From 60a413ed5bc7917f1612df441240f458163b10c1 Mon Sep 17 00:00:00 2001
From: Hauke Mehrtens <hauke@hauke-m.de>
Date: Sat, 3 May 2014 22:54:59 +0200
Subject: [PATCH 03/15] bcm47xx-nvram: add new nvram driver with dt support

This adds a new nvrm driver which uses device tree to provide nvram
access to other drivers. You have to specify the memory ranges where
the flash chip is mapped and this driver will search there for some
nvram and parse it. Other drivers can use this driver to access the
device nvram. The nvram is used to store board configurations like the
mac address and also for configuration values in the vendor firmware.
---
 arch/mips/bcm47xx/board.c             |  36 +++---
 arch/mips/bcm47xx/nvram.c             |   7 +-
 arch/mips/bcm47xx/setup.c             |   4 +-
 arch/mips/bcm47xx/sprom.c             |   4 +-
 arch/mips/bcm47xx/time.c              |   2 +-
 drivers/misc/Kconfig                  |   5 +
 drivers/misc/Makefile                 |   1 +
 drivers/misc/bcm47xx-nvram.c          | 211 ++++++++++++++++++++++++++++++++++
 drivers/net/ethernet/broadcom/b44.c   |   2 +-
 drivers/net/ethernet/broadcom/bgmac.c |   4 +-
 drivers/ssb/driver_chipcommon_pmu.c   |   2 +-
 include/linux/bcm47xx_nvram.h         |  16 ++-
 12 files changed, 259 insertions(+), 35 deletions(-)
 create mode 100644 drivers/misc/bcm47xx-nvram.c

--- a/arch/mips/bcm47xx/board.c
+++ b/arch/mips/bcm47xx/board.c
@@ -196,50 +196,50 @@ static __init const struct bcm47xx_board
 	const struct bcm47xx_board_type_list2 *e2;
 	const struct bcm47xx_board_type_list3 *e3;
 
-	if (bcm47xx_nvram_getenv("model_name", buf1, sizeof(buf1)) >= 0) {
+	if (bcm47xx_nvram_getenv(NULL, "model_name", buf1, sizeof(buf1)) >= 0) {
 		for (e1 = bcm47xx_board_list_model_name; e1->value1; e1++) {
 			if (!strcmp(buf1, e1->value1))
 				return &e1->board;
 		}
 	}
 
-	if (bcm47xx_nvram_getenv("model_no", buf1, sizeof(buf1)) >= 0) {
+	if (bcm47xx_nvram_getenv(NULL, "model_no", buf1, sizeof(buf1)) >= 0) {
 		for (e1 = bcm47xx_board_list_model_no; e1->value1; e1++) {
 			if (strstarts(buf1, e1->value1))
 				return &e1->board;
 		}
 	}
 
-	if (bcm47xx_nvram_getenv("machine_name", buf1, sizeof(buf1)) >= 0) {
+	if (bcm47xx_nvram_getenv(NULL, "machine_name", buf1, sizeof(buf1)) >= 0) {
 		for (e1 = bcm47xx_board_list_machine_name; e1->value1; e1++) {
 			if (strstarts(buf1, e1->value1))
 				return &e1->board;
 		}
 	}
 
-	if (bcm47xx_nvram_getenv("hardware_version", buf1, sizeof(buf1)) >= 0) {
+	if (bcm47xx_nvram_getenv(NULL, "hardware_version", buf1, sizeof(buf1)) >= 0) {
 		for (e1 = bcm47xx_board_list_hardware_version; e1->value1; e1++) {
 			if (strstarts(buf1, e1->value1))
 				return &e1->board;
 		}
 	}
 
-	if (bcm47xx_nvram_getenv("productid", buf1, sizeof(buf1)) >= 0) {
+	if (bcm47xx_nvram_getenv(NULL, "productid", buf1, sizeof(buf1)) >= 0) {
 		for (e1 = bcm47xx_board_list_productid; e1->value1; e1++) {
 			if (!strcmp(buf1, e1->value1))
 				return &e1->board;
 		}
 	}
 
-	if (bcm47xx_nvram_getenv("ModelId", buf1, sizeof(buf1)) >= 0) {
+	if (bcm47xx_nvram_getenv(NULL, "ModelId", buf1, sizeof(buf1)) >= 0) {
 		for (e1 = bcm47xx_board_list_ModelId; e1->value1; e1++) {
 			if (!strcmp(buf1, e1->value1))
 				return &e1->board;
 		}
 	}
 
-	if (bcm47xx_nvram_getenv("melco_id", buf1, sizeof(buf1)) >= 0 ||
-	    bcm47xx_nvram_getenv("buf1falo_id", buf1, sizeof(buf1)) >= 0) {
+	if (bcm47xx_nvram_getenv(NULL, "melco_id", buf1, sizeof(buf1)) >= 0 ||
+	    bcm47xx_nvram_getenv(NULL, "buf1falo_id", buf1, sizeof(buf1)) >= 0) {
 		/* buffalo hardware, check id for specific hardware matches */
 		for (e1 = bcm47xx_board_list_melco_id; e1->value1; e1++) {
 			if (!strcmp(buf1, e1->value1))
@@ -247,8 +247,8 @@ static __init const struct bcm47xx_board
 		}
 	}
 
-	if (bcm47xx_nvram_getenv("boot_hw_model", buf1, sizeof(buf1)) >= 0 &&
-	    bcm47xx_nvram_getenv("boot_hw_ver", buf2, sizeof(buf2)) >= 0) {
+	if (bcm47xx_nvram_getenv(NULL, "boot_hw_model", buf1, sizeof(buf1)) >= 0 &&
+	    bcm47xx_nvram_getenv(NULL, "boot_hw_ver", buf2, sizeof(buf2)) >= 0) {
 		for (e2 = bcm47xx_board_list_boot_hw; e2->value1; e2++) {
 			if (!strcmp(buf1, e2->value1) &&
 			    !strcmp(buf2, e2->value2))
@@ -256,16 +256,16 @@ static __init const struct bcm47xx_board
 		}
 	}
 
-	if (bcm47xx_nvram_getenv("board_id", buf1, sizeof(buf1)) >= 0) {
+	if (bcm47xx_nvram_getenv(NULL, "board_id", buf1, sizeof(buf1)) >= 0) {
 		for (e1 = bcm47xx_board_list_board_id; e1->value1; e1++) {
 			if (!strcmp(buf1, e1->value1))
 				return &e1->board;
 		}
 	}
 
-	if (bcm47xx_nvram_getenv("boardtype", buf1, sizeof(buf1)) >= 0 &&
-	    bcm47xx_nvram_getenv("boardnum", buf2, sizeof(buf2)) >= 0 &&
-	    bcm47xx_nvram_getenv("boardrev", buf3, sizeof(buf3)) >= 0) {
+	if (bcm47xx_nvram_getenv(NULL, "boardtype", buf1, sizeof(buf1)) >= 0 &&
+	    bcm47xx_nvram_getenv(NULL, "boardnum", buf2, sizeof(buf2)) >= 0 &&
+	    bcm47xx_nvram_getenv(NULL, "boardrev", buf3, sizeof(buf3)) >= 0) {
 		for (e3 = bcm47xx_board_list_board; e3->value1; e3++) {
 			if (!strcmp(buf1, e3->value1) &&
 			    !strcmp(buf2, e3->value2) &&
@@ -286,7 +286,7 @@ void __init bcm47xx_board_detect(void)
 		return;
 
 	/* check if the nvram is available */
-	err = bcm47xx_nvram_getenv("boardtype", buf, sizeof(buf));
+	err = bcm47xx_nvram_getenv(NULL, "boardtype", buf, sizeof(buf));
 
 	/* init of nvram failed, probably too early now */
 	if (err == -ENXIO) {
--- a/arch/mips/bcm47xx/nvram.c
+++ b/arch/mips/bcm47xx/nvram.c
@@ -158,7 +158,8 @@ static int nvram_init(void)
 	return -ENXIO;
 }
 
-int bcm47xx_nvram_getenv(char *name, char *val, size_t val_len)
+int bcm47xx_nvram_getenv(const struct device *dev, const char *name, char *val,
+			 size_t val_len)
 {
 	char *var, *value, *end, *eq;
 	int err;
@@ -190,7 +191,7 @@ int bcm47xx_nvram_getenv(char *name, cha
 }
 EXPORT_SYMBOL(bcm47xx_nvram_getenv);
 
-int bcm47xx_nvram_gpio_pin(const char *name)
+int bcm47xx_nvram_gpio_pin(const struct device *dev, const char *name)
 {
 	int i, err;
 	char nvram_var[10];
@@ -200,7 +201,7 @@ int bcm47xx_nvram_gpio_pin(const char *n
 		err = snprintf(nvram_var, sizeof(nvram_var), "gpio%i", i);
 		if (err <= 0)
 			continue;
-		err = bcm47xx_nvram_getenv(nvram_var, buf, sizeof(buf));
+		err = bcm47xx_nvram_getenv(dev, nvram_var, buf, sizeof(buf));
 		if (err <= 0)
 			continue;
 		if (!strcmp(name, buf))
--- a/arch/mips/bcm47xx/setup.c
+++ b/arch/mips/bcm47xx/setup.c
@@ -123,7 +123,7 @@ static int bcm47xx_get_invariants(struct
 	memset(&iv->sprom, 0, sizeof(struct ssb_sprom));
 	bcm47xx_fill_sprom(&iv->sprom, NULL, false);
 
-	if (bcm47xx_nvram_getenv("cardbus", buf, sizeof(buf)) >= 0)
+	if (bcm47xx_nvram_getenv(NULL, "cardbus", buf, sizeof(buf)) >= 0)
 		iv->has_cardbus_slot = !!simple_strtoul(buf, NULL, 10);
 
 	return 0;
@@ -146,7 +146,7 @@ static void __init bcm47xx_register_ssb(
 		panic("Failed to initialize SSB bus (err %d)", err);
 
 	mcore = &bcm47xx_bus.ssb.mipscore;
-	if (bcm47xx_nvram_getenv("kernel_args", buf, sizeof(buf)) >= 0) {
+	if (bcm47xx_nvram_getenv(NULL, "kernel_args", buf, sizeof(buf)) >= 0) {
 		if (strstr(buf, "console=ttyS1")) {
 			struct ssb_serial_port port;
 
--- a/arch/mips/bcm47xx/sprom.c
+++ b/arch/mips/bcm47xx/sprom.c
@@ -50,10 +50,10 @@ static int get_nvram_var(const char *pre
 
 	create_key(prefix, postfix, name, key, sizeof(key));
 
-	err = bcm47xx_nvram_getenv(key, buf, len);
+	err = bcm47xx_nvram_getenv(NULL, key, buf, len);
 	if (fallback && err == -ENOENT && prefix) {
 		create_key(NULL, postfix, name, key, sizeof(key));
-		err = bcm47xx_nvram_getenv(key, buf, len);
+		err = bcm47xx_nvram_getenv(NULL, key, buf, len);
 	}
 	return err;
 }
--- a/arch/mips/bcm47xx/time.c
+++ b/arch/mips/bcm47xx/time.c
@@ -61,7 +61,7 @@ void __init plat_time_init(void)
 	}
 
 	if (chip_id == 0x5354) {
-		len = bcm47xx_nvram_getenv("clkfreq", buf, sizeof(buf));
+		len = bcm47xx_nvram_getenv(NULL, "clkfreq", buf, sizeof(buf));
 		if (len >= 0 && !strncmp(buf, "200", 4))
 			hz = 100000000;
 	}
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -515,6 +515,11 @@ config SRAM
 	  the genalloc API. It is supposed to be used for small on-chip SRAM
 	  areas found on many SoCs.
 
+config BCM47XX_NVRAM
+	tristate "BCM47XX nvram driver"
+	help
+		This adds support for the brcm47xx nvram driver.
+
 source "drivers/misc/c2port/Kconfig"
 source "drivers/misc/eeprom/Kconfig"
 source "drivers/misc/cb710/Kconfig"
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -54,3 +54,4 @@ obj-$(CONFIG_LATTICE_ECP3_CONFIG)	+= lat
 obj-$(CONFIG_SRAM)		+= sram.o
 obj-y				+= mic/
 obj-$(CONFIG_GENWQE)		+= genwqe/
+obj-$(CONFIG_BCM47XX_NVRAM)	+= bcm47xx-nvram.o
--- /dev/null
+++ b/drivers/misc/bcm47xx-nvram.c
@@ -0,0 +1,211 @@
+/*
+ * BCM947xx nvram variable access
+ *
+ * Copyright (C) 2005 Broadcom Corporation
+ * Copyright (C) 2006 Felix Fietkau <nbd@openwrt.org>
+ * Copyright (C) 2010-2014 Hauke Mehrtens <hauke@hauke-m.de>
+ *
+ * This program is free software; you can redistribute	it and/or modify it
+ * under  the terms of	the GNU General	 Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/of_address.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/bcm47xx_nvram.h>
+
+struct bcm47xx_nvram {
+	size_t nvram_len;
+	char *nvram_buf;
+};
+
+static const u32 nvram_sizes[] = {0x8000, 0xF000, 0x10000};
+
+static u32 find_nvram_size(void __iomem *end)
+{
+	struct nvram_header *header;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(nvram_sizes); i++) {
+		header = (struct nvram_header *)(end - nvram_sizes[i]);
+		if (header->magic == NVRAM_HEADER)
+			return nvram_sizes[i];
+	}
+
+	return 0;
+}
+
+/* Probe for NVRAM header */
+static int nvram_find_and_copy(struct device *dev, void __iomem *base,
+			       size_t len, char **nvram_buf,
+			       size_t *nvram_len)
+{
+	struct nvram_header *header;
+	int i;
+	u32 off;
+	u32 *src, *dst;
+	u32 size;
+
+	/* TODO: when nvram is on nand flash check for bad blocks first. */
+	off = FLASH_MIN;
+	while (off <= len) {
+		/* Windowed flash access */
+		size = find_nvram_size(base + off);
+		if (size) {
+			header = (struct nvram_header *)(base + off - size);
+			goto found;
+		}
+		off <<= 1;
+	}
+
+	/* Try embedded NVRAM at 4 KB and 1 KB as last resorts */
+	header = (struct nvram_header *)(base + 4096);
+	if (header->magic == NVRAM_HEADER) {
+		size = NVRAM_SPACE;
+		goto found;
+	}
+
+	header = (struct nvram_header *)(base + 1024);
+	if (header->magic == NVRAM_HEADER) {
+		size = NVRAM_SPACE;
+		goto found;
+	}
+
+	*nvram_buf = NULL;
+	*nvram_len = 0;
+	pr_err("no nvram found\n");
+	return -ENXIO;
+
+found:
+	if (header->len > size)
+		pr_err("The nvram size accoridng to the header seems to be bigger than the partition on flash\n");
+	*nvram_len = min_t(u32, header->len, size);
+
+	*nvram_buf = devm_kzalloc(dev, *nvram_len, GFP_KERNEL);
+	if (!*nvram_buf)
+		return -ENOMEM;
+
+	src = (u32 *) header;
+	dst = (u32 *) *nvram_buf;
+	for (i = 0; i < sizeof(struct nvram_header); i += 4)
+		*dst++ = *src++;
+	for (; i < *nvram_len; i += 4)
+		*dst++ = le32_to_cpu(*src++);
+
+	return 0;
+}
+
+int bcm47xx_nvram_getenv(const struct device *dev, const char *name, char *val, size_t val_len)
+{
+	char *var, *value, *end, *eq;
+	struct bcm47xx_nvram *nvram;
+
+	if (!dev)
+		return -ENODEV;
+
+	nvram = dev_get_drvdata(dev);
+
+	if (!name || !nvram || !nvram->nvram_len)
+		return -EINVAL;
+
+	/* Look for name=value and return value */
+	var = nvram->nvram_buf + sizeof(struct nvram_header);
+	end = nvram->nvram_buf + nvram->nvram_len - 2;
+	end[0] = end[1] = '\0';
+	for (; *var; var = value + strlen(value) + 1) {
+		eq = strchr(var, '=');
+		if (!eq)
+			break;
+		value = eq + 1;
+		if ((eq - var) == strlen(name) &&
+			strncmp(var, name, (eq - var)) == 0) {
+			return snprintf(val, val_len, "%s", value);
+		}
+	}
+	return -ENOENT;
+}
+EXPORT_SYMBOL(bcm47xx_nvram_getenv);
+
+int bcm47xx_nvram_gpio_pin(const struct device *dev, const char *name)
+{
+	int i, err;
+	char nvram_var[10];
+	char buf[30];
+
+	if (!dev)
+		return -ENODEV;
+
+	for (i = 0; i < 32; i++) {
+		err = snprintf(nvram_var, sizeof(nvram_var), "gpio%i", i);
+		if (err <= 0)
+			continue;
+		err = bcm47xx_nvram_getenv(dev, nvram_var, buf, sizeof(buf));
+		if (err <= 0)
+			continue;
+		if (!strcmp(name, buf))
+			return i;
+	}
+	return -ENOENT;
+}
+EXPORT_SYMBOL(bcm47xx_nvram_gpio_pin);
+
+static int bcm47xx_nvram_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct bcm47xx_nvram *nvram;
+	int err;
+	struct resource flash_mem;
+	void __iomem *mmio;
+
+	/* Alloc */
+	nvram = devm_kzalloc(dev, sizeof(*nvram), GFP_KERNEL);
+	if (!nvram)
+		return -ENOMEM;
+
+	err = of_address_to_resource(np, 0, &flash_mem);
+	if (err)
+		return err;
+
+	mmio = ioremap_nocache(flash_mem.start, resource_size(&flash_mem));
+	if (!mmio)
+		return -ENOMEM;
+
+	err = nvram_find_and_copy(dev, mmio, resource_size(&flash_mem), &nvram->nvram_buf, &nvram->nvram_len);
+	if (err)
+		goto err_unmap_mmio;
+
+	platform_set_drvdata(pdev, nvram);
+
+err_unmap_mmio:
+	iounmap(mmio);
+	return err;
+}
+
+static const struct of_device_id bcm47xx_nvram_of_match_table[] = {
+	{ .compatible = "brcm,bcm47xx-nvram", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, mvebu_pcie_of_match_table);
+
+static struct platform_driver bcm47xx_nvram_driver = {
+	.driver = {
+		.owner = THIS_MODULE,
+		.name = "bcm47xx-nvram",
+		.of_match_table = bcm47xx_nvram_of_match_table,
+		/* driver unloading/unbinding currently not supported */
+		.suppress_bind_attrs = true,
+	},
+	.probe = bcm47xx_nvram_probe,
+};
+module_platform_driver(bcm47xx_nvram_driver);
+
+MODULE_AUTHOR("Hauke Mehrtens <hauke@hauke-m.de>");
+MODULE_LICENSE("GPLv2");
--- a/drivers/net/ethernet/broadcom/b44.c
+++ b/drivers/net/ethernet/broadcom/b44.c
@@ -411,7 +411,7 @@ static void b44_wap54g10_workaround(stru
 	 * see https://dev.openwrt.org/ticket/146
 	 * check and reset bit "isolate"
 	 */
-	if (bcm47xx_nvram_getenv("boardnum", buf, sizeof(buf)) < 0)
+	if (bcm47xx_nvram_getenv(NULL, "boardnum", buf, sizeof(buf)) < 0)
 		return;
 	if (simple_strtoul(buf, NULL, 0) == 2) {
 		err = __b44_readphy(bp, 0, MII_BMCR, &val);
--- a/drivers/net/ethernet/broadcom/bgmac.c
+++ b/drivers/net/ethernet/broadcom/bgmac.c
@@ -974,7 +974,7 @@ static void bgmac_chip_reset(struct bgma
 			     BGMAC_CHIPCTL_1_IF_TYPE_MII;
 		char buf[4];
 
-		if (bcm47xx_nvram_getenv("et_swtype", buf, sizeof(buf)) > 0) {
+		if (bcm47xx_nvram_getenv(NULL, "et_swtype", buf, sizeof(buf)) > 0) {
 			if (kstrtou8(buf, 0, &et_swtype))
 				bgmac_err(bgmac, "Failed to parse et_swtype (%s)\n",
 					  buf);
@@ -1534,7 +1534,7 @@ static int bgmac_probe(struct bcma_devic
 	}
 
 	bgmac->int_mask = BGMAC_IS_ERRMASK | BGMAC_IS_RX | BGMAC_IS_TX_MASK;
-	if (bcm47xx_nvram_getenv("et0_no_txint", NULL, 0) == 0)
+	if (bcm47xx_nvram_getenv(NULL, "et0_no_txint", NULL, 0) == 0)
 		bgmac->int_mask &= ~BGMAC_IS_TX_MASK;
 
 	/* TODO: reset the external phy. Specs are needed */
--- a/drivers/ssb/driver_chipcommon_pmu.c
+++ b/drivers/ssb/driver_chipcommon_pmu.c
@@ -319,7 +319,7 @@ static void ssb_pmu_pll_init(struct ssb_
 
 	if (bus->bustype == SSB_BUSTYPE_SSB) {
 		char buf[20];
-		if (bcm47xx_nvram_getenv("xtalfreq", buf, sizeof(buf)) >= 0)
+		if (bcm47xx_nvram_getenv(NULL, "xtalfreq", buf, sizeof(buf)) >= 0)
 			crystalfreq = simple_strtoul(buf, NULL, 0);
 	}
 
--- a/include/linux/bcm47xx_nvram.h
+++ b/include/linux/bcm47xx_nvram.h
@@ -15,6 +15,8 @@
 #include <linux/types.h>
 #include <linux/kernel.h>
 
+struct device;
+
 struct nvram_header {
 	u32 magic;
 	u32 len;
@@ -33,17 +35,21 @@ struct nvram_header {
 #define NVRAM_MAX_VALUE_LEN 255
 #define NVRAM_MAX_PARAM_LEN 64
 
-#ifdef CONFIG_BCM47XX
-int bcm47xx_nvram_getenv(const char *name, char *val, size_t val_len);
+#if defined(CONFIG_BCM47XX) || defined(CONFIG_BCM47XX_NVRAM)
+int bcm47xx_nvram_getenv(const struct device *dev, const char *name, char *val,
+			 size_t val_len);
 
-int bcm47xx_nvram_gpio_pin(const char *name);
+int bcm47xx_nvram_gpio_pin(const struct device *dev, const char *name);
 #else
-static inline int bcm47xx_nvram_getenv(const char *name, char *val, size_t val_len)
+static inline int bcm47xx_nvram_getenv(const struct device *dev,
+				       const char *name, char *val,
+				       size_t val_len)
 {
 	return -ENXIO;
 }
 
-static inline int bcm47xx_nvram_gpio_pin(const char *name)
+static inline int bcm47xx_nvram_gpio_pin(const struct device *dev,
+					 const char *name)
 {
 	return -ENXIO;
 }