1 files changed, 426 insertions, 0 deletions
diff --git a/drivers/memory/ti-aemif.c b/drivers/memory/ti-aemif.c
new file mode 100644
index 000000000..ca7d97a9a
--- /dev/null
+++ b/drivers/memory/ti-aemif.c
@@ -0,0 +1,426 @@
+/*
+ * TI AEMIF driver
+ *
+ * Copyright (C) 2010 - 2013 Texas Instruments Incorporated. http://www.ti.com/
+ *
+ * Authors:
+ * Murali Karicheri <m-karicheri2@ti.com>
+ * Ivan Khoronzhuk <ivan.khoronzhuk@ti.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/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+
+#define TA_SHIFT	2
+#define RHOLD_SHIFT	4
+#define RSTROBE_SHIFT	7
+#define RSETUP_SHIFT	13
+#define WHOLD_SHIFT	17
+#define WSTROBE_SHIFT	20
+#define WSETUP_SHIFT	26
+#define EW_SHIFT	30
+#define SS_SHIFT	31
+
+#define TA(x)		((x) << TA_SHIFT)
+#define RHOLD(x)	((x) << RHOLD_SHIFT)
+#define RSTROBE(x)	((x) << RSTROBE_SHIFT)
+#define RSETUP(x)	((x) << RSETUP_SHIFT)
+#define WHOLD(x)	((x) << WHOLD_SHIFT)
+#define WSTROBE(x)	((x) << WSTROBE_SHIFT)
+#define WSETUP(x)	((x) << WSETUP_SHIFT)
+#define EW(x)		((x) << EW_SHIFT)
+#define SS(x)		((x) << SS_SHIFT)
+
+#define ASIZE_MAX	0x1
+#define TA_MAX		0x3
+#define RHOLD_MAX	0x7
+#define RSTROBE_MAX	0x3f
+#define RSETUP_MAX	0xf
+#define WHOLD_MAX	0x7
+#define WSTROBE_MAX	0x3f
+#define WSETUP_MAX	0xf
+#define EW_MAX		0x1
+#define SS_MAX		0x1
+#define NUM_CS		4
+
+#define TA_VAL(x)	(((x) & TA(TA_MAX)) >> TA_SHIFT)
+#define RHOLD_VAL(x)	(((x) & RHOLD(RHOLD_MAX)) >> RHOLD_SHIFT)
+#define RSTROBE_VAL(x)	(((x) & RSTROBE(RSTROBE_MAX)) >> RSTROBE_SHIFT)
+#define RSETUP_VAL(x)	(((x) & RSETUP(RSETUP_MAX)) >> RSETUP_SHIFT)
+#define WHOLD_VAL(x)	(((x) & WHOLD(WHOLD_MAX)) >> WHOLD_SHIFT)
+#define WSTROBE_VAL(x)	(((x) & WSTROBE(WSTROBE_MAX)) >> WSTROBE_SHIFT)
+#define WSETUP_VAL(x)	(((x) & WSETUP(WSETUP_MAX)) >> WSETUP_SHIFT)
+#define EW_VAL(x)	(((x) & EW(EW_MAX)) >> EW_SHIFT)
+#define SS_VAL(x)	(((x) & SS(SS_MAX)) >> SS_SHIFT)
+
+#define NRCSR_OFFSET	0x00
+#define AWCCR_OFFSET	0x04
+#define A1CR_OFFSET	0x10
+
+#define ACR_ASIZE_MASK	0x3
+#define ACR_EW_MASK	BIT(30)
+#define ACR_SS_MASK	BIT(31)
+#define ASIZE_16BIT	1
+
+#define CONFIG_MASK	(TA(TA_MAX) | \
+				RHOLD(RHOLD_MAX) | \
+				RSTROBE(RSTROBE_MAX) |	\
+				RSETUP(RSETUP_MAX) | \
+				WHOLD(WHOLD_MAX) | \
+				WSTROBE(WSTROBE_MAX) | \
+				WSETUP(WSETUP_MAX) | \
+				EW(EW_MAX) | SS(SS_MAX) | \
+				ASIZE_MAX)
+
+/**
+ * struct aemif_cs_data: structure to hold cs parameters
+ * @cs: chip-select number
+ * @wstrobe: write strobe width, ns
+ * @rstrobe: read strobe width, ns
+ * @wsetup: write setup width, ns
+ * @whold: write hold width, ns
+ * @rsetup: read setup width, ns
+ * @rhold: read hold width, ns
+ * @ta: minimum turn around time, ns
+ * @enable_ss: enable/disable select strobe mode
+ * @enable_ew: enable/disable extended wait mode
+ * @asize: width of the asynchronous device's data bus
+ */
+struct aemif_cs_data {
+	u8	cs;
+	u16	wstrobe;
+	u16	rstrobe;
+	u8	wsetup;
+	u8	whold;
+	u8	rsetup;
+	u8	rhold;
+	u8	ta;
+	u8	enable_ss;
+	u8	enable_ew;
+	u8	asize;
+};
+
+/**
+ * struct aemif_device: structure to hold device data
+ * @base: base address of AEMIF registers
+ * @clk: source clock
+ * @clk_rate: clock's rate in kHz
+ * @num_cs: number of assigned chip-selects
+ * @cs_offset: start number of cs nodes
+ * @cs_data: array of chip-select settings
+ */
+struct aemif_device {
+	void __iomem *base;
+	struct clk *clk;
+	unsigned long clk_rate;
+	u8 num_cs;
+	int cs_offset;
+	struct aemif_cs_data cs_data[NUM_CS];
+};
+
+/**
+ * aemif_calc_rate - calculate timing data.
+ * @pdev: platform device to calculate for
+ * @wanted: The cycle time needed in nanoseconds.
+ * @clk: The input clock rate in kHz.
+ * @max: The maximum divider value that can be programmed.
+ *
+ * On success, returns the calculated timing value minus 1 for easy
+ * programming into AEMIF timing registers, else negative errno.
+ */
+static int aemif_calc_rate(struct platform_device *pdev, int wanted,
+			   unsigned long clk, int max)
+{
+	int result;
+
+	result = DIV_ROUND_UP((wanted * clk), NSEC_PER_MSEC) - 1;
+
+	dev_dbg(&pdev->dev, "%s: result %d from %ld, %d\n", __func__, result,
+		clk, wanted);
+
+	/* It is generally OK to have a more relaxed timing than requested... */
+	if (result < 0)
+		result = 0;
+
+	/* ... But configuring tighter timings is not an option. */
+	else if (result > max)
+		result = -EINVAL;
+
+	return result;
+}
+
+/**
+ * aemif_config_abus - configure async bus parameters
+ * @pdev: platform device to configure for
+ * @csnum: aemif chip select number
+ *
+ * This function programs the given timing values (in real clock) into the
+ * AEMIF registers taking the AEMIF clock into account.
+ *
+ * This function does not use any locking while programming the AEMIF
+ * because it is expected that there is only one user of a given
+ * chip-select.
+ *
+ * Returns 0 on success, else negative errno.
+ */
+static int aemif_config_abus(struct platform_device *pdev, int csnum)
+{
+	struct aemif_device *aemif = platform_get_drvdata(pdev);
+	struct aemif_cs_data *data = &aemif->cs_data[csnum];
+	int ta, rhold, rstrobe, rsetup, whold, wstrobe, wsetup;
+	unsigned long clk_rate = aemif->clk_rate;
+	unsigned offset;
+	u32 set, val;
+
+	offset = A1CR_OFFSET + (data->cs - aemif->cs_offset) * 4;
+
+	ta	= aemif_calc_rate(pdev, data->ta, clk_rate, TA_MAX);
+	rhold	= aemif_calc_rate(pdev, data->rhold, clk_rate, RHOLD_MAX);
+	rstrobe	= aemif_calc_rate(pdev, data->rstrobe, clk_rate, RSTROBE_MAX);
+	rsetup	= aemif_calc_rate(pdev, data->rsetup, clk_rate, RSETUP_MAX);
+	whold	= aemif_calc_rate(pdev, data->whold, clk_rate, WHOLD_MAX);
+	wstrobe	= aemif_calc_rate(pdev, data->wstrobe, clk_rate, WSTROBE_MAX);
+	wsetup	= aemif_calc_rate(pdev, data->wsetup, clk_rate, WSETUP_MAX);
+
+	if (ta < 0 || rhold < 0 || rstrobe < 0 || rsetup < 0 ||
+	    whold < 0 || wstrobe < 0 || wsetup < 0) {
+		dev_err(&pdev->dev, "%s: cannot get suitable timings\n",
+			__func__);
+		return -EINVAL;
+	}
+
+	set = TA(ta) | RHOLD(rhold) | RSTROBE(rstrobe) | RSETUP(rsetup) |
+		WHOLD(whold) | WSTROBE(wstrobe) | WSETUP(wsetup);
+
+	set |= (data->asize & ACR_ASIZE_MASK);
+	if (data->enable_ew)
+		set |= ACR_EW_MASK;
+	if (data->enable_ss)
+		set |= ACR_SS_MASK;
+
+	val = readl(aemif->base + offset);
+	val &= ~CONFIG_MASK;
+	val |= set;
+	writel(val, aemif->base + offset);
+
+	return 0;
+}
+
+static inline int aemif_cycles_to_nsec(int val, unsigned long clk_rate)
+{
+	return ((val + 1) * NSEC_PER_MSEC) / clk_rate;
+}
+
+/**
+ * aemif_get_hw_params - function to read hw register values
+ * @pdev: platform device to read for
+ * @csnum: aemif chip select number
+ *
+ * This function reads the defaults from the registers and update
+ * the timing values. Required for get/set commands and also for
+ * the case when driver needs to use defaults in hardware.
+ */
+static void aemif_get_hw_params(struct platform_device *pdev, int csnum)
+{
+	struct aemif_device *aemif = platform_get_drvdata(pdev);
+	struct aemif_cs_data *data = &aemif->cs_data[csnum];
+	unsigned long clk_rate = aemif->clk_rate;
+	u32 val, offset;
+
+	offset = A1CR_OFFSET + (data->cs - aemif->cs_offset) * 4;
+	val = readl(aemif->base + offset);
+
+	data->ta = aemif_cycles_to_nsec(TA_VAL(val), clk_rate);
+	data->rhold = aemif_cycles_to_nsec(RHOLD_VAL(val), clk_rate);
+	data->rstrobe = aemif_cycles_to_nsec(RSTROBE_VAL(val), clk_rate);
+	data->rsetup = aemif_cycles_to_nsec(RSETUP_VAL(val), clk_rate);
+	data->whold = aemif_cycles_to_nsec(WHOLD_VAL(val), clk_rate);
+	data->wstrobe = aemif_cycles_to_nsec(WSTROBE_VAL(val), clk_rate);
+	data->wsetup = aemif_cycles_to_nsec(WSETUP_VAL(val), clk_rate);
+	data->enable_ew = EW_VAL(val);
+	data->enable_ss = SS_VAL(val);
+	data->asize = val & ASIZE_MAX;
+}
+
+/**
+ * of_aemif_parse_abus_config - parse CS configuration from DT
+ * @pdev: platform device to parse for
+ * @np: device node ptr
+ *
+ * This function update the emif async bus configuration based on the values
+ * configured in a cs device binding node.
+ */
+static int of_aemif_parse_abus_config(struct platform_device *pdev,
+				      struct device_node *np)
+{
+	struct aemif_device *aemif = platform_get_drvdata(pdev);
+	struct aemif_cs_data *data;
+	u32 cs;
+	u32 val;
+
+	if (of_property_read_u32(np, "ti,cs-chipselect", &cs)) {
+		dev_dbg(&pdev->dev, "cs property is required");
+		return -EINVAL;
+	}
+
+	if (cs - aemif->cs_offset >= NUM_CS || cs < aemif->cs_offset) {
+		dev_dbg(&pdev->dev, "cs number is incorrect %d", cs);
+		return -EINVAL;
+	}
+
+	if (aemif->num_cs >= NUM_CS) {
+		dev_dbg(&pdev->dev, "cs count is more than %d", NUM_CS);
+		return -EINVAL;
+	}
+
+	data = &aemif->cs_data[aemif->num_cs];
+	data->cs = cs;
+
+	/* read the current value in the hw register */
+	aemif_get_hw_params(pdev, aemif->num_cs++);
+
+	/* override the values from device node */
+	if (!of_property_read_u32(np, "ti,cs-min-turnaround-ns", &val))
+		data->ta = val;
+
+	if (!of_property_read_u32(np, "ti,cs-read-hold-ns", &val))
+		data->rhold = val;
+
+	if (!of_property_read_u32(np, "ti,cs-read-strobe-ns", &val))
+		data->rstrobe = val;
+
+	if (!of_property_read_u32(np, "ti,cs-read-setup-ns", &val))
+		data->rsetup = val;
+
+	if (!of_property_read_u32(np, "ti,cs-write-hold-ns", &val))
+		data->whold = val;
+
+	if (!of_property_read_u32(np, "ti,cs-write-strobe-ns", &val))
+		data->wstrobe = val;
+
+	if (!of_property_read_u32(np, "ti,cs-write-setup-ns", &val))
+		data->wsetup = val;
+
+	if (!of_property_read_u32(np, "ti,cs-bus-width", &val))
+		if (val == 16)
+			data->asize = 1;
+	data->enable_ew = of_property_read_bool(np, "ti,cs-extended-wait-mode");
+	data->enable_ss = of_property_read_bool(np, "ti,cs-select-strobe-mode");
+	return 0;
+}
+
+static const struct of_device_id aemif_of_match[] = {
+	{ .compatible = "ti,davinci-aemif", },
+	{ .compatible = "ti,da850-aemif", },
+	{},
+};
+
+static int aemif_probe(struct platform_device *pdev)
+{
+	int i;
+	int ret = -ENODEV;
+	struct resource *res;
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct device_node *child_np;
+	struct aemif_device *aemif;
+
+	if (np == NULL)
+		return 0;
+
+	aemif = devm_kzalloc(dev, sizeof(*aemif), GFP_KERNEL);
+	if (!aemif)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, aemif);
+
+	aemif->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(aemif->clk)) {
+		dev_err(dev, "cannot get clock 'aemif'\n");
+		return PTR_ERR(aemif->clk);
+	}
+
+	clk_prepare_enable(aemif->clk);
+	aemif->clk_rate = clk_get_rate(aemif->clk) / MSEC_PER_SEC;
+
+	if (of_device_is_compatible(np, "ti,da850-aemif"))
+		aemif->cs_offset = 2;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	aemif->base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(aemif->base)) {
+		ret = PTR_ERR(aemif->base);
+		goto error;
+	}
+
+	/*
+	 * For every controller device node, there is a cs device node that
+	 * describe the bus configuration parameters. This functions iterate
+	 * over these nodes and update the cs data array.
+	 */
+	for_each_available_child_of_node(np, child_np) {
+		ret = of_aemif_parse_abus_config(pdev, child_np);
+		if (ret < 0)
+			goto error;
+	}
+
+	for (i = 0; i < aemif->num_cs; i++) {
+		ret = aemif_config_abus(pdev, i);
+		if (ret < 0) {
+			dev_err(dev, "Error configuring chip select %d\n",
+				aemif->cs_data[i].cs);
+			goto error;
+		}
+	}
+
+	/*
+	 * Create a child devices explicitly from here to
+	 * guarantee that the child will be probed after the AEMIF timing
+	 * parameters are set.
+	 */
+	for_each_available_child_of_node(np, child_np) {
+		ret = of_platform_populate(child_np, NULL, NULL, dev);
+		if (ret < 0)
+			goto error;
+	}
+
+	return 0;
+error:
+	clk_disable_unprepare(aemif->clk);
+	return ret;
+}
+
+static int aemif_remove(struct platform_device *pdev)
+{
+	struct aemif_device *aemif = platform_get_drvdata(pdev);
+
+	clk_disable_unprepare(aemif->clk);
+	return 0;
+}
+
+static struct platform_driver aemif_driver = {
+	.probe = aemif_probe,
+	.remove = aemif_remove,
+	.driver = {
+		.name = KBUILD_MODNAME,
+		.of_match_table = of_match_ptr(aemif_of_match),
+	},
+};
+
+module_platform_driver(aemif_driver);
+
+MODULE_AUTHOR("Murali Karicheri <m-karicheri2@ti.com>");
+MODULE_AUTHOR("Ivan Khoronzhuk <ivan.khoronzhuk@ti.com>");
+MODULE_DESCRIPTION("Texas Instruments AEMIF driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" KBUILD_MODNAME);