blob: 9d3b4bf84a1ad7cb340d916b39a281b46af8dc33 [file] [log] [blame]
// 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/mtd/map.h>
#include <linux/mtd/xip.h>
#include <linux/mfd/syscon.h>
#include <linux/platform_device.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;
}