summaryrefslogtreecommitdiffstats
path: root/drivers/memory/ti-aemif.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/memory/ti-aemif.c')
-rw-r--r--drivers/memory/ti-aemif.c453
1 files changed, 453 insertions, 0 deletions
diff --git a/drivers/memory/ti-aemif.c b/drivers/memory/ti-aemif.c
new file mode 100644
index 0000000000..f81e7df879
--- /dev/null
+++ b/drivers/memory/ti-aemif.c
@@ -0,0 +1,453 @@
+// 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/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/platform_data/ti-aemif.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 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) | SSTROBE(SSTROBE_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_SSTROBE_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 = 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);
+ 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", },
+ {},
+};
+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 device_node *child_np;
+ struct aemif_device *aemif;
+ struct aemif_platform_data *pdata;
+ struct of_dev_auxdata *dev_lookup;
+
+ aemif = devm_kzalloc(dev, sizeof(*aemif), GFP_KERNEL);
+ if (!aemif)
+ return -ENOMEM;
+
+ pdata = dev_get_platdata(&pdev->dev);
+ dev_lookup = pdata ? pdata->dev_lookup : NULL;
+
+ 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);
+ }
+
+ ret = clk_prepare_enable(aemif->clk);
+ if (ret)
+ return ret;
+
+ 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;
+ else if (pdata)
+ aemif->cs_offset = pdata->cs_offset;
+
+ aemif->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(aemif->base)) {
+ ret = PTR_ERR(aemif->base);
+ goto error;
+ }
+
+ 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(np, child_np) {
+ ret = of_aemif_parse_abus_config(pdev, child_np);
+ if (ret < 0) {
+ of_node_put(child_np);
+ goto error;
+ }
+ }
+ } else if (pdata && pdata->num_abus_data > 0) {
+ for (i = 0; i < pdata->num_abus_data; i++, aemif->num_cs++) {
+ aemif->cs_data[i].cs = pdata->abus_data[i].cs;
+ aemif_get_hw_params(pdev, i);
+ }
+ }
+
+ 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.
+ */
+ if (np) {
+ for_each_available_child_of_node(np, child_np) {
+ ret = of_platform_populate(child_np, NULL,
+ dev_lookup, dev);
+ if (ret < 0) {
+ of_node_put(child_np);
+ goto error;
+ }
+ }
+ } else if (pdata) {
+ for (i = 0; i < pdata->num_sub_devices; i++) {
+ pdata->sub_devices[i].dev.parent = dev;
+ ret = platform_device_register(&pdata->sub_devices[i]);
+ if (ret) {
+ dev_warn(dev, "Error register sub device %s\n",
+ pdata->sub_devices[i].name);
+ }
+ }
+ }
+
+ 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 = "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);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-25 09:47:28 +0000