--- /dev/null
+/*
+ * Memory controller driver for ARM PrimeCell PL172
+ * PrimeCell MultiPort Memory Controller (PL172)
+ *
+ * Copyright (C) 2015 Joachim Eastwood <manabian@gmail.com>
+ *
+ * Based on:
+ * TI AEMIF driver, Copyright (C) 2010 - 2013 Texas Instruments Inc.
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/amba/bus.h>
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/time.h>
+
+#define MPMC_STATIC_CFG(n) (0x200 + 0x20 * n)
+#define MPMC_STATIC_CFG_MW_8BIT 0x0
+#define MPMC_STATIC_CFG_MW_16BIT 0x1
+#define MPMC_STATIC_CFG_MW_32BIT 0x2
+#define MPMC_STATIC_CFG_PM BIT(3)
+#define MPMC_STATIC_CFG_PC BIT(6)
+#define MPMC_STATIC_CFG_PB BIT(7)
+#define MPMC_STATIC_CFG_EW BIT(8)
+#define MPMC_STATIC_CFG_B BIT(19)
+#define MPMC_STATIC_CFG_P BIT(20)
+#define MPMC_STATIC_WAIT_WEN(n) (0x204 + 0x20 * n)
+#define MPMC_STATIC_WAIT_WEN_MAX 0x0f
+#define MPMC_STATIC_WAIT_OEN(n) (0x208 + 0x20 * n)
+#define MPMC_STATIC_WAIT_OEN_MAX 0x0f
+#define MPMC_STATIC_WAIT_RD(n) (0x20c + 0x20 * n)
+#define MPMC_STATIC_WAIT_RD_MAX 0x1f
+#define MPMC_STATIC_WAIT_PAGE(n) (0x210 + 0x20 * n)
+#define MPMC_STATIC_WAIT_PAGE_MAX 0x1f
+#define MPMC_STATIC_WAIT_WR(n) (0x214 + 0x20 * n)
+#define MPMC_STATIC_WAIT_WR_MAX 0x1f
+#define MPMC_STATIC_WAIT_TURN(n) (0x218 + 0x20 * n)
+#define MPMC_STATIC_WAIT_TURN_MAX 0x0f
+
+/* Maximum number of static chip selects */
+#define PL172_MAX_CS 4
+
+struct pl172_data {
+ void __iomem *base;
+ unsigned long rate;
+ struct clk *clk;
+};
+
+static int pl172_timing_prop(struct amba_device *adev,
+ const struct device_node *np, const char *name,
+ u32 reg_offset, u32 max, int start)
+{
+ struct pl172_data *pl172 = amba_get_drvdata(adev);
+ int cycles;
+ u32 val;
+
+ if (!of_property_read_u32(np, name, &val)) {
+ cycles = DIV_ROUND_UP(val * pl172->rate, NSEC_PER_MSEC) - start;
+ if (cycles < 0) {
+ cycles = 0;
+ } else if (cycles > max) {
+ dev_err(&adev->dev, "%s timing too tight\n", name);
+ return -EINVAL;
+ }
+
+ writel(cycles, pl172->base + reg_offset);
+ }
+
+ dev_dbg(&adev->dev, "%s: %u cycle(s)\n", name, start +
+ readl(pl172->base + reg_offset));
+
+ return 0;
+}
+
+static int pl172_setup_static(struct amba_device *adev,
+ struct device_node *np, u32 cs)
+{
+ struct pl172_data *pl172 = amba_get_drvdata(adev);
+ u32 cfg;
+ int ret;
+
+ /* MPMC static memory configuration */
+ if (!of_property_read_u32(np, "mpmc,memory-width", &cfg)) {
+ if (cfg == 8) {
+ cfg = MPMC_STATIC_CFG_MW_8BIT;
+ } else if (cfg == 16) {
+ cfg = MPMC_STATIC_CFG_MW_16BIT;
+ } else if (cfg == 32) {
+ cfg = MPMC_STATIC_CFG_MW_32BIT;
+ } else {
+ dev_err(&adev->dev, "invalid memory width cs%u\n", cs);
+ return -EINVAL;
+ }
+ } else {
+ dev_err(&adev->dev, "memory-width property required\n");
+ return -EINVAL;
+ }
+
+ if (of_property_read_bool(np, "mpmc,async-page-mode"))
+ cfg |= MPMC_STATIC_CFG_PM;
+
+ if (of_property_read_bool(np, "mpmc,cs-active-high"))
+ cfg |= MPMC_STATIC_CFG_PC;
+
+ if (of_property_read_bool(np, "mpmc,byte-lane-low"))
+ cfg |= MPMC_STATIC_CFG_PB;
+
+ if (of_property_read_bool(np, "mpmc,extended-wait"))
+ cfg |= MPMC_STATIC_CFG_EW;
+
+ if (of_property_read_bool(np, "mpmc,buffer-enable"))
+ cfg |= MPMC_STATIC_CFG_B;
+
+ if (of_property_read_bool(np, "mpmc,write-protect"))
+ cfg |= MPMC_STATIC_CFG_P;
+
+ writel(cfg, pl172->base + MPMC_STATIC_CFG(cs));
+ dev_dbg(&adev->dev, "mpmc static config cs%u: 0x%08x\n", cs, cfg);
+
+ /* MPMC static memory timing */
+ ret = pl172_timing_prop(adev, np, "mpmc,write-enable-delay",
+ MPMC_STATIC_WAIT_WEN(cs),
+ MPMC_STATIC_WAIT_WEN_MAX, 1);
+ if (ret)
+ goto fail;
+
+ ret = pl172_timing_prop(adev, np, "mpmc,output-enable-delay",
+ MPMC_STATIC_WAIT_OEN(cs),
+ MPMC_STATIC_WAIT_OEN_MAX, 0);
+ if (ret)
+ goto fail;
+
+ ret = pl172_timing_prop(adev, np, "mpmc,read-access-delay",
+ MPMC_STATIC_WAIT_RD(cs),
+ MPMC_STATIC_WAIT_RD_MAX, 1);
+ if (ret)
+ goto fail;
+
+ ret = pl172_timing_prop(adev, np, "mpmc,page-mode-read-delay",
+ MPMC_STATIC_WAIT_PAGE(cs),
+ MPMC_STATIC_WAIT_PAGE_MAX, 1);
+ if (ret)
+ goto fail;
+
+ ret = pl172_timing_prop(adev, np, "mpmc,write-access-delay",
+ MPMC_STATIC_WAIT_WR(cs),
+ MPMC_STATIC_WAIT_WR_MAX, 2);
+ if (ret)
+ goto fail;
+
+ ret = pl172_timing_prop(adev, np, "mpmc,turn-round-delay",
+ MPMC_STATIC_WAIT_TURN(cs),
+ MPMC_STATIC_WAIT_TURN_MAX, 1);
+ if (ret)
+ goto fail;
+
+ return 0;
+fail:
+ dev_err(&adev->dev, "failed to configure cs%u\n", cs);
+ return ret;
+}
+
+static int pl172_parse_cs_config(struct amba_device *adev,
+ struct device_node *np)
+{
+ u32 cs;
+
+ if (!of_property_read_u32(np, "mpmc,cs", &cs)) {
+ if (cs >= PL172_MAX_CS) {
+ dev_err(&adev->dev, "cs%u invalid\n", cs);
+ return -EINVAL;
+ }
+
+ return pl172_setup_static(adev, np, cs);
+ }
+
+ dev_err(&adev->dev, "cs property required\n");
+
+ return -EINVAL;
+}
+
+static const char * const pl172_revisions[] = {"r1", "r2", "r2p3", "r2p4"};
+
+static int pl172_probe(struct amba_device *adev, const struct amba_id *id)
+{
+ struct device_node *child_np, *np = adev->dev.of_node;
+ struct device *dev = &adev->dev;
+ static const char *rev = "?";
+ struct pl172_data *pl172;
+ int ret;
+
+ if (amba_part(adev) == 0x172) {
+ if (amba_rev(adev) < ARRAY_SIZE(pl172_revisions))
+ rev = pl172_revisions[amba_rev(adev)];
+ }
+
+ dev_info(dev, "ARM PL%x revision %s\n", amba_part(adev), rev);
+
+ pl172 = devm_kzalloc(dev, sizeof(*pl172), GFP_KERNEL);
+ if (!pl172)
+ return -ENOMEM;
+
+ pl172->clk = devm_clk_get(dev, "mpmcclk");
+ if (IS_ERR(pl172->clk)) {
+ dev_err(dev, "no mpmcclk provided clock\n");
+ return PTR_ERR(pl172->clk);
+ }
+
+ ret = clk_prepare_enable(pl172->clk);
+ if (ret) {
+ dev_err(dev, "unable to mpmcclk enable clock\n");
+ return ret;
+ }
+
+ pl172->rate = clk_get_rate(pl172->clk) / MSEC_PER_SEC;
+ if (!pl172->rate) {
+ dev_err(dev, "unable to get mpmcclk clock rate\n");
+ ret = -EINVAL;
+ goto err_clk_enable;
+ }
+
+ ret = amba_request_regions(adev, NULL);
+ if (ret) {
+ dev_err(dev, "unable to request AMBA regions\n");
+ goto err_clk_enable;
+ }
+
+ pl172->base = devm_ioremap(dev, adev->res.start,
+ resource_size(&adev->res));
+ if (!pl172->base) {
+ dev_err(dev, "ioremap failed\n");
+ ret = -ENOMEM;
+ goto err_no_ioremap;
+ }
+
+ amba_set_drvdata(adev, pl172);
+
+ /*
+ * Loop through each child node, which represent a chip select, and
+ * configure parameters and timing. If successful; populate devices
+ * under that node.
+ */
+ for_each_available_child_of_node(np, child_np) {
+ ret = pl172_parse_cs_config(adev, child_np);
+ if (ret)
+ continue;
+
+ of_platform_populate(child_np, of_default_bus_match_table,
+ NULL, dev);
+ }
+
+ return 0;
+
+err_no_ioremap:
+ amba_release_regions(adev);
+err_clk_enable:
+ clk_disable_unprepare(pl172->clk);
+ return ret;
+}
+
+static int pl172_remove(struct amba_device *adev)
+{
+ struct pl172_data *pl172 = amba_get_drvdata(adev);
+
+ clk_disable_unprepare(pl172->clk);
+ amba_release_regions(adev);
+
+ return 0;
+}
+
+static const struct amba_id pl172_ids[] = {
+ {
+ .id = 0x07341172,
+ .mask = 0xffffffff,
+ },
+ { 0, 0 },
+};
+MODULE_DEVICE_TABLE(amba, pl172_ids);
+
+static struct amba_driver pl172_driver = {
+ .drv = {
+ .name = "memory-pl172",
+ },
+ .probe = pl172_probe,
+ .remove = pl172_remove,
+ .id_table = pl172_ids,
+};
+module_amba_driver(pl172_driver);
+
+MODULE_AUTHOR("Joachim Eastwood <manabian@gmail.com>");
+MODULE_DESCRIPTION("PL172 Memory Controller Driver");
+MODULE_LICENSE("GPL v2");
projects / linux.git / commitdiff