1 files changed, 446 insertions, 0 deletions
diff --git a/drivers/memory/ti-aemif.c b/drivers/memory/ti-aemif.c
new file mode 100644
index 000000000..c8b83c9ed
--- /dev/null
+++ b/drivers/memory/ti-aemif.c
@@ -0,0 +1,446 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * 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>
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/memory/ti-aemif.h>
+#include <linux/module.h>
+#include <linux/mutex.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 SSTROBE_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 SSTROBE(x)	((x) << SSTROBE_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 SSTROBE_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 SSTROBE_VAL(x)	(((x) & SSTROBE(SSTROBE_MAX)) >> SSTROBE_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_SSTROBE_MASK	BIT(31)
+#define ASIZE_16BIT	1
+
+#define TIMINGS_MASK	(TA(TA_MAX) | \
+			RHOLD(RHOLD_MAX) | \
+			RSTROBE(RSTROBE_MAX) |	\
+			RSETUP(RSETUP_MAX) | \
+			WHOLD(WHOLD_MAX) | \
+			WSTROBE(WSTROBE_MAX) | \
+			WSETUP(WSETUP_MAX))
+
+#define CONFIG_MASK	(EW(EW_MAX) | SSTROBE(SSTROBE_MAX) | ASIZE_MAX)
+
+/**
+ * struct aemif_cs_data: structure to hold CS parameters
+ * @timings: timings configuration
+ * @cs: chip-select number
+ * @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 {
+	struct aemif_cs_timings timings;
+	u8	cs;
+	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
+ * @config_cs_lock: lock used to access CS configuration
+ */
+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];
+	struct mutex config_cs_lock;
+};
+
+/**
+ * aemif_check_cs_timings() - Check the validity of a CS timing configuration.
+ * @timings: timings configuration
+ *
+ * @return: 0 if the timing configuration is valid, negative error number otherwise.
+ */
+int aemif_check_cs_timings(struct aemif_cs_timings *timings)
+{
+	if (timings->ta > TA_MAX)
+		return -EINVAL;
+
+	if (timings->rhold > RHOLD_MAX)
+		return -EINVAL;
+
+	if (timings->rstrobe > RSTROBE_MAX)
+		return -EINVAL;
+
+	if (timings->rsetup > RSETUP_MAX)
+		return -EINVAL;
+
+	if (timings->whold > WHOLD_MAX)
+		return -EINVAL;
+
+	if (timings->wstrobe > WSTROBE_MAX)
+		return -EINVAL;
+
+	if (timings->wsetup > WSETUP_MAX)
+		return -EINVAL;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(aemif_check_cs_timings);
+
+/**
+ * aemif_set_cs_timings() - Set the timing configuration of a given chip select.
+ * @aemif: aemif device to configure
+ * @cs: index of the chip select to configure
+ * @timings: timings configuration to set
+ *
+ * @return: 0 on success, else negative errno.
+ */
+int aemif_set_cs_timings(struct aemif_device *aemif, u8 cs,
+			 struct aemif_cs_timings *timings)
+{
+	unsigned int offset;
+	u32 val, set;
+	int ret;
+
+	if (!timings || !aemif)
+		return -EINVAL;
+
+	if (cs > aemif->num_cs)
+		return -EINVAL;
+
+	ret = aemif_check_cs_timings(timings);
+	if (ret)
+		return ret;
+
+	set = TA(timings->ta) | RHOLD(timings->rhold) | RSTROBE(timings->rstrobe) |
+	      RSETUP(timings->rsetup) | WHOLD(timings->whold) |
+	      WSTROBE(timings->wstrobe) | WSETUP(timings->wsetup);
+
+	offset = A1CR_OFFSET + cs * 4;
+
+	mutex_lock(&aemif->config_cs_lock);
+	val = readl(aemif->base + offset);
+	val &= ~TIMINGS_MASK;
+	val |= set;
+	writel(val, aemif->base + offset);
+	mutex_unlock(&aemif->config_cs_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(aemif_set_cs_timings);
+
+/**
+ * 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.
+ *
+ * @return: the calculated timing value minus 1 for easy
+ * programming into AEMIF timing registers.
+ */
+static u32 aemif_calc_rate(struct platform_device *pdev, int wanted, unsigned long clk)
+{
+	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;
+
+	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];
+	unsigned offset;
+	u32 set, val;
+
+	offset = A1CR_OFFSET + (data->cs - aemif->cs_offset) * 4;
+
+	set = (data->asize & ACR_ASIZE_MASK);
+	if (data->enable_ew)
+		set |= ACR_EW_MASK;
+	if (data->enable_ss)
+		set |= ACR_SSTROBE_MASK;
+
+	mutex_lock(&aemif->config_cs_lock);
+	val = readl(aemif->base + offset);
+	val &= ~CONFIG_MASK;
+	val |= set;
+	writel(val, aemif->base + offset);
+	mutex_unlock(&aemif->config_cs_lock);
+
+	return aemif_set_cs_timings(aemif, data->cs - aemif->cs_offset, &data->timings);
+}
+
+/**
+ * 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];
+	u32 val, offset;
+
+	offset = A1CR_OFFSET + (data->cs - aemif->cs_offset) * 4;
+	val = readl(aemif->base + offset);
+
+	data->timings.ta = TA_VAL(val);
+	data->timings.rhold = RHOLD_VAL(val);
+	data->timings.rstrobe = RSTROBE_VAL(val);
+	data->timings.rsetup = RSETUP_VAL(val);
+	data->timings.whold = WHOLD_VAL(val);
+	data->timings.wstrobe = WSTROBE_VAL(val);
+	data->timings.wsetup = WSETUP_VAL(val);
+	data->enable_ew = EW_VAL(val);
+	data->enable_ss = SSTROBE_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);
+	unsigned long clk_rate = aemif->clk_rate;
+	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->timings.ta = aemif_calc_rate(pdev, val, clk_rate);
+
+	if (!of_property_read_u32(np, "ti,cs-read-hold-ns", &val))
+		data->timings.rhold = aemif_calc_rate(pdev, val, clk_rate);
+
+	if (!of_property_read_u32(np, "ti,cs-read-strobe-ns", &val))
+		data->timings.rstrobe = aemif_calc_rate(pdev, val, clk_rate);
+
+	if (!of_property_read_u32(np, "ti,cs-read-setup-ns", &val))
+		data->timings.rsetup = aemif_calc_rate(pdev, val, clk_rate);
+
+	if (!of_property_read_u32(np, "ti,cs-write-hold-ns", &val))
+		data->timings.whold = aemif_calc_rate(pdev, val, clk_rate);
+
+	if (!of_property_read_u32(np, "ti,cs-write-strobe-ns", &val))
+		data->timings.wstrobe = aemif_calc_rate(pdev, val, clk_rate);
+
+	if (!of_property_read_u32(np, "ti,cs-write-setup-ns", &val))
+		data->timings.wsetup = aemif_calc_rate(pdev, val, clk_rate);
+
+	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 aemif_check_cs_timings(&data->timings);
+}
+
+static const struct of_device_id aemif_of_match[] = {
+	{ .compatible = "ti,davinci-aemif", },
+	{ .compatible = "ti,da850-aemif", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, aemif_of_match);
+
+static int aemif_probe(struct platform_device *pdev)
+{
+	int i;
+	int ret = -ENODEV;
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct aemif_device *aemif;
+
+	aemif = devm_kzalloc(dev, sizeof(*aemif), GFP_KERNEL);
+	if (!aemif)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, aemif);
+
+	aemif->clk = devm_clk_get_enabled(dev, NULL);
+	if (IS_ERR(aemif->clk))
+		return dev_err_probe(dev, PTR_ERR(aemif->clk),
+				     "cannot get clock 'aemif'\n");
+
+	aemif->clk_rate = clk_get_rate(aemif->clk) / MSEC_PER_SEC;
+
+	if (np && of_device_is_compatible(np, "ti,da850-aemif"))
+		aemif->cs_offset = 2;
+
+	aemif->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(aemif->base))
+		return PTR_ERR(aemif->base);
+
+	mutex_init(&aemif->config_cs_lock);
+	if (np) {
+		/*
+		 * 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_scoped(np, child_np) {
+			ret = of_aemif_parse_abus_config(pdev, child_np);
+			if (ret < 0)
+				return ret;
+		}
+	}
+
+	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);
+			return ret;
+		}
+	}
+
+	/*
+	 * Create a child devices explicitly from here to guarantee that the
+	 * child will be probed after the AEMIF timing parameters are set.
+	 */
+	if (np) {
+		for_each_available_child_of_node_scoped(np, child_np) {
+			ret = of_platform_populate(child_np, NULL, NULL, dev);
+			if (ret < 0)
+				return ret;
+		}
+	}
+
+	return 0;
+}
+
+static struct platform_driver aemif_driver = {
+	.probe = aemif_probe,
+	.driver = {
+		.name = "ti-aemif",
+		.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);