--- /dev/null
+/*
+ * ST's Remote Processor Control Driver
+ *
+ * Copyright (C) 2015 STMicroelectronics - All Rights Reserved
+ *
+ * Author: Ludovic Barre <ludovic.barre@st.com>
+ *
+ * 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 <ludovic.barre@st.com>");
+MODULE_LICENSE("GPL v2");
projects / cascardo / linux.git / commitdiff