[PATCH v4 01/18] remoteproc: st_xp70_rproc: add a xp70 slimcore rproc driver

[Peter Griffin]

XP70 slim core is used as a basis for many IPs in the STi
chipsets such as fdma, display, and demux. To avoid
duplicating the elf loading code in each device driver
an xp70 rproc driver has been created.

This driver is designed to be used by other device drivers
such as fdma, or demux whose IP is based around a xp70 slimcore.
The device driver can call xp70_rproc_alloc() to allocate
an xp70 rproc and xp70_rproc_put() when finished.

This driver takes care of ioremapping the xp70
registers (dmem, imem, slimcore, peripherals), whose offsets
and sizes can change between IP's. It also obtains and enables
any clocks used by the device. This approach avoids having
a double mapping of the registers as xp70_rproc does not register
its own platform device. It also maps well to device tree
abstraction as it allows us to have one dt node for the whole
device.

All of the generic rproc elf loading code can be reused, and
we provide start() stop() hooks to start and stop the xp70
core once the firmware has been loaded. This has been tested
successfully with fdma driver.

Signed-off-by: Peter Griffin <peter.griffin@xxxxxxxxxx>
---
 drivers/remoteproc/Kconfig               |   8 +
 drivers/remoteproc/Makefile              |   1 +
 drivers/remoteproc/st_xp70_rproc.c       | 380 +++++++++++++++++++++++++++++++
 include/linux/remoteproc/st_xp70_rproc.h |  56 +++++
 4 files changed, 445 insertions(+)
 create mode 100644 drivers/remoteproc/st_xp70_rproc.c
 create mode 100644 include/linux/remoteproc/st_xp70_rproc.h

diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
index 72e97d7..9e48fd1 100644
--- a/drivers/remoteproc/Kconfig
+++ b/drivers/remoteproc/Kconfig
@@ -86,4 +86,12 @@ config ST_REMOTEPROC
 	  processor framework.
 	  This can be either built-in or a loadable module.
 
+config ST_XP70_REMOTEPROC
+	tristate "XP70 slim remoteproc support"
+	depends on ARCH_STI
+	select REMOTEPROC
+	help
+	  Say y here to support xp70 slim core.
+	  If unsure say N.
+
 endmenu
diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile
index 279cb2e..b5dab8e 100644
--- a/drivers/remoteproc/Makefile
+++ b/drivers/remoteproc/Makefile
@@ -12,3 +12,4 @@ obj-$(CONFIG_STE_MODEM_RPROC)	 	+= ste_modem_rproc.o
 obj-$(CONFIG_WKUP_M3_RPROC)		+= wkup_m3_rproc.o
 obj-$(CONFIG_DA8XX_REMOTEPROC)		+= da8xx_remoteproc.o
 obj-$(CONFIG_ST_REMOTEPROC)		+= st_remoteproc.o
+obj-$(CONFIG_ST_XP70_REMOTEPROC)	+= st_xp70_rproc.o
diff --git a/drivers/remoteproc/st_xp70_rproc.c b/drivers/remoteproc/st_xp70_rproc.c
new file mode 100644
index 0000000..6a78e7c
--- /dev/null
+++ b/drivers/remoteproc/st_xp70_rproc.c
@@ -0,0 +1,380 @@
+/*
+ * st_xp70_rproc.c
+ *
+ * Copyright (C) 2016 STMicroelectronics
+ * Author: Peter Griffin <peter.griffin@xxxxxx>
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#include <linux/clk.h>
+#include <linux/elf.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/remoteproc.h>
+#include <linux/remoteproc/st_xp70_rproc.h>
+#include "remoteproc_internal.h"
+
+/* slimcore registers */
+#define XP70_ID_OFST		0x0
+#define XP70_VER_OFST		0x4
+
+#define XP70_EN_OFST		0x8
+#define XP70_EN_RUN			BIT(0)
+
+#define XP70_CLK_GATE_OFST	0xC
+#define XP70_CLK_GATE_DIS		BIT(0)
+#define XP70_CLK_GATE_RESET		BIT(2)
+
+#define XP70_SLIM_PC_OFST	0x20
+
+/* dmem registers */
+#define XP70_REV_ID_OFST	0x0
+#define XP70_REV_ID_MIN_MASK		GENMASK(15, 8)
+#define XP70_REV_ID_MIN(id)		((id & XP70_REV_ID_MIN_MASK) >> 8)
+#define XP70_REV_ID_MAJ_MASK		GENMASK(23, 16)
+#define XP70_REV_ID_MAJ(id)		((id & XP70_REV_ID_MAJ_MASK) >> 16)
+
+
+/* peripherals registers */
+#define XP70_STBUS_SYNC_OFST	0xF88
+#define XP70_STBUS_SYNC_DIS		BIT(0)
+
+#define XP70_INT_SET_OFST	0xFD4
+#define XP70_INT_CLR_OFST	0xFD8
+#define XP70_INT_MASK_OFST	0xFDC
+
+#define XP70_CMD_CLR_OFST	0xFC8
+#define XP70_CMD_MASK_OFST	0xFCC
+
+const char *mem_names[XP70_MEM_MAX] = {
+	[DMEM]		= "dmem",
+	[IMEM]		= "imem",
+};
+
+static int xp70_clk_get(struct st_xp70_rproc *xp70_rproc, struct device *dev)
+{
+	int clk, err = 0;
+
+	for (clk = 0; clk < XP70_MAX_CLK; clk++) {
+		xp70_rproc->clks[clk] = of_clk_get(dev->of_node, clk);
+		if (IS_ERR(xp70_rproc->clks[clk])) {
+			err = PTR_ERR(xp70_rproc->clks[clk]);
+			if (err == -EPROBE_DEFER)
+				goto err_put_clks;
+			xp70_rproc->clks[clk] = NULL;
+			break;
+		}
+	}
+
+	return 0;
+
+err_put_clks:
+	while (--clk >= 0)
+		clk_put(xp70_rproc->clks[clk]);
+
+	return err;
+}
+
+static void xp70_clk_disable(struct st_xp70_rproc *xp70_rproc)
+{
+	int clk;
+
+	for (clk = 0; clk < XP70_MAX_CLK && xp70_rproc->clks[clk]; clk++)
+		clk_disable_unprepare(xp70_rproc->clks[clk]);
+}
+
+static int xp70_clk_enable(struct st_xp70_rproc *xp70_rproc)
+{
+	int clk, ret;
+
+	for (clk = 0; clk < XP70_MAX_CLK && xp70_rproc->clks[clk]; clk++) {
+		ret = clk_prepare_enable(xp70_rproc->clks[clk]);
+		if (ret)
+			goto err_disable_clks;
+	}
+
+	return 0;
+
+err_disable_clks:
+	while (--clk >= 0)
+		clk_disable_unprepare(xp70_rproc->clks[clk]);
+
+	return ret;
+}
+
+/**
+ * Remoteproc xp70 specific device handlers
+ */
+static int xp70_rproc_start(struct rproc *rproc)
+{
+	struct device *dev = &rproc->dev;
+	struct st_xp70_rproc *xp70_rproc = rproc->priv;
+	unsigned long hw_id, hw_ver, fw_rev;
+	u32 val, ret = 0;
+
+	ret = xp70_clk_enable(xp70_rproc);
+	if (ret) {
+		dev_err(dev, "Failed to enable clocks\n");
+		goto err_clk;
+	}
+
+	/* disable CPU pipeline clock & reset cpu pipeline */
+	val = XP70_CLK_GATE_DIS | XP70_CLK_GATE_RESET;
+	writel_relaxed(val, xp70_rproc->slimcore + XP70_CLK_GATE_OFST);
+
+	/* disable SLIM core STBus sync */
+	writel_relaxed(XP70_STBUS_SYNC_DIS,
+		xp70_rproc->peri + XP70_STBUS_SYNC_OFST);
+
+	/* enable cpu pipeline clock */
+	writel_relaxed(!XP70_CLK_GATE_DIS,
+		xp70_rproc->slimcore + XP70_CLK_GATE_OFST);
+
+	/* clear int & cmd mailbox */
+	writel_relaxed(~0UL, xp70_rproc->peri + XP70_INT_CLR_OFST);
+	writel_relaxed(~0UL, xp70_rproc->peri + XP70_CMD_CLR_OFST);
+
+	/* enable all channels cmd & int */
+	writel_relaxed(~0UL, xp70_rproc->peri + XP70_INT_MASK_OFST);
+	writel_relaxed(~0UL, xp70_rproc->peri + XP70_CMD_MASK_OFST);
+
+	/* enable cpu */
+	writel(XP70_EN_RUN, xp70_rproc->slimcore + XP70_EN_OFST);
+
+	hw_id = readl_relaxed(xp70_rproc->slimcore + XP70_ID_OFST);
+	hw_ver = readl_relaxed(xp70_rproc->slimcore + XP70_VER_OFST);
+
+	fw_rev = readl_relaxed(xp70_rproc->mem[DMEM].cpu_addr +
+			XP70_REV_ID_OFST);
+
+	dev_info(dev, "fw rev:%ld.%ld on SLIM %ld.%ld\n",
+		 XP70_REV_ID_MAJ(fw_rev), XP70_REV_ID_MIN(fw_rev),
+		 hw_id, hw_ver);
+
+	dev_dbg(dev, "XP70 started\n");
+
+err_clk:
+	return ret;
+}
+
+static int xp70_rproc_stop(struct rproc *rproc)
+{
+	struct st_xp70_rproc *xp70_rproc = rproc->priv;
+	u32 val;
+
+	/* mask all (cmd & int) channels */
+	writel_relaxed(0UL, xp70_rproc->peri + XP70_INT_MASK_OFST);
+	writel_relaxed(0UL, xp70_rproc->peri + XP70_CMD_MASK_OFST);
+
+	/* disable cpu pipeline clock */
+	writel_relaxed(XP70_CLK_GATE_DIS
+		, xp70_rproc->slimcore + XP70_CLK_GATE_OFST);
+
+	writel_relaxed(!XP70_EN_RUN, xp70_rproc->slimcore + XP70_EN_OFST);
+
+	val = readl_relaxed(xp70_rproc->slimcore + XP70_EN_OFST);
+	if (val & XP70_EN_RUN)
+		dev_warn(&rproc->dev, "Failed to disable XP70");
+
+	xp70_clk_disable(xp70_rproc);
+
+	dev_dbg(&rproc->dev, "xp70 stopped\n");
+
+	return 0;
+}
+
+static void *xp70_rproc_da_to_va(struct rproc *rproc, u64 da, int len)
+{
+	struct st_xp70_rproc *xp70_rproc = rproc->priv;
+	void *va = NULL;
+	int i;
+
+	for (i = 0; i < XP70_MEM_MAX; i++) {
+
+		if (da != xp70_rproc->mem[i].bus_addr)
+			continue;
+
+		va = xp70_rproc->mem[i].cpu_addr;
+			break;
+	}
+
+	dev_dbg(&rproc->dev, "%s: da = 0x%llx len = 0x%x va = 0x%p\n"
+		, __func__, da, len, va);
+
+	return va;
+}
+
+static struct rproc_ops xp70_rproc_ops = {
+	.start		= xp70_rproc_start,
+	.stop		= xp70_rproc_stop,
+	.da_to_va       = xp70_rproc_da_to_va,
+};
+
+/**
+ * Firmware handler operations: sanity, boot address, load ...
+ */
+
+static struct resource_table empty_rsc_tbl = {
+	.ver = 1,
+	.num = 0,
+};
+
+static struct resource_table *xp70_rproc_find_rsc_table(struct rproc *rproc,
+					       const struct firmware *fw,
+					       int *tablesz)
+{
+	if (!fw)
+		return NULL;
+
+	*tablesz = sizeof(empty_rsc_tbl);
+	return &empty_rsc_tbl;
+}
+
+static struct resource_table *xp70_rproc_find_loaded_rsc_table(struct rproc *rproc,
+						      const struct firmware *fw)
+{
+	if (!fw)
+		return NULL;
+
+	return &empty_rsc_tbl;
+}
+
+static struct rproc_fw_ops xp70_rproc_fw_ops = {
+	.find_rsc_table = xp70_rproc_find_rsc_table,
+	.find_loaded_rsc_table = xp70_rproc_find_loaded_rsc_table,
+};
+
+/**
+  * xp70_rproc_alloc - allocate and initialise xp70 rproc
+  * @pdev: Pointer to the platform_device struct
+  * @fw_name: Name of firmware for rproc to use
+  *
+  * Function for allocating and initialising a xp70 rproc for use by
+  * device drivers whose IP is based around the xp70 slim core. It
+  * obtains and enables any clocks required by the xp70 core and also
+  * ioremaps the various IO.
+  *
+  * Returns rproc pointer or PTR_ERR() on error.
+  */
+
+struct rproc *xp70_rproc_alloc(struct platform_device *pdev, char *fw_name)
+{
+	struct device *dev = &pdev->dev;
+	struct st_xp70_rproc *xp70_rproc;
+	struct device_node *np = dev->of_node;
+	struct rproc *rproc;
+	struct resource *res;
+	int err, i;
+	const struct rproc_fw_ops *elf_ops;
+
+	if (!np || !fw_name)
+		return ERR_PTR(-EINVAL);
+
+	if (!of_device_is_compatible(np, "st,xp70-rproc"))
+		return ERR_PTR(-EINVAL);
+
+	rproc = rproc_alloc(dev, np->name, &xp70_rproc_ops,
+			fw_name, sizeof(*xp70_rproc));
+	if (!rproc)
+		return ERR_PTR(-ENOMEM);
+
+	rproc->has_iommu = false;
+
+	xp70_rproc = rproc->priv;
+	xp70_rproc->rproc = rproc;
+
+	/* Get standard ELF ops */
+	elf_ops = rproc_get_elf_ops();
+
+	/* Use some generic elf ops */
+	xp70_rproc_fw_ops.load = elf_ops->load;
+	xp70_rproc_fw_ops.sanity_check = elf_ops->sanity_check;
+
+	rproc->fw_ops = &xp70_rproc_fw_ops;
+
+	/* get imem and dmem */
+	for (i = 0; i < ARRAY_SIZE(mem_names); i++) {
+		res = xp70_rproc->mem[i].io_res;
+
+		res = platform_get_resource_byname
+			(pdev, IORESOURCE_MEM, mem_names[i]);
+
+		xp70_rproc->mem[i].cpu_addr = devm_ioremap_resource(dev, res);
+		if (IS_ERR(xp70_rproc->mem[i].cpu_addr)) {
+			dev_err(&pdev->dev, "devm_ioremap_resource failed\n");
+			err = PTR_ERR(xp70_rproc->mem[i].cpu_addr);
+			goto err;
+		}
+		xp70_rproc->mem[i].bus_addr = res->start;
+		xp70_rproc->mem[i].size = resource_size(res);
+	}
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "slimcore");
+
+	xp70_rproc->slimcore = devm_ioremap_resource(dev, res);
+	if (IS_ERR(xp70_rproc->slimcore)) {
+		dev_err(&pdev->dev, "devm_ioremap_resource failed for slimcore\n");
+		err = PTR_ERR(xp70_rproc->slimcore);
+		goto err;
+	}
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "peripherals");
+
+	xp70_rproc->peri = devm_ioremap_resource(dev, res);
+	if (IS_ERR(xp70_rproc->peri)) {
+		dev_err(&pdev->dev, "devm_ioremap_resource failed for peri\n");
+		err = PTR_ERR(xp70_rproc->peri);
+		goto err;
+	}
+
+	err = xp70_clk_get(xp70_rproc, dev);
+	if (err)
+		goto err;
+
+	/* Register as a remoteproc device */
+	err = rproc_add(rproc);
+	if (err) {
+		dev_err(dev, "registration of xp70 remoteproc failed\n");
+		goto err;
+	}
+
+	dev_dbg(dev, "XP70 rproc init successful\n");
+	return rproc;
+
+err:
+	rproc_put(rproc);
+	return ERR_PTR(err);
+}
+EXPORT_SYMBOL(xp70_rproc_alloc);
+
+/**
+  * xp70_rproc_put - put xp70 rproc resources
+  * @xp70_rproc: Pointer to the st_xp70_rproc struct
+  *
+  * Function for calling respective _put() functions on
+  * xp70_rproc resources.
+  *
+  * Returns rproc pointer or PTR_ERR() on error.
+  */
+void xp70_rproc_put(struct st_xp70_rproc *xp70_rproc)
+{
+	int clk;
+
+	if (!xp70_rproc)
+		return;
+
+	rproc_put(xp70_rproc->rproc);
+
+	for (clk = 0; clk < XP70_MAX_CLK && xp70_rproc->clks[clk]; clk++)
+		clk_put(xp70_rproc->clks[clk]);
+
+}
+EXPORT_SYMBOL(xp70_rproc_put);
+
+MODULE_AUTHOR("Peter Griffin");
+MODULE_DESCRIPTION("STMicroelectronics XP70 rproc driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/remoteproc/st_xp70_rproc.h b/include/linux/remoteproc/st_xp70_rproc.h
new file mode 100644
index 0000000..3aba2de
--- /dev/null
+++ b/include/linux/remoteproc/st_xp70_rproc.h
@@ -0,0 +1,56 @@
+/*
+ * st_xp70_rproc.h
+ *
+ * Copyright (C) 2016 STMicroelectronics
+ * Author: Peter Griffin <peter.griffin@xxxxxxxxxx>
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+#ifndef _ST_XP70_H
+#define _ST_XP70_H
+
+#define XP70_MEM_MAX 2
+#define XP70_MAX_CLK 4
+#define NAME_SZ 10
+
+enum {
+	DMEM,
+	IMEM,
+};
+
+/**
+ * struct xp70_mem - xp70 internal memory structure
+ * @cpu_addr: MPU virtual address of the memory region
+ * @bus_addr: Bus address used to access the memory region
+ * @dev_addr: Device address from Wakeup M3 view
+ * @size: Size of the memory region
+ */
+struct xp70_mem {
+	void __iomem *cpu_addr;
+	phys_addr_t bus_addr;
+	u32 dev_addr;
+	size_t size;
+	struct resource *io_res;
+};
+
+/**
+ * struct st_xp70_rproc - XP70 slim core
+ * @rproc: rproc handle
+ * @pdev: pointer to platform device
+ * @mem: xp70 memory information
+ * @slimcore: xp70 slimcore regs
+ * @peri: xp70 peripheral regs
+ * @clks: xp70 clocks
+ */
+struct st_xp70_rproc {
+	struct rproc *rproc;
+	struct platform_device *pdev;
+	struct xp70_mem mem[XP70_MEM_MAX];
+	void __iomem *slimcore;
+	void __iomem *peri;
+	struct clk *clks[XP70_MAX_CLK];
+};
+
+struct rproc *xp70_rproc_alloc(struct platform_device *pdev, char *fw_name);
+void xp70_rproc_put(struct st_xp70_rproc *xp70_rproc);
+
+#endif
-- 
1.9.1