+#define ATMEL_4M_2M (0x1 << 21)
+#define ATMEL_1M (0x0 << 21) /* and less */
+#define STM_32M (1 << 22) /* and more */
+#define STM_16M (0 << 22) /* and less */
+
+#define FLASH_PARALLEL_HIGH_PIN_CNT (1 << 20) /* else low pin cnt */
+
+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 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)
+{
+ struct regmap *rmap;
+ struct device *dev = &pdev->dev;
+ u32 val;
+ int ret;
+
+ /* Multiplatform guard */
+ 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");
+ return PTR_ERR(rmap);
+ }
+
+ ret = regmap_read(rmap, GLOBAL_STATUS, &val);
+ if (ret) {
+ dev_err(dev, "failed to read global status register\n");
+ return -ENODEV;
+ }
+ dev_dbg(dev, "global status reg: %08x\n", val);
+
+ /*
+ * It would be contradictory if a physmap flash was NOT parallel.
+ */
+ if ((val & FLASH_TYPE_MASK) != FLASH_TYPE_PARALLEL) {
+ dev_err(dev, "flash is not parallel\n");
+ return -ENODEV;
+ }
+
+ /*
+ * Complain if DT data and hardware definition is different.
+ */
+ if (val & FLASH_WIDTH_16BIT) {
+ if (map->bankwidth != 2)
+ dev_warn(dev, "flash hardware say flash is 16 bit wide but DT says it is %d bits wide\n",
+ map->bankwidth * 8);
+ } else {
+ if (map->bankwidth != 1)
+ dev_warn(dev, "flash hardware say flash is 8 bit wide but DT says it is %d bits wide\n",
+ map->bankwidth * 8);
+ }
+
+ 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;
+}