Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 288 insertions, 0 deletions

diff --git a/drivers/nvmem/lpc18xx_eeprom.c b/drivers/nvmem/lpc18xx_eeprom.c
new file mode 100644
index 000000000..a9534a6e8
--- /dev/null
+++ b/drivers/nvmem/lpc18xx_eeprom.c
@@ -0,0 +1,288 @@
+/*
+ * NXP LPC18xx/LPC43xx EEPROM memory NVMEM driver
+ *
+ * Copyright (c) 2015 Ariel D'Alessandro <ariel@vanguardiasur.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/nvmem-provider.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+
+/* Registers */
+#define LPC18XX_EEPROM_AUTOPROG			0x00c
+#define LPC18XX_EEPROM_AUTOPROG_WORD		0x1
+
+#define LPC18XX_EEPROM_CLKDIV			0x014
+
+#define LPC18XX_EEPROM_PWRDWN			0x018
+#define LPC18XX_EEPROM_PWRDWN_NO		0x0
+#define LPC18XX_EEPROM_PWRDWN_YES		0x1
+
+#define LPC18XX_EEPROM_INTSTAT			0xfe0
+#define LPC18XX_EEPROM_INTSTAT_END_OF_PROG	BIT(2)
+
+#define LPC18XX_EEPROM_INTSTATCLR		0xfe8
+#define LPC18XX_EEPROM_INTSTATCLR_PROG_CLR_ST	BIT(2)
+
+/* Fixed page size (bytes) */
+#define LPC18XX_EEPROM_PAGE_SIZE		0x80
+
+/* EEPROM device requires a ~1500 kHz clock (min 800 kHz, max 1600 kHz) */
+#define LPC18XX_EEPROM_CLOCK_HZ			1500000
+
+/* EEPROM requires 3 ms of erase/program time between each writing */
+#define LPC18XX_EEPROM_PROGRAM_TIME		3
+
+struct lpc18xx_eeprom_dev {
+	struct clk *clk;
+	void __iomem *reg_base;
+	void __iomem *mem_base;
+	struct nvmem_device *nvmem;
+	unsigned reg_bytes;
+	unsigned val_bytes;
+	int size;
+};
+
+static inline void lpc18xx_eeprom_writel(struct lpc18xx_eeprom_dev *eeprom,
+					 u32 reg, u32 val)
+{
+	writel(val, eeprom->reg_base + reg);
+}
+
+static inline u32 lpc18xx_eeprom_readl(struct lpc18xx_eeprom_dev *eeprom,
+				       u32 reg)
+{
+	return readl(eeprom->reg_base + reg);
+}
+
+static int lpc18xx_eeprom_busywait_until_prog(struct lpc18xx_eeprom_dev *eeprom)
+{
+	unsigned long end;
+	u32 val;
+
+	/* Wait until EEPROM program operation has finished */
+	end = jiffies + msecs_to_jiffies(LPC18XX_EEPROM_PROGRAM_TIME * 10);
+
+	while (time_is_after_jiffies(end)) {
+		val = lpc18xx_eeprom_readl(eeprom, LPC18XX_EEPROM_INTSTAT);
+
+		if (val & LPC18XX_EEPROM_INTSTAT_END_OF_PROG) {
+			lpc18xx_eeprom_writel(eeprom, LPC18XX_EEPROM_INTSTATCLR,
+					LPC18XX_EEPROM_INTSTATCLR_PROG_CLR_ST);
+			return 0;
+		}
+
+		usleep_range(LPC18XX_EEPROM_PROGRAM_TIME * USEC_PER_MSEC,
+			     (LPC18XX_EEPROM_PROGRAM_TIME + 1) * USEC_PER_MSEC);
+	}
+
+	return -ETIMEDOUT;
+}
+
+static int lpc18xx_eeprom_gather_write(void *context, unsigned int reg,
+				       void *val, size_t bytes)
+{
+	struct lpc18xx_eeprom_dev *eeprom = context;
+	unsigned int offset = reg;
+	int ret;
+
+	/*
+	 * The last page contains the EEPROM initialization data and is not
+	 * writable.
+	 */
+	if ((reg > eeprom->size - LPC18XX_EEPROM_PAGE_SIZE) ||
+			(reg + bytes > eeprom->size - LPC18XX_EEPROM_PAGE_SIZE))
+		return -EINVAL;
+
+
+	lpc18xx_eeprom_writel(eeprom, LPC18XX_EEPROM_PWRDWN,
+			      LPC18XX_EEPROM_PWRDWN_NO);
+
+	/* Wait 100 us while the EEPROM wakes up */
+	usleep_range(100, 200);
+
+	while (bytes) {
+		writel(*(u32 *)val, eeprom->mem_base + offset);
+		ret = lpc18xx_eeprom_busywait_until_prog(eeprom);
+		if (ret < 0)
+			return ret;
+
+		bytes -= eeprom->val_bytes;
+		val += eeprom->val_bytes;
+		offset += eeprom->val_bytes;
+	}
+
+	lpc18xx_eeprom_writel(eeprom, LPC18XX_EEPROM_PWRDWN,
+			      LPC18XX_EEPROM_PWRDWN_YES);
+
+	return 0;
+}
+
+static int lpc18xx_eeprom_read(void *context, unsigned int offset,
+			       void *val, size_t bytes)
+{
+	struct lpc18xx_eeprom_dev *eeprom = context;
+
+	lpc18xx_eeprom_writel(eeprom, LPC18XX_EEPROM_PWRDWN,
+			      LPC18XX_EEPROM_PWRDWN_NO);
+
+	/* Wait 100 us while the EEPROM wakes up */
+	usleep_range(100, 200);
+
+	while (bytes) {
+		*(u32 *)val = readl(eeprom->mem_base + offset);
+		bytes -= eeprom->val_bytes;
+		val += eeprom->val_bytes;
+		offset += eeprom->val_bytes;
+	}
+
+	lpc18xx_eeprom_writel(eeprom, LPC18XX_EEPROM_PWRDWN,
+			      LPC18XX_EEPROM_PWRDWN_YES);
+
+	return 0;
+}
+
+
+static struct nvmem_config lpc18xx_nvmem_config = {
+	.name = "lpc18xx-eeprom",
+	.stride = 4,
+	.word_size = 4,
+	.reg_read = lpc18xx_eeprom_read,
+	.reg_write = lpc18xx_eeprom_gather_write,
+};
+
+static int lpc18xx_eeprom_probe(struct platform_device *pdev)
+{
+	struct lpc18xx_eeprom_dev *eeprom;
+	struct device *dev = &pdev->dev;
+	struct reset_control *rst;
+	unsigned long clk_rate;
+	struct resource *res;
+	int ret;
+
+	eeprom = devm_kzalloc(dev, sizeof(*eeprom), GFP_KERNEL);
+	if (!eeprom)
+		return -ENOMEM;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "reg");
+	eeprom->reg_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(eeprom->reg_base))
+		return PTR_ERR(eeprom->reg_base);
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mem");
+	eeprom->mem_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(eeprom->mem_base))
+		return PTR_ERR(eeprom->mem_base);
+
+	eeprom->clk = devm_clk_get(&pdev->dev, "eeprom");
+	if (IS_ERR(eeprom->clk)) {
+		dev_err(&pdev->dev, "failed to get eeprom clock\n");
+		return PTR_ERR(eeprom->clk);
+	}
+
+	ret = clk_prepare_enable(eeprom->clk);
+	if (ret < 0) {
+		dev_err(dev, "failed to prepare/enable eeprom clk: %d\n", ret);
+		return ret;
+	}
+
+	rst = devm_reset_control_get_exclusive(dev, NULL);
+	if (IS_ERR(rst)) {
+		dev_err(dev, "failed to get reset: %ld\n", PTR_ERR(rst));
+		ret = PTR_ERR(rst);
+		goto err_clk;
+	}
+
+	ret = reset_control_assert(rst);
+	if (ret < 0) {
+		dev_err(dev, "failed to assert reset: %d\n", ret);
+		goto err_clk;
+	}
+
+	eeprom->val_bytes = 4;
+	eeprom->reg_bytes = 4;
+
+	/*
+	 * Clock rate is generated by dividing the system bus clock by the
+	 * division factor, contained in the divider register (minus 1 encoded).
+	 */
+	clk_rate = clk_get_rate(eeprom->clk);
+	clk_rate = DIV_ROUND_UP(clk_rate, LPC18XX_EEPROM_CLOCK_HZ) - 1;
+	lpc18xx_eeprom_writel(eeprom, LPC18XX_EEPROM_CLKDIV, clk_rate);
+
+	/*
+	 * Writing a single word to the page will start the erase/program cycle
+	 * automatically
+	 */
+	lpc18xx_eeprom_writel(eeprom, LPC18XX_EEPROM_AUTOPROG,
+			      LPC18XX_EEPROM_AUTOPROG_WORD);
+
+	lpc18xx_eeprom_writel(eeprom, LPC18XX_EEPROM_PWRDWN,
+			      LPC18XX_EEPROM_PWRDWN_YES);
+
+	eeprom->size = resource_size(res);
+	lpc18xx_nvmem_config.size = resource_size(res);
+	lpc18xx_nvmem_config.dev = dev;
+	lpc18xx_nvmem_config.priv = eeprom;
+
+	eeprom->nvmem = nvmem_register(&lpc18xx_nvmem_config);
+	if (IS_ERR(eeprom->nvmem)) {
+		ret = PTR_ERR(eeprom->nvmem);
+		goto err_clk;
+	}
+
+	platform_set_drvdata(pdev, eeprom);
+
+	return 0;
+
+err_clk:
+	clk_disable_unprepare(eeprom->clk);
+
+	return ret;
+}
+
+static int lpc18xx_eeprom_remove(struct platform_device *pdev)
+{
+	struct lpc18xx_eeprom_dev *eeprom = platform_get_drvdata(pdev);
+	int ret;
+
+	ret = nvmem_unregister(eeprom->nvmem);
+	if (ret < 0)
+		return ret;
+
+	clk_disable_unprepare(eeprom->clk);
+
+	return 0;
+}
+
+static const struct of_device_id lpc18xx_eeprom_of_match[] = {
+	{ .compatible = "nxp,lpc1857-eeprom" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, lpc18xx_eeprom_of_match);
+
+static struct platform_driver lpc18xx_eeprom_driver = {
+	.probe = lpc18xx_eeprom_probe,
+	.remove = lpc18xx_eeprom_remove,
+	.driver = {
+		.name = "lpc18xx-eeprom",
+		.of_match_table = lpc18xx_eeprom_of_match,
+	},
+};
+
+module_platform_driver(lpc18xx_eeprom_driver);
+
+MODULE_AUTHOR("Ariel D'Alessandro <ariel@vanguardiasur.com.ar>");
+MODULE_DESCRIPTION("NXP LPC18xx EEPROM memory Driver");
+MODULE_LICENSE("GPL v2");