[PATCH 3/3] remoteproc: wkup_m3: Add wkup_m3 remote proc driver

[Dave Gerlach]

Add a remoteproc driver to load the firmware for and boot the wkup_m3
present on am33xx. The wkup_m3 is an integrated Cortex M3 that allows
the SoC to enter the lowest possible power state by taking control from
the MPU after it has gone into its own low power state and shutting off
any additional peripherals.

The driver expects a resource table to be present in the wkup_m3
firmware to define the required memory resources needed by the wkup_m3,
at least the data memory so that the firmware can be copied to the proper
place for execution.

Signed-off-by: Dave Gerlach <d-gerlach at ti.com>
---
 drivers/remoteproc/Kconfig         |  12 +++
 drivers/remoteproc/Makefile        |   1 +
 drivers/remoteproc/wkup_m3_rproc.c | 175 +++++++++++++++++++++++++++++++++++++
 3 files changed, 188 insertions(+)
 create mode 100644 drivers/remoteproc/wkup_m3_rproc.c

diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
index 5e343ba..7fbdb53 100644
--- a/drivers/remoteproc/Kconfig
+++ b/drivers/remoteproc/Kconfig
@@ -41,6 +41,18 @@ config STE_MODEM_RPROC
 	  This can be either built-in or a loadable module.
 	  If unsure say N.
 
+config WKUP_M3_RPROC
+	bool "AM33xx wkup-m3 remoteproc support"
+	depends on SOC_AM33XX
+	select REMOTEPROC
+	help
+	  Say y here to support AM33xx wkup-m3.
+
+	  Required for Suspend-to-ram and CPUIdle on AM33xx. Allows for
+	  loading of firmware of CM3 PM coprocessor that is present
+	  on AM33xx family of SoCs
+	  If unsure say N.
+
 config DA8XX_REMOTEPROC
 	tristate "DA8xx/OMAP-L13x remoteproc support"
 	depends on ARCH_DAVINCI_DA8XX
diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile
index ac2ff75..81b04d1 100644
--- a/drivers/remoteproc/Makefile
+++ b/drivers/remoteproc/Makefile
@@ -9,4 +9,5 @@ remoteproc-y				+= remoteproc_virtio.o
 remoteproc-y				+= remoteproc_elf_loader.o
 obj-$(CONFIG_OMAP_REMOTEPROC)		+= omap_remoteproc.o
 obj-$(CONFIG_STE_MODEM_RPROC)	 	+= ste_modem_rproc.o
+obj-$(CONFIG_WKUP_M3_RPROC)		+= wkup_m3_rproc.o
 obj-$(CONFIG_DA8XX_REMOTEPROC)		+= da8xx_remoteproc.o
diff --git a/drivers/remoteproc/wkup_m3_rproc.c b/drivers/remoteproc/wkup_m3_rproc.c
new file mode 100644
index 0000000..8686ca2
--- /dev/null
+++ b/drivers/remoteproc/wkup_m3_rproc.c
@@ -0,0 +1,175 @@
+/*
+ * AMx3 Wkup M3 Remote Processor driver
+ *
+ * Copyright (C) 2014 Texas Instruments, Inc.
+ *
+ * Dave Gerlach <d-gerlach at ti.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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/remoteproc.h>
+
+#include <linux/platform_data/wkup_m3.h>
+
+#include "remoteproc_internal.h"
+
+struct wkup_m3_rproc {
+	struct rproc *rproc;
+	struct platform_device *pdev;
+};
+
+static int wkup_m3_rproc_start(struct rproc *rproc)
+{
+	struct wkup_m3_rproc *m3_rproc = rproc->priv;
+	struct platform_device *pdev = m3_rproc->pdev;
+	struct device *dev = &pdev->dev;
+	struct wkup_m3_platform_data *pdata = dev->platform_data;
+	int ret;
+
+	ret = pdata->deassert_reset(pdev, pdata->reset_name);
+	if (ret) {
+		dev_err(dev, "Unable to reset wkup_m3!\n");
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int wkup_m3_rproc_stop(struct rproc *rproc)
+{
+	struct wkup_m3_rproc *m3_rproc = rproc->priv;
+	struct platform_device *pdev = m3_rproc->pdev;
+	struct device *dev = &pdev->dev;
+	struct wkup_m3_platform_data *pdata = dev->platform_data;
+	int ret;
+
+	ret = pdata->assert_reset(pdev, pdata->reset_name);
+	if (ret) {
+		dev_err(dev, "Unable to assert reset of wkup_m3!\n");
+		return -ENODEV;
+	}
+	return 0;
+}
+
+static struct rproc_ops wkup_m3_rproc_ops = {
+	.start		= wkup_m3_rproc_start,
+	.stop		= wkup_m3_rproc_stop,
+};
+
+static const struct of_device_id wkup_m3_rproc_of_match[] = {
+	{
+		.compatible = "ti,am3353-wkup-m3",
+		.data = (void *)"am335x-pm-firmware.elf",
+	},
+	{},
+};
+
+static int wkup_m3_rproc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	const char *fw_name;
+	struct wkup_m3_platform_data *pdata = dev->platform_data;
+	struct wkup_m3_rproc *m3_rproc;
+	const struct of_device_id *match;
+	struct rproc *rproc;
+	int ret;
+
+	if (!(pdata && pdata->deassert_reset && pdata->assert_reset &&
+	      pdata->reset_name)) {
+		dev_err(dev, "Platform data missing!\n");
+		return -ENODEV;
+	}
+
+	match = of_match_device(wkup_m3_rproc_of_match, &pdev->dev);
+	if (!match)
+		return -ENODEV;
+	fw_name = (char *)match->data;
+
+	pm_runtime_enable(&pdev->dev);
+
+	ret = pm_runtime_get_sync(&pdev->dev);
+	if (IS_ERR_VALUE(ret)) {
+		dev_err(&pdev->dev, "pm_runtime_get_sync() failed\n");
+		return ret;
+	}
+
+	rproc = rproc_alloc(dev, "wkup_m3", &wkup_m3_rproc_ops,
+			    fw_name, sizeof(*m3_rproc));
+	if (!rproc)
+		return -ENOMEM;
+
+	m3_rproc = rproc->priv;
+	m3_rproc->rproc = rproc;
+	m3_rproc->pdev = pdev;
+
+	dev_set_drvdata(dev, rproc);
+
+	/* Register as a remoteproc device */
+	ret = rproc_add(rproc);
+	if (ret) {
+		dev_err(dev, "rproc_add failed\n");
+		goto err;
+	}
+
+	return 0;
+
+err:
+	rproc_put(rproc);
+	pm_runtime_put_sync(&pdev->dev);
+	return ret;
+}
+
+static int wkup_m3_rproc_remove(struct platform_device *pdev)
+{
+	struct rproc *rproc = platform_get_drvdata(pdev);
+
+	rproc_del(rproc);
+	rproc_put(rproc);
+	pm_runtime_put_sync(&pdev->dev);
+
+	return 0;
+}
+
+static int wkup_m3_rpm_suspend(struct device *dev)
+{
+	return -EBUSY;
+}
+
+static int wkup_m3_rpm_resume(struct device *dev)
+{
+	return 0;
+}
+
+static const struct dev_pm_ops wkup_m3_rproc_pm_ops = {
+	SET_RUNTIME_PM_OPS(wkup_m3_rpm_suspend, wkup_m3_rpm_resume, NULL)
+};
+
+static struct platform_driver wkup_m3_rproc_driver = {
+	.probe = wkup_m3_rproc_probe,
+	.remove = wkup_m3_rproc_remove,
+	.driver = {
+		.name = "wkup_m3",
+		.of_match_table = wkup_m3_rproc_of_match,
+		.pm = &wkup_m3_rproc_pm_ops,
+	},
+};
+
+module_platform_driver(wkup_m3_rproc_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("wkup m3 remote processor control driver");
-- 
2.1.0