taken from OF device tree.
config MTD_PHYSMAP_OF_VERSATILE
- bool "Support ARM Versatile physmap OF"
+ bool "ARM Versatile OF-based physical memory map handling"
depends on MTD_PHYSMAP_OF
depends on MFD_SYSCON
default y if (ARCH_INTEGRATOR || ARCH_VERSATILE || ARCH_REALVIEW)
platforms, basically to add a VPP (write protection) callback so
the flash can be taken out of write protection.
+config MTD_PHYSMAP_OF_GEMINI
+ bool "Cortina Gemini OF-based physical memory map handling"
+ depends on MTD_PHYSMAP_OF
+ depends on MFD_SYSCON
+ default ARCH_GEMINI
+ help
+ This provides some extra DT physmap parsing for the Gemini
+ platforms, some detection and setting up parallel mode on the
+ external interface.
+
config MTD_PMC_MSP_EVM
tristate "CFI Flash device mapped on PMC-Sierra MSP"
depends on PMC_MSP && MTD_CFI
--- /dev/null
+/*
+ * 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/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/bitops.h>
+#include "physmap_of_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 */
+
+/* Miscellaneous Control Register */
+#define GLOBAL_MISC_CTRL 0x30
+#define FLASH_PADS_MASK 0x07
+#define NAND_PADS_DISABLE BIT(2)
+#define PFLASH_PADS_DISABLE BIT(1)
+#define SFLASH_PADS_DISABLE BIT(0)
+
+static const struct of_device_id syscon_match[] = {
+ { .compatible = "cortina,gemini-syscon" },
+ { },
+};
+
+int of_flash_probe_gemini(struct platform_device *pdev,
+ struct device_node *np,
+ struct map_info *map)
+{
+ static 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;
+
+ 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);
+ }
+
+ /* Activate parallel (NOR flash) mode */
+ ret = regmap_update_bits(rmap, GLOBAL_MISC_CTRL,
+ FLASH_PADS_MASK,
+ SFLASH_PADS_DISABLE | NAND_PADS_DISABLE);
+ if (ret) {
+ dev_err(dev, "unable to set up physmap pads\n");
+ return -ENODEV;
+ }
+
+ dev_info(&pdev->dev, "initialized Gemini-specific physmap control\n");
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(of_flash_probe_gemini);
projects / karo-tx-linux.git / commitdiff