remoteproc: st_slim_rproc: add a slimcore rproc driver

slim core is used as a basis for many IPs in the STi
chipsets such as fdma and demux. To avoid duplicating
the elf loading code in each device driver a slim
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 slim core.
The device driver can call slim_rproc_alloc() to allocate
a slim rproc and slim_rproc_put() when finished.

This driver takes care of ioremapping the slim
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 slim_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 slim
core once the firmware has been loaded. This has been tested
successfully with fdma driver.

Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

1 files changed, 364 insertions, 0 deletions

diff --git a/drivers/remoteproc/st_slim_rproc.c b/drivers/remoteproc/st_slim_rproc.c
new file mode 100644
index 000000000000..1484e9717946
--- /dev/null
+++ b/drivers/remoteproc/st_slim_rproc.c
@@ -0,0 +1,364 @@
+/*
+ * SLIM core rproc driver
+ *
+ * Copyright (C) 2016 STMicroelectronics
+ *
+ * Author: Peter Griffin <peter.griffin@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/clk.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_slim_rproc.h>
+#include "remoteproc_internal.h"
+
+/* SLIM core registers */
+#define SLIM_ID_OFST		0x0
+#define SLIM_VER_OFST		0x4
+
+#define SLIM_EN_OFST		0x8
+#define SLIM_EN_RUN			BIT(0)
+
+#define SLIM_CLK_GATE_OFST	0xC
+#define SLIM_CLK_GATE_DIS		BIT(0)
+#define SLIM_CLK_GATE_RESET		BIT(2)
+
+#define SLIM_SLIM_PC_OFST	0x20
+
+/* DMEM registers */
+#define SLIM_REV_ID_OFST	0x0
+#define SLIM_REV_ID_MIN_MASK		GENMASK(15, 8)
+#define SLIM_REV_ID_MIN(id)		((id & SLIM_REV_ID_MIN_MASK) >> 8)
+#define SLIM_REV_ID_MAJ_MASK		GENMASK(23, 16)
+#define SLIM_REV_ID_MAJ(id)		((id & SLIM_REV_ID_MAJ_MASK) >> 16)
+
+
+/* peripherals registers */
+#define SLIM_STBUS_SYNC_OFST	0xF88
+#define SLIM_STBUS_SYNC_DIS		BIT(0)
+
+#define SLIM_INT_SET_OFST	0xFD4
+#define SLIM_INT_CLR_OFST	0xFD8
+#define SLIM_INT_MASK_OFST	0xFDC
+
+#define SLIM_CMD_CLR_OFST	0xFC8
+#define SLIM_CMD_MASK_OFST	0xFCC
+
+static const char *mem_names[ST_SLIM_MEM_MAX] = {
+	[ST_SLIM_DMEM]	= "dmem",
+	[ST_SLIM_IMEM]	= "imem",
+};
+
+static int slim_clk_get(struct st_slim_rproc *slim_rproc, struct device *dev)
+{
+	int clk, err;
+
+	for (clk = 0; clk < ST_SLIM_MAX_CLK; clk++) {
+		slim_rproc->clks[clk] = of_clk_get(dev->of_node, clk);
+		if (IS_ERR(slim_rproc->clks[clk])) {
+			err = PTR_ERR(slim_rproc->clks[clk]);
+			if (err == -EPROBE_DEFER)
+				goto err_put_clks;
+			slim_rproc->clks[clk] = NULL;
+			break;
+		}
+	}
+
+	return 0;
+
+err_put_clks:
+	while (--clk >= 0)
+		clk_put(slim_rproc->clks[clk]);
+
+	return err;
+}
+
+static void slim_clk_disable(struct st_slim_rproc *slim_rproc)
+{
+	int clk;
+
+	for (clk = 0; clk < ST_SLIM_MAX_CLK && slim_rproc->clks[clk]; clk++)
+		clk_disable_unprepare(slim_rproc->clks[clk]);
+}
+
+static int slim_clk_enable(struct st_slim_rproc *slim_rproc)
+{
+	int clk, ret;
+
+	for (clk = 0; clk < ST_SLIM_MAX_CLK && slim_rproc->clks[clk]; clk++) {
+		ret = clk_prepare_enable(slim_rproc->clks[clk]);
+		if (ret)
+			goto err_disable_clks;
+	}
+
+	return 0;
+
+err_disable_clks:
+	while (--clk >= 0)
+		clk_disable_unprepare(slim_rproc->clks[clk]);
+
+	return ret;
+}
+
+/*
+ * Remoteproc slim specific device handlers
+ */
+static int slim_rproc_start(struct rproc *rproc)
+{
+	struct device *dev = &rproc->dev;
+	struct st_slim_rproc *slim_rproc = rproc->priv;
+	unsigned long hw_id, hw_ver, fw_rev;
+	u32 val;
+
+	/* disable CPU pipeline clock & reset CPU pipeline */
+	val = SLIM_CLK_GATE_DIS | SLIM_CLK_GATE_RESET;
+	writel(val, slim_rproc->slimcore + SLIM_CLK_GATE_OFST);
+
+	/* disable SLIM core STBus sync */
+	writel(SLIM_STBUS_SYNC_DIS, slim_rproc->peri + SLIM_STBUS_SYNC_OFST);
+
+	/* enable cpu pipeline clock */
+	writel(!SLIM_CLK_GATE_DIS,
+		slim_rproc->slimcore + SLIM_CLK_GATE_OFST);
+
+	/* clear int & cmd mailbox */
+	writel(~0U, slim_rproc->peri + SLIM_INT_CLR_OFST);
+	writel(~0U, slim_rproc->peri + SLIM_CMD_CLR_OFST);
+
+	/* enable all channels cmd & int */
+	writel(~0U, slim_rproc->peri + SLIM_INT_MASK_OFST);
+	writel(~0U, slim_rproc->peri + SLIM_CMD_MASK_OFST);
+
+	/* enable cpu */
+	writel(SLIM_EN_RUN, slim_rproc->slimcore + SLIM_EN_OFST);
+
+	hw_id = readl_relaxed(slim_rproc->slimcore + SLIM_ID_OFST);
+	hw_ver = readl_relaxed(slim_rproc->slimcore + SLIM_VER_OFST);
+
+	fw_rev = readl(slim_rproc->mem[ST_SLIM_DMEM].cpu_addr +
+			SLIM_REV_ID_OFST);
+
+	dev_info(dev, "fw rev:%ld.%ld on SLIM %ld.%ld\n",
+		 SLIM_REV_ID_MAJ(fw_rev), SLIM_REV_ID_MIN(fw_rev),
+		 hw_id, hw_ver);
+
+	return 0;
+}
+
+static int slim_rproc_stop(struct rproc *rproc)
+{
+	struct st_slim_rproc *slim_rproc = rproc->priv;
+	u32 val;
+
+	/* mask all (cmd & int) channels */
+	writel(0UL, slim_rproc->peri + SLIM_INT_MASK_OFST);
+	writel(0UL, slim_rproc->peri + SLIM_CMD_MASK_OFST);
+
+	/* disable cpu pipeline clock */
+	writel(SLIM_CLK_GATE_DIS, slim_rproc->slimcore + SLIM_CLK_GATE_OFST);
+
+	writel(!SLIM_EN_RUN, slim_rproc->slimcore + SLIM_EN_OFST);
+
+	val = readl(slim_rproc->slimcore + SLIM_EN_OFST);
+	if (val & SLIM_EN_RUN)
+		dev_warn(&rproc->dev, "Failed to disable SLIM");
+
+	dev_dbg(&rproc->dev, "slim stopped\n");
+
+	return 0;
+}
+
+static void *slim_rproc_da_to_va(struct rproc *rproc, u64 da, int len)
+{
+	struct st_slim_rproc *slim_rproc = rproc->priv;
+	void *va = NULL;
+	int i;
+
+	for (i = 0; i < ST_SLIM_MEM_MAX; i++) {
+		if (da != slim_rproc->mem[i].bus_addr)
+			continue;
+
+		if (len <= slim_rproc->mem[i].size) {
+			/* __force to make sparse happy with type conversion */
+			va = (__force void *)slim_rproc->mem[i].cpu_addr;
+			break;
+		}
+	}
+
+	dev_dbg(&rproc->dev, "da = 0x%llx len = 0x%x va = 0x%p\n", da, len, va);
+
+	return va;
+}
+
+static struct rproc_ops slim_rproc_ops = {
+	.start		= slim_rproc_start,
+	.stop		= slim_rproc_stop,
+	.da_to_va       = slim_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 *slim_rproc_find_rsc_table(struct rproc *rproc,
+					       const struct firmware *fw,
+					       int *tablesz)
+{
+	*tablesz = sizeof(empty_rsc_tbl);
+	return &empty_rsc_tbl;
+}
+
+static struct rproc_fw_ops slim_rproc_fw_ops = {
+	.find_rsc_table = slim_rproc_find_rsc_table,
+};
+
+/**
+ * st_slim_rproc_alloc() - allocate and initialise slim rproc
+ * @pdev: Pointer to the platform_device struct
+ * @fw_name: Name of firmware for rproc to use
+ *
+ * Function for allocating and initialising a slim rproc for use by
+ * device drivers whose IP is based around the SLIM core. It
+ * obtains and enables any clocks required by the SLIM core and also
+ * ioremaps the various IO.
+ *
+ * Returns st_slim_rproc pointer or PTR_ERR() on error.
+ */
+
+struct st_slim_rproc *st_slim_rproc_alloc(struct platform_device *pdev,
+				char *fw_name)
+{
+	struct device *dev = &pdev->dev;
+	struct st_slim_rproc *slim_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 (!fw_name)
+		return ERR_PTR(-EINVAL);
+
+	if (!of_device_is_compatible(np, "st,slim-rproc"))
+		return ERR_PTR(-EINVAL);
+
+	rproc = rproc_alloc(dev, np->name, &slim_rproc_ops,
+			fw_name, sizeof(*slim_rproc));
+	if (!rproc)
+		return ERR_PTR(-ENOMEM);
+
+	rproc->has_iommu = false;
+
+	slim_rproc = rproc->priv;
+	slim_rproc->rproc = rproc;
+
+	elf_ops = rproc->fw_ops;
+	/* Use some generic elf ops */
+	slim_rproc_fw_ops.load = elf_ops->load;
+	slim_rproc_fw_ops.sanity_check = elf_ops->sanity_check;
+
+	rproc->fw_ops = &slim_rproc_fw_ops;
+
+	/* get imem and dmem */
+	for (i = 0; i < ARRAY_SIZE(mem_names); i++) {
+		res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+						mem_names[i]);
+
+		slim_rproc->mem[i].cpu_addr = devm_ioremap_resource(dev, res);
+		if (IS_ERR(slim_rproc->mem[i].cpu_addr)) {
+			dev_err(&pdev->dev, "devm_ioremap_resource failed\n");
+			err = PTR_ERR(slim_rproc->mem[i].cpu_addr);
+			goto err;
+		}
+		slim_rproc->mem[i].bus_addr = res->start;
+		slim_rproc->mem[i].size = resource_size(res);
+	}
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "slimcore");
+	slim_rproc->slimcore = devm_ioremap_resource(dev, res);
+	if (IS_ERR(slim_rproc->slimcore)) {
+		dev_err(&pdev->dev, "failed to ioremap slimcore IO\n");
+		err = PTR_ERR(slim_rproc->slimcore);
+		goto err;
+	}
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "peripherals");
+	slim_rproc->peri = devm_ioremap_resource(dev, res);
+	if (IS_ERR(slim_rproc->peri)) {
+		dev_err(&pdev->dev, "failed to ioremap peripherals IO\n");
+		err = PTR_ERR(slim_rproc->peri);
+		goto err;
+	}
+
+	err = slim_clk_get(slim_rproc, dev);
+	if (err)
+		goto err;
+
+	err = slim_clk_enable(slim_rproc);
+	if (err) {
+		dev_err(dev, "Failed to enable clocks\n");
+		goto err_clk_put;
+	}
+
+	/* Register as a remoteproc device */
+	err = rproc_add(rproc);
+	if (err) {
+		dev_err(dev, "registration of slim remoteproc failed\n");
+		goto err_clk_dis;
+	}
+
+	return slim_rproc;
+
+err_clk_dis:
+	slim_clk_disable(slim_rproc);
+err_clk_put:
+	for (i = 0; i < ST_SLIM_MAX_CLK && slim_rproc->clks[i]; i++)
+		clk_put(slim_rproc->clks[i]);
+err:
+	rproc_put(rproc);
+	return ERR_PTR(err);
+}
+EXPORT_SYMBOL(st_slim_rproc_alloc);
+
+/**
+  * st_slim_rproc_put() - put slim rproc resources
+  * @slim_rproc: Pointer to the st_slim_rproc struct
+  *
+  * Function for calling respective _put() functions on slim_rproc resources.
+  *
+  */
+void st_slim_rproc_put(struct st_slim_rproc *slim_rproc)
+{
+	int clk;
+
+	if (!slim_rproc)
+		return;
+
+	slim_clk_disable(slim_rproc);
+
+	for (clk = 0; clk < ST_SLIM_MAX_CLK && slim_rproc->clks[clk]; clk++)
+		clk_put(slim_rproc->clks[clk]);
+
+	rproc_del(slim_rproc->rproc);
+	rproc_put(slim_rproc->rproc);
+}
+EXPORT_SYMBOL(st_slim_rproc_put);
+
+MODULE_AUTHOR("Peter Griffin <peter.griffin@linaro.org>");
+MODULE_DESCRIPTION("STMicroelectronics SLIM core rproc driver");
+MODULE_LICENSE("GPL v2");