remoteproc: Introduce K3 remoteproc driver

Add support for K3 based remoteproc driver that
communicates with TISCI to start start a remote processor.

Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>

doc/device-tree-bindings/remoteproc/k3-rproc.txt

@@ -0,0 +1,50 @@
+Texas Instruments' K3 Remote processor driver
+=============================================
+
+In K3 generation Socs, loading an image on any processing entity
+cannot be done directly from U-Boot. In order to load an image,
+remoteproc driver should communicate to SYSFW with a specific sequence.
+Also enable the timer required for this remotecore.
+
+Required properties:
+--------------------
+- compatible:		Shall be: "ti,am654-rproc"
+- reg:			base address of the remoteproc timer.
+- power-domains:	Should contain two sets of entries:
+			First set corresponds to pm domain of the
+			remotecore timer. Seconf entry corresponds to the
+			remoteproc to start.
+			This property is as per the binding,
+			doc/device-tree-bindings/power/ti,sci-pm-domain.txt
+- resets:		Should contain a phandle to a reset controller node
+			and an args specifier containing the remote code
+			device id and reset mask value. This is as per the
+			doc/device-tree-bindings/reset/ti,sci-reset.txt
+- ti,sci:		Phandle to TI-SCI compatible System controller node.
+- ti,sci-proc-id:	Processor id as identified by TISCI
+
+Optional properties:
+--------------------
+- assigned-clocks:	Should contain a phandle to clock node and an args
+			specifier containing the remote core device id and
+			the clock id within the remote core. This is as per
+			doc/device-tree-bindings/clock/ti,sci-clk.txt
+- assigned-clock-rates: One entry for each entry of assigned-clocks. This is
+			the frequency at which the corresponding clock needs
+			to be assigned.
+- ti,sci-host-id:	Host ID to which the processor control is transferred to
+
+Example:
+---------
+
+a53_0: a53@0 {
+	compatible = "ti,am654-rproc";
+	power-domains = <&k3_pds 61>,
+			<&k3_pds 202>;
+	resets = <&k3_reset 202 0>;
+	assigned-clocks = <&k3_clks 202 0>;
+	assigned-clock-rates = <800000000>;
+	ti,sci = <&dmsc>;
+	ti,sci-proc-id = <32>;
+	ti,sci-host-id = <10>;
+};

drivers/remoteproc/Kconfig

@@ -22,6 +22,15 @@ config K3_SYSTEM_CONTROLLER
 	help
 	  Say 'y' here to add support for TI' K3 System Controller.
 
+config REMOTEPROC_K3
+	bool "Support for TI's K3 based remoteproc driver"
+	select REMOTEPROC
+	depends on DM
+	depends on ARCH_K3
+	depends on OF_CONTROL
+	help
+	  Say 'y' here to add support for TI' K3 remoteproc driver.
+
 config REMOTEPROC_SANDBOX
 	bool "Support for Test processor for Sandbox"
 	select REMOTEPROC

drivers/remoteproc/Makefile

@@ -8,5 +8,6 @@ obj-$(CONFIG_REMOTEPROC) += rproc-uclass.o
 
 # Remote proc drivers - Please keep this list alphabetically sorted.
 obj-$(CONFIG_K3_SYSTEM_CONTROLLER) += k3_system_controller.o
+obj-$(CONFIG_REMOTEPROC_K3) += k3_rproc.o
 obj-$(CONFIG_REMOTEPROC_SANDBOX) += sandbox_testproc.o
 obj-$(CONFIG_REMOTEPROC_TI_POWER) += ti_power_proc.o

drivers/remoteproc/k3_rproc.c

@@ -0,0 +1,244 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Texas Instruments' K3 Remoteproc driver
+ *
+ * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
+ *	Lokesh Vutla <lokeshvutla@ti.com>
+ *
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <remoteproc.h>
+#include <errno.h>
+#include <clk.h>
+#include <reset.h>
+#include <asm/io.h>
+#include <power-domain.h>
+#include <linux/soc/ti/ti_sci_protocol.h>
+
+#define INVALID_ID	0xffff
+
+#define GTC_CNTCR_REG	0x0
+#define GTC_CNTR_EN	0x3
+
+/**
+ * struct k3_rproc_privdata - Structure representing Remote processor data.
+ * @rproc_pwrdmn:	rproc power domain data
+ * @rproc_rst:		rproc reset control data
+ * @sci:		Pointer to TISCI handle
+ * @gtc_base:		Timer base address.
+ * @proc_id:		TISCI processor ID
+ * @host_id:		TISCI host id to which the processor gets assigned to.
+ */
+struct k3_rproc_privdata {
+	struct power_domain rproc_pwrdmn;
+	struct power_domain gtc_pwrdmn;
+	struct reset_ctl rproc_rst;
+	const struct ti_sci_handle *sci;
+	void *gtc_base;
+	u16 proc_id;
+	u16 host_id;
+};
+
+/**
+ * k3_rproc_load() - Load up the Remote processor image
+ * @dev:	rproc device pointer
+ * @addr:	Address at which image is available
+ * @size:	size of the image
+ *
+ * Return: 0 if all goes good, else appropriate error message.
+ */
+static int k3_rproc_load(struct udevice *dev, ulong addr, ulong size)
+{
+	struct k3_rproc_privdata *rproc = dev_get_priv(dev);
+	const struct ti_sci_proc_ops *pops = &rproc->sci->ops.proc_ops;
+	int ret;
+
+	dev_dbg(dev, "%s addr = 0x%lx, size = 0x%lx\n", __func__, addr, size);
+
+	/* request for the processor */
+	ret = pops->proc_request(rproc->sci, rproc->proc_id);
+	if (ret) {
+		dev_err(dev, "Requesting processor failed %d\n", ret);
+		return ret;
+	}
+
+	ret = pops->set_proc_boot_cfg(rproc->sci, rproc->proc_id, addr, 0, 0);
+	if (ret) {
+		dev_err(dev, "set_proc_boot_cfg failed %d\n", ret);
+		return ret;
+	}
+
+	dev_dbg(dev, "%s: rproc successfully loaded\n", __func__);
+
+	return 0;
+}
+
+/**
+ * k3_rproc_start() - Start the remote processor
+ * @dev:	rproc device pointer
+ *
+ * Return: 0 if all went ok, else return appropriate error
+ */
+static int k3_rproc_start(struct udevice *dev)
+{
+	struct k3_rproc_privdata *rproc = dev_get_priv(dev);
+	const struct ti_sci_proc_ops *pops = &rproc->sci->ops.proc_ops;
+	int ret;
+
+	dev_dbg(dev, "%s\n", __func__);
+
+	ret = power_domain_on(&rproc->gtc_pwrdmn);
+	if (ret) {
+		dev_err(dev, "power_domain_on() failed: %d\n", ret);
+		return ret;
+	}
+
+	/* Enable the timer before starting remote core */
+	writel(GTC_CNTR_EN, rproc->gtc_base + GTC_CNTCR_REG);
+
+	/*
+	 * Setting the right clock frequency would have taken care by
+	 * assigned-clock-rates during the device probe. So no need to
+	 * set the frequency again here.
+	 */
+	ret = power_domain_on(&rproc->rproc_pwrdmn);
+	if (ret) {
+		dev_err(dev, "power_domain_on() failed: %d\n", ret);
+		return ret;
+	}
+
+	if (rproc->host_id != INVALID_ID) {
+		ret = pops->proc_handover(rproc->sci, rproc->proc_id,
+					  rproc->host_id);
+		if (ret) {
+			dev_err(dev, "Handover processor failed %d\n", ret);
+			return ret;
+		}
+	} else {
+		ret = pops->proc_release(rproc->sci, rproc->proc_id);
+		if (ret) {
+			dev_err(dev, "Processor release failed %d\n", ret);
+			return ret;
+		}
+	}
+
+	dev_dbg(dev, "%s: rproc successfully started\n", __func__);
+
+	return 0;
+}
+
+/**
+ * k3_rproc_init() - Initialize the remote processor
+ * @dev:	rproc device pointer
+ *
+ * Return: 0 if all went ok, else return appropriate error
+ */
+static int k3_rproc_init(struct udevice *dev)
+{
+	dev_dbg(dev, "%s\n", __func__);
+
+	/* Enable the module */
+	dev_dbg(dev, "%s: rproc successfully initialized\n", __func__);
+
+	return 0;
+}
+
+static const struct dm_rproc_ops k3_rproc_ops = {
+	.init = k3_rproc_init,
+	.load = k3_rproc_load,
+	.start = k3_rproc_start,
+};
+
+/**
+ * k3_of_to_priv() - generate private data from device tree
+ * @dev:	corresponding k3 remote processor device
+ * @priv:	pointer to driver specific private data
+ *
+ * Return: 0 if all goes good, else appropriate error message.
+ */
+static int k3_rproc_of_to_priv(struct udevice *dev,
+			       struct k3_rproc_privdata *rproc)
+{
+	int ret;
+
+	dev_dbg(dev, "%s\n", __func__);
+
+	ret = power_domain_get_by_index(dev, &rproc->rproc_pwrdmn, 1);
+	if (ret) {
+		dev_err(dev, "power_domain_get() failed: %d\n", ret);
+		return ret;
+	}
+
+	ret = power_domain_get_by_index(dev, &rproc->gtc_pwrdmn, 0);
+	if (ret) {
+		dev_err(dev, "power_domain_get() failed: %d\n", ret);
+		return ret;
+	}
+
+	ret = reset_get_by_index(dev, 0, &rproc->rproc_rst);
+	if (ret) {
+		dev_err(dev, "reset_get() failed: %d\n", ret);
+		return ret;
+	}
+
+	rproc->sci = ti_sci_get_by_phandle(dev, "ti,sci");
+	if (IS_ERR(rproc->sci)) {
+		dev_err(dev, "ti_sci get failed: %d\n", ret);
+		return PTR_ERR(rproc->sci);
+	}
+
+	rproc->gtc_base = dev_read_addr_ptr(dev);
+	if (!rproc->gtc_base) {
+		dev_err(dev, "Get address failed\n");
+		return -ENODEV;
+	}
+
+	rproc->proc_id = dev_read_u32_default(dev, "ti,sci-proc-id",
+					      INVALID_ID);
+	rproc->host_id = dev_read_u32_default(dev, "ti,sci-host-id",
+					      INVALID_ID);
+
+	return 0;
+}
+
+/**
+ * k3_rproc_probe() - Basic probe
+ * @dev:	corresponding k3 remote processor device
+ *
+ * Return: 0 if all goes good, else appropriate error message.
+ */
+static int k3_rproc_probe(struct udevice *dev)
+{
+	struct k3_rproc_privdata *priv;
+	int ret;
+
+	dev_dbg(dev, "%s\n", __func__);
+
+	priv = dev_get_priv(dev);
+
+	ret = k3_rproc_of_to_priv(dev, priv);
+	if (ret) {
+		dev_dbg(dev, "%s: Probe failed with error %d\n", __func__, ret);
+		return ret;
+	}
+
+	dev_dbg(dev, "Remoteproc successfully probed\n");
+
+	return 0;
+}
+
+static const struct udevice_id k3_rproc_ids[] = {
+	{ .compatible = "ti,am654-rproc"},
+	{}
+};
+
+U_BOOT_DRIVER(k3_rproc) = {
+	.name = "k3_rproc",
+	.of_match = k3_rproc_ids,
+	.id = UCLASS_REMOTEPROC,
+	.ops = &k3_rproc_ops,
+	.probe = k3_rproc_probe,
+	.priv_auto_alloc_size = sizeof(struct k3_rproc_privdata),
+};