remoteproc: imx_rproc: add a NXP/Freescale imx_rproc driver

Provide a basic driver to control Cortex M4 co-processor found
on NXP i.MX7D and i.MX6SX.
Currently it is able to resolve addresses between M4 and main CPU,
start and stop the co-processor. Other functionality is not provided
or test.

This driver was tested on NXP i.MX7D and expected to work on
i.MX6SX as well.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

3 files changed, 436 insertions, 0 deletions

diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
index 8891a8e..79f903a 100644
--- a/drivers/remoteproc/Kconfig
+++ b/drivers/remoteproc/Kconfig
@@ -12,6 +12,15 @@ config REMOTEPROC
 
 if REMOTEPROC
 
+config IMX_REMOTEPROC
+	tristate "IMX6/7 remoteproc support"
+	depends on SOC_IMX6SX || SOC_IMX7D
+	help
+	  Say y here to support iMX's remote processors (Cortex M4
+	  on iMX7D) via the remote processor framework.
+
+	  It's safe to say N here.
+
 config OMAP_REMOTEPROC
 	tristate "OMAP remoteproc support"
 	depends on HAS_DMA
diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile
index f1ce5fc..1a0b3dd 100644
--- a/drivers/remoteproc/Makefile
+++ b/drivers/remoteproc/Makefile
@@ -8,6 +8,7 @@ remoteproc-y				+= remoteproc_debugfs.o
 remoteproc-y				+= remoteproc_sysfs.o
 remoteproc-y				+= remoteproc_virtio.o
 remoteproc-y				+= remoteproc_elf_loader.o
+obj-$(CONFIG_IMX_REMOTEPROC)		+= imx_rproc.o
 obj-$(CONFIG_OMAP_REMOTEPROC)		+= omap_remoteproc.o
 obj-$(CONFIG_WKUP_M3_RPROC)		+= wkup_m3_rproc.o
 obj-$(CONFIG_DA8XX_REMOTEPROC)		+= da8xx_remoteproc.o
diff --git a/drivers/remoteproc/imx_rproc.c b/drivers/remoteproc/imx_rproc.c
new file mode 100644
index 0000000..612d914
--- /dev/null
+++ b/drivers/remoteproc/imx_rproc.c
@@ -0,0 +1,426 @@
+/*
+ * Copyright (c) 2017 Pengutronix, Oleksij Rempel <kernel@pengutronix.de>
+ *
+ * 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/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/remoteproc.h>
+
+#define IMX7D_SRC_SCR			0x0C
+#define IMX7D_ENABLE_M4			BIT(3)
+#define IMX7D_SW_M4P_RST		BIT(2)
+#define IMX7D_SW_M4C_RST		BIT(1)
+#define IMX7D_SW_M4C_NON_SCLR_RST	BIT(0)
+
+#define IMX7D_M4_RST_MASK		(IMX7D_ENABLE_M4 | IMX7D_SW_M4P_RST \
+					 | IMX7D_SW_M4C_RST \
+					 | IMX7D_SW_M4C_NON_SCLR_RST)
+
+#define IMX7D_M4_START			(IMX7D_ENABLE_M4 | IMX7D_SW_M4P_RST \
+					 | IMX7D_SW_M4C_RST)
+#define IMX7D_M4_STOP			IMX7D_SW_M4C_NON_SCLR_RST
+
+/* Address: 0x020D8000 */
+#define IMX6SX_SRC_SCR			0x00
+#define IMX6SX_ENABLE_M4		BIT(22)
+#define IMX6SX_SW_M4P_RST		BIT(12)
+#define IMX6SX_SW_M4C_NON_SCLR_RST	BIT(4)
+#define IMX6SX_SW_M4C_RST		BIT(3)
+
+#define IMX6SX_M4_START			(IMX6SX_ENABLE_M4 | IMX6SX_SW_M4P_RST \
+					 | IMX6SX_SW_M4C_RST)
+#define IMX6SX_M4_STOP			IMX6SX_SW_M4C_NON_SCLR_RST
+#define IMX6SX_M4_RST_MASK		(IMX6SX_ENABLE_M4 | IMX6SX_SW_M4P_RST \
+					 | IMX6SX_SW_M4C_NON_SCLR_RST \
+					 | IMX6SX_SW_M4C_RST)
+
+#define IMX7D_RPROC_MEM_MAX		8
+
+/**
+ * struct imx_rproc_mem - slim internal memory structure
+ * @cpu_addr: MPU virtual address of the memory region
+ * @sys_addr: Bus address used to access the memory region
+ * @size: Size of the memory region
+ */
+struct imx_rproc_mem {
+	void __iomem *cpu_addr;
+	phys_addr_t sys_addr;
+	size_t size;
+};
+
+/* att flags */
+/* M4 own area. Can be mapped at probe */
+#define ATT_OWN		BIT(1)
+
+/* address translation table */
+struct imx_rproc_att {
+	u32 da;	/* device address (From Cortex M4 view)*/
+	u32 sa;	/* system bus address */
+	u32 size; /* size of reg range */
+	int flags;
+};
+
+struct imx_rproc_dcfg {
+	u32				src_reg;
+	u32				src_mask;
+	u32				src_start;
+	u32				src_stop;
+	const struct imx_rproc_att	*att;
+	size_t				att_size;
+};
+
+struct imx_rproc {
+	struct device			*dev;
+	struct regmap			*regmap;
+	struct rproc			*rproc;
+	const struct imx_rproc_dcfg	*dcfg;
+	struct imx_rproc_mem		mem[IMX7D_RPROC_MEM_MAX];
+	struct clk			*clk;
+};
+
+static const struct imx_rproc_att imx_rproc_att_imx7d[] = {
+	/* dev addr , sys addr  , size	    , flags */
+	/* OCRAM_S (M4 Boot code) - alias */
+	{ 0x00000000, 0x00180000, 0x00008000, 0 },
+	/* OCRAM_S (Code) */
+	{ 0x00180000, 0x00180000, 0x00008000, ATT_OWN },
+	/* OCRAM (Code) - alias */
+	{ 0x00900000, 0x00900000, 0x00020000, 0 },
+	/* OCRAM_EPDC (Code) - alias */
+	{ 0x00920000, 0x00920000, 0x00020000, 0 },
+	/* OCRAM_PXP (Code) - alias */
+	{ 0x00940000, 0x00940000, 0x00008000, 0 },
+	/* TCML (Code) */
+	{ 0x1FFF8000, 0x007F8000, 0x00008000, ATT_OWN },
+	/* DDR (Code) - alias, first part of DDR (Data) */
+	{ 0x10000000, 0x80000000, 0x0FFF0000, 0 },
+
+	/* TCMU (Data) */
+	{ 0x20000000, 0x00800000, 0x00008000, ATT_OWN },
+	/* OCRAM (Data) */
+	{ 0x20200000, 0x00900000, 0x00020000, 0 },
+	/* OCRAM_EPDC (Data) */
+	{ 0x20220000, 0x00920000, 0x00020000, 0 },
+	/* OCRAM_PXP (Data) */
+	{ 0x20240000, 0x00940000, 0x00008000, 0 },
+	/* DDR (Data) */
+	{ 0x80000000, 0x80000000, 0x60000000, 0 },
+};
+
+static const struct imx_rproc_att imx_rproc_att_imx6sx[] = {
+	/* dev addr , sys addr  , size	    , flags */
+	/* TCML (M4 Boot Code) - alias */
+	{ 0x00000000, 0x007F8000, 0x00008000, 0 },
+	/* OCRAM_S (Code) */
+	{ 0x00180000, 0x008F8000, 0x00004000, 0 },
+	/* OCRAM_S (Code) - alias */
+	{ 0x00180000, 0x008FC000, 0x00004000, 0 },
+	/* TCML (Code) */
+	{ 0x1FFF8000, 0x007F8000, 0x00008000, ATT_OWN },
+	/* DDR (Code) - alias, first part of DDR (Data) */
+	{ 0x10000000, 0x80000000, 0x0FFF8000, 0 },
+
+	/* TCMU (Data) */
+	{ 0x20000000, 0x00800000, 0x00008000, ATT_OWN },
+	/* OCRAM_S (Data) - alias? */
+	{ 0x208F8000, 0x008F8000, 0x00004000, 0 },
+	/* DDR (Data) */
+	{ 0x80000000, 0x80000000, 0x60000000, 0 },
+};
+
+static const struct imx_rproc_dcfg imx_rproc_cfg_imx7d = {
+	.src_reg	= IMX7D_SRC_SCR,
+	.src_mask	= IMX7D_M4_RST_MASK,
+	.src_start	= IMX7D_M4_START,
+	.src_stop	= IMX7D_M4_STOP,
+	.att		= imx_rproc_att_imx7d,
+	.att_size	= ARRAY_SIZE(imx_rproc_att_imx7d),
+};
+
+static const struct imx_rproc_dcfg imx_rproc_cfg_imx6sx = {
+	.src_reg	= IMX6SX_SRC_SCR,
+	.src_mask	= IMX6SX_M4_RST_MASK,
+	.src_start	= IMX6SX_M4_START,
+	.src_stop	= IMX6SX_M4_STOP,
+	.att		= imx_rproc_att_imx6sx,
+	.att_size	= ARRAY_SIZE(imx_rproc_att_imx6sx),
+};
+
+static int imx_rproc_start(struct rproc *rproc)
+{
+	struct imx_rproc *priv = rproc->priv;
+	const struct imx_rproc_dcfg *dcfg = priv->dcfg;
+	struct device *dev = priv->dev;
+	int ret;
+
+	ret = regmap_update_bits(priv->regmap, dcfg->src_reg,
+				 dcfg->src_mask, dcfg->src_start);
+	if (ret)
+		dev_err(dev, "Filed to enable M4!\n");
+
+	return ret;
+}
+
+static int imx_rproc_stop(struct rproc *rproc)
+{
+	struct imx_rproc *priv = rproc->priv;
+	const struct imx_rproc_dcfg *dcfg = priv->dcfg;
+	struct device *dev = priv->dev;
+	int ret;
+
+	ret = regmap_update_bits(priv->regmap, dcfg->src_reg,
+				 dcfg->src_mask, dcfg->src_stop);
+	if (ret)
+		dev_err(dev, "Filed to stop M4!\n");
+
+	return ret;
+}
+
+static int imx_rproc_da_to_sys(struct imx_rproc *priv, u64 da,
+			       int len, u64 *sys)
+{
+	const struct imx_rproc_dcfg *dcfg = priv->dcfg;
+	int i;
+
+	/* parse address translation table */
+	for (i = 0; i < dcfg->att_size; i++) {
+		const struct imx_rproc_att *att = &dcfg->att[i];
+
+		if (da >= att->da && da + len < att->da + att->size) {
+			unsigned int offset = da - att->da;
+
+			*sys = att->sa + offset;
+			return 0;
+		}
+	}
+
+	dev_warn(priv->dev, "Translation filed: da = 0x%llx len = 0x%x\n",
+		 da, len);
+	return -ENOENT;
+}
+
+static void *imx_rproc_da_to_va(struct rproc *rproc, u64 da, int len)
+{
+	struct imx_rproc *priv = rproc->priv;
+	void *va = NULL;
+	u64 sys;
+	int i;
+
+	if (len <= 0)
+		return NULL;
+
+	/*
+	 * On device side we have many aliases, so we need to convert device
+	 * address (M4) to system bus address first.
+	 */
+	if (imx_rproc_da_to_sys(priv, da, len, &sys))
+		return NULL;
+
+	for (i = 0; i < IMX7D_RPROC_MEM_MAX; i++) {
+		if (sys >= priv->mem[i].sys_addr && sys + len <
+		    priv->mem[i].sys_addr +  priv->mem[i].size) {
+			unsigned int offset = sys - priv->mem[i].sys_addr;
+			/* __force to make sparse happy with type conversion */
+			va = (__force void *)(priv->mem[i].cpu_addr + offset);
+			break;
+		}
+	}
+
+	dev_dbg(&rproc->dev, "da = 0x%llx len = 0x%x va = 0x%p\n", da, len, va);
+
+	return va;
+}
+
+static const struct rproc_ops imx_rproc_ops = {
+	.start		= imx_rproc_start,
+	.stop		= imx_rproc_stop,
+	.da_to_va       = imx_rproc_da_to_va,
+};
+
+static int imx_rproc_addr_init(struct imx_rproc *priv,
+			       struct platform_device *pdev)
+{
+	const struct imx_rproc_dcfg *dcfg = priv->dcfg;
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	int a, b = 0, err, nph;
+
+	/* remap required addresses */
+	for (a = 0; a < dcfg->att_size; a++) {
+		const struct imx_rproc_att *att = &dcfg->att[a];
+
+		if (!(att->flags & ATT_OWN))
+			continue;
+
+		if (b > IMX7D_RPROC_MEM_MAX)
+			break;
+
+		priv->mem[b].cpu_addr = devm_ioremap(&pdev->dev,
+						     att->sa, att->size);
+		if (IS_ERR(priv->mem[b].cpu_addr)) {
+			dev_err(dev, "devm_ioremap_resource failed\n");
+			err = PTR_ERR(priv->mem[b].cpu_addr);
+			return err;
+		}
+		priv->mem[b].sys_addr = att->sa;
+		priv->mem[b].size = att->size;
+		b++;
+	}
+
+	/* memory-region is optional property */
+	nph = of_count_phandle_with_args(np, "memory-region", NULL);
+	if (nph <= 0)
+		return 0;
+
+	/* remap optional addresses */
+	for (a = 0; a < nph; a++) {
+		struct device_node *node;
+		struct resource res;
+
+		node = of_parse_phandle(np, "memory-region", a);
+		err = of_address_to_resource(node, 0, &res);
+		if (err) {
+			dev_err(dev, "unable to resolve memory region\n");
+			return err;
+		}
+
+		if (b > IMX7D_RPROC_MEM_MAX)
+			break;
+
+		priv->mem[b].cpu_addr = devm_ioremap_resource(&pdev->dev, &res);
+		if (IS_ERR(priv->mem[b].cpu_addr)) {
+			dev_err(dev, "devm_ioremap_resource failed\n");
+			err = PTR_ERR(priv->mem[b].cpu_addr);
+			return err;
+		}
+		priv->mem[b].sys_addr = res.start;
+		priv->mem[b].size = resource_size(&res);
+		b++;
+	}
+
+	return 0;
+}
+
+static int imx_rproc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct imx_rproc *priv;
+	struct rproc *rproc;
+	struct regmap_config config = { .name = "imx-rproc" };
+	const struct imx_rproc_dcfg *dcfg;
+	struct regmap *regmap;
+	int ret;
+
+	regmap = syscon_regmap_lookup_by_phandle(np, "syscon");
+	if (IS_ERR(regmap)) {
+		dev_err(dev, "failed to find syscon\n");
+		return PTR_ERR(regmap);
+	}
+	regmap_attach_dev(dev, regmap, &config);
+
+	/* set some other name then imx */
+	rproc = rproc_alloc(dev, "imx-rproc", &imx_rproc_ops,
+			    NULL, sizeof(*priv));
+	if (!rproc) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	dcfg = of_device_get_match_data(dev);
+	if (!dcfg)
+		return -EINVAL;
+
+	priv = rproc->priv;
+	priv->rproc = rproc;
+	priv->regmap = regmap;
+	priv->dcfg = dcfg;
+	priv->dev = dev;
+
+	dev_set_drvdata(dev, rproc);
+
+	ret = imx_rproc_addr_init(priv, pdev);
+	if (ret) {
+		dev_err(dev, "filed on imx_rproc_addr_init\n");
+		goto err_put_rproc;
+	}
+
+	priv->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(priv->clk)) {
+		dev_err(dev, "Failed to get clock\n");
+		rproc_free(rproc);
+		return PTR_ERR(priv->clk);
+	}
+
+	/*
+	 * clk for M4 block including memory. Should be
+	 * enabled before .start for FW transfer.
+	 */
+	ret = clk_prepare_enable(priv->clk);
+	if (ret) {
+		dev_err(&rproc->dev, "Failed to enable clock\n");
+		rproc_free(rproc);
+		return ret;
+	}
+
+	ret = rproc_add(rproc);
+	if (ret) {
+		dev_err(dev, "rproc_add failed\n");
+		goto err_put_clk;
+	}
+
+	return ret;
+
+err_put_clk:
+	clk_disable_unprepare(priv->clk);
+err_put_rproc:
+	rproc_free(rproc);
+err:
+	return ret;
+}
+
+static int imx_rproc_remove(struct platform_device *pdev)
+{
+	struct rproc *rproc = platform_get_drvdata(pdev);
+	struct imx_rproc *priv = rproc->priv;
+
+	clk_disable_unprepare(priv->clk);
+	rproc_del(rproc);
+	rproc_free(rproc);
+
+	return 0;
+}
+
+static const struct of_device_id imx_rproc_of_match[] = {
+	{ .compatible = "fsl,imx7d-cm4", .data = &imx_rproc_cfg_imx7d },
+	{ .compatible = "fsl,imx6sx-cm4", .data = &imx_rproc_cfg_imx6sx },
+	{},
+};
+MODULE_DEVICE_TABLE(of, imx_rproc_of_match);
+
+static struct platform_driver imx_rproc_driver = {
+	.probe = imx_rproc_probe,
+	.remove = imx_rproc_remove,
+	.driver = {
+		.name = "imx-rproc",
+		.of_match_table = imx_rproc_of_match,
+	},
+};
+
+module_platform_driver(imx_rproc_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("IMX6SX/7D remote processor control driver");
+MODULE_AUTHOR("Oleksij Rempel <o.rempel@pengutronix.de>");