1 files changed, 301 insertions, 0 deletions
diff --git a/drivers/memory/pl172.c b/drivers/memory/pl172.c
new file mode 100644
index 000000000000..b2ef6072fbf4
--- /dev/null
+++ b/drivers/memory/pl172.c
@@ -0,0 +1,301 @@
+/*
+ * 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, NULL, 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");