remoteproc: Supply controller driver for ST's Remote Processors

Signed-off-by: Ludovic Barre <[e-mail]>
Signed-off-by: Lee Jones <[e-mail]>
Signed-off-by: Bjorn Andersson <[e-mail]>

drivers/remoteproc/Kconfig

···
 	  It's safe to say n here if you're not interested in multimedia
 	  offloading.
 
+config ST_REMOTEPROC
+	tristate "ST remoteproc support"
+	depends on ARCH_STI
+	select REMOTEPROC
+	help
+	  Say y here to support ST's adjunct processors via the remote
+	  processor framework.
+	  This can be either built-in or a loadable module.
+
 endmenu

drivers/remoteproc/Makefile

···
 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

drivers/remoteproc/st_remoteproc.c

···
+/*
+ * ST's Remote Processor Control Driver
+ *
+ * Copyright (C) 2015 STMicroelectronics - All Rights Reserved
+ *
+ * Author: Ludovic Barre <[e-mail]>
+ *
+ * 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/dma-mapping.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.h>
+#include <linux/of_device.h>
+#include <linux/of_reserved_mem.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/remoteproc.h>
+#include <linux/reset.h>
+
+struct st_rproc_config {
+	bool			sw_reset;
+	bool			pwr_reset;
+	unsigned long		bootaddr_mask;
+};
+
+struct st_rproc {
+	struct st_rproc_config	*config;
+	struct reset_control	*sw_reset;
+	struct reset_control	*pwr_reset;
+	struct clk		*clk;
+	u32			clk_rate;
+	struct regmap		*boot_base;
+	u32			boot_offset;
+};
+
+static int st_rproc_start(struct rproc *rproc)
+{
+	struct st_rproc *ddata = rproc->priv;
+	int err;
+
+	regmap_update_bits(ddata->boot_base, ddata->boot_offset,
+			   ddata->config->bootaddr_mask, rproc->bootaddr);
+
+	err = clk_enable(ddata->clk);
+	if (err) {
+		dev_err(&rproc->dev, "Failed to enable clock\n");
+		return err;
+	}
+
+	if (ddata->config->sw_reset) {
+		err = reset_control_deassert(ddata->sw_reset);
+		if (err) {
+			dev_err(&rproc->dev, "Failed to deassert S/W Reset\n");
+			goto sw_reset_fail;
+		}
+	}
+
+	if (ddata->config->pwr_reset) {
+		err = reset_control_deassert(ddata->pwr_reset);
+		if (err) {
+			dev_err(&rproc->dev, "Failed to deassert Power Reset\n");
+			goto pwr_reset_fail;
+		}
+	}
+
+	dev_info(&rproc->dev, "Started from 0x%x\n", rproc->bootaddr);
+
+	return 0;
+
+
+pwr_reset_fail:
+	if (ddata->config->pwr_reset)
+		reset_control_assert(ddata->sw_reset);
+sw_reset_fail:
+	clk_disable(ddata->clk);
+
+	return err;
+}
+
+static int st_rproc_stop(struct rproc *rproc)
+{
+	struct st_rproc *ddata = rproc->priv;
+	int sw_err = 0, pwr_err = 0;
+
+	if (ddata->config->sw_reset) {
+		sw_err = reset_control_assert(ddata->sw_reset);
+		if (sw_err)
+			dev_err(&rproc->dev, "Failed to assert S/W Reset\n");
+	}
+
+	if (ddata->config->pwr_reset) {
+		pwr_err = reset_control_assert(ddata->pwr_reset);
+		if (pwr_err)
+			dev_err(&rproc->dev, "Failed to assert Power Reset\n");
+	}
+
+	clk_disable(ddata->clk);
+
+	return sw_err ?: pwr_err;
+}
+
+static struct rproc_ops st_rproc_ops = {
+	.start		= st_rproc_start,
+	.stop		= st_rproc_stop,
+};
+
+/*
+ * Fetch state of the processor: 0 is off, 1 is on.
+ */
+static int st_rproc_state(struct platform_device *pdev)
+{
+	struct rproc *rproc = platform_get_drvdata(pdev);
+	struct st_rproc *ddata = rproc->priv;
+	int reset_sw = 0, reset_pwr = 0;
+
+	if (ddata->config->sw_reset)
+		reset_sw = reset_control_status(ddata->sw_reset);
+
+	if (ddata->config->pwr_reset)
+		reset_pwr = reset_control_status(ddata->pwr_reset);
+
+	if (reset_sw < 0 || reset_pwr < 0)
+		return -EINVAL;
+
+	return !reset_sw && !reset_pwr;
+}
+
+static const struct st_rproc_config st40_rproc_cfg = {
+	.sw_reset = true,
+	.pwr_reset = true,
+	.bootaddr_mask = GENMASK(28, 1),
+};
+
+static const struct st_rproc_config st231_rproc_cfg = {
+	.sw_reset = true,
+	.pwr_reset = false,
+	.bootaddr_mask = GENMASK(31, 6),
+};
+
+static const struct of_device_id st_rproc_match[] = {
+	{ .compatible = "st,st40-rproc", .data = &st40_rproc_cfg },
+	{ .compatible = "st,st231-rproc", .data = &st231_rproc_cfg },
+	{},
+};
+MODULE_DEVICE_TABLE(of, st_rproc_match);
+
+static int st_rproc_parse_dt(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct rproc *rproc = platform_get_drvdata(pdev);
+	struct st_rproc *ddata = rproc->priv;
+	struct device_node *np = dev->of_node;
+	int err;
+
+	if (ddata->config->sw_reset) {
+		ddata->sw_reset = devm_reset_control_get(dev, "sw_reset");
+		if (IS_ERR(ddata->sw_reset)) {
+			dev_err(dev, "Failed to get S/W Reset\n");
+			return PTR_ERR(ddata->sw_reset);
+		}
+	}
+
+	if (ddata->config->pwr_reset) {
+		ddata->pwr_reset = devm_reset_control_get(dev, "pwr_reset");
+		if (IS_ERR(ddata->pwr_reset)) {
+			dev_err(dev, "Failed to get Power Reset\n");
+			return PTR_ERR(ddata->pwr_reset);
+		}
+	}
+
+	ddata->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(ddata->clk)) {
+		dev_err(dev, "Failed to get clock\n");
+		return PTR_ERR(ddata->clk);
+	}
+
+	err = of_property_read_u32(np, "clock-frequency", &ddata->clk_rate);
+	if (err) {
+		dev_err(dev, "failed to get clock frequency\n");
+		return err;
+	}
+
+	ddata->boot_base = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
+	if (!ddata->boot_base) {
+		dev_err(dev, "Boot base not found\n");
+		return -EINVAL;
+	}
+
+	err = of_property_read_u32_index(np, "st,syscfg", 1,
+					 &ddata->boot_offset);
+	if (err) {
+		dev_err(dev, "Boot offset not found\n");
+		return -EINVAL;
+	}
+
+	err = of_reserved_mem_device_init(dev);
+	if (err) {
+		dev_err(dev, "Failed to obtain shared memory\n");
+		return err;
+	}
+
+	err = clk_prepare(ddata->clk);
+	if (err)
+		dev_err(dev, "failed to get clock\n");
+
+	return err;
+}
+
+static int st_rproc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	const struct of_device_id *match;
+	struct st_rproc *ddata;
+	struct device_node *np = dev->of_node;
+	struct rproc *rproc;
+	int enabled;
+	int ret;
+
+	match = of_match_device(st_rproc_match, dev);
+	if (!match || !match->data) {
+		dev_err(dev, "No device match found\n");
+		return -ENODEV;
+	}
+
+	rproc = rproc_alloc(dev, np->name, &st_rproc_ops, NULL, sizeof(*ddata));
+	if (!rproc)
+		return -ENOMEM;
+
+	rproc->has_iommu = false;
+	ddata = rproc->priv;
+	ddata->config = (struct st_rproc_config *)match->data;
+
+	platform_set_drvdata(pdev, rproc);
+
+	ret = st_rproc_parse_dt(pdev);
+	if (ret)
+		goto free_rproc;
+
+	enabled = st_rproc_state(pdev);
+	if (enabled < 0)
+		goto free_rproc;
+
+	if (enabled) {
+		atomic_inc(&rproc->power);
+		rproc->state = RPROC_RUNNING;
+	} else {
+		clk_set_rate(ddata->clk, ddata->clk_rate);
+	}
+
+	ret = rproc_add(rproc);
+	if (ret)
+		goto free_rproc;
+
+	return 0;
+
+free_rproc:
+	rproc_put(rproc);
+	return ret;
+}
+
+static int st_rproc_remove(struct platform_device *pdev)
+{
+	struct rproc *rproc = platform_get_drvdata(pdev);
+	struct st_rproc *ddata = rproc->priv;
+
+	rproc_del(rproc);
+
+	clk_disable_unprepare(ddata->clk);
+
+	of_reserved_mem_device_release(&pdev->dev);
+
+	rproc_put(rproc);
+
+	return 0;
+}
+
+static struct platform_driver st_rproc_driver = {
+	.probe = st_rproc_probe,
+	.remove = st_rproc_remove,
+	.driver = {
+		.name = "st-rproc",
+		.of_match_table = of_match_ptr(st_rproc_match),
+	},
+};
+module_platform_driver(st_rproc_driver);
+
+MODULE_DESCRIPTION("ST Remote Processor Control Driver");
+MODULE_AUTHOR("Ludovic Barre <[e-mail]>");
+MODULE_LICENSE("GPL v2");