1 // SPDX-License-Identifier: GPL-2.0
3 * Cortina Systems Gemini OF physmap add-on
4 * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
6 * This SoC has an elaborate flash control register, so we need to
7 * detect and set it up when booting on this platform.
9 #include <linux/export.h>
11 #include <linux/of_device.h>
12 #include <linux/mtd/map.h>
13 #include <linux/mfd/syscon.h>
14 #include <linux/regmap.h>
15 #include <linux/bitops.h>
16 #include "physmap_of_gemini.h"
19 * The Flash-relevant parts of the global status register
20 * These would also be relevant for a NAND driver.
22 #define GLOBAL_STATUS 0x04
23 #define FLASH_TYPE_MASK (0x3 << 24)
24 #define FLASH_TYPE_NAND_2K (0x3 << 24)
25 #define FLASH_TYPE_NAND_512 (0x2 << 24)
26 #define FLASH_TYPE_PARALLEL (0x1 << 24)
27 #define FLASH_TYPE_SERIAL (0x0 << 24)
29 #define FLASH_WIDTH_16BIT (1 << 23) /* else 8 bit */
31 #define FLASH_ATMEL (1 << 23) /* else STM */
33 #define FLASH_SIZE_MASK (0x3 << 21)
34 #define NAND_256M (0x3 << 21) /* and more */
35 #define NAND_128M (0x2 << 21)
36 #define NAND_64M (0x1 << 21)
37 #define NAND_32M (0x0 << 21)
38 #define ATMEL_16M (0x3 << 21) /* and more */
39 #define ATMEL_8M (0x2 << 21)
40 #define ATMEL_4M_2M (0x1 << 21)
41 #define ATMEL_1M (0x0 << 21) /* and less */
42 #define STM_32M (1 << 22) /* and more */
43 #define STM_16M (0 << 22) /* and less */
45 #define FLASH_PARALLEL_HIGH_PIN_CNT (1 << 20) /* else low pin cnt */
47 int of_flash_probe_gemini(struct platform_device *pdev,
48 struct device_node *np,
52 struct device *dev = &pdev->dev;
56 /* Multiplatform guard */
57 if (!of_device_is_compatible(np, "cortina,gemini-flash"))
60 rmap = syscon_regmap_lookup_by_phandle(np, "syscon");
62 dev_err(dev, "no syscon\n");
66 ret = regmap_read(rmap, GLOBAL_STATUS, &val);
68 dev_err(dev, "failed to read global status register\n");
71 dev_dbg(dev, "global status reg: %08x\n", val);
74 * It would be contradictory if a physmap flash was NOT parallel.
76 if ((val & FLASH_TYPE_MASK) != FLASH_TYPE_PARALLEL) {
77 dev_err(dev, "flash is not parallel\n");
82 * Complain if DT data and hardware definition is different.
84 if (val & FLASH_WIDTH_16BIT) {
85 if (map->bankwidth != 2)
86 dev_warn(dev, "flash hardware say flash is 16 bit wide but DT says it is %d bits wide\n",
89 if (map->bankwidth != 1)
90 dev_warn(dev, "flash hardware say flash is 8 bit wide but DT says it is %d bits wide\n",
94 dev_info(&pdev->dev, "initialized Gemini-specific physmap control\n");