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Diffstat (limited to '')
| -rw-r--r-- | drivers/mtd/maps/physmap-gemini.c | 200 |
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; +} |