[v2,02/10] soc: ti: pruss: add a misc driver for PRUSS in TI SoCs

diff --git a/drivers/soc/ti/Kconfig b/drivers/soc/ti/Kconfig
index e4f8834448..19bce14c05 100644
--- a/drivers/soc/ti/Kconfig
+++ b/drivers/soc/ti/Kconfig
@@ -23,4 +23,16 @@  config TI_KEYSTONE_SERDES
 	 SerDes driver for Keystone SoC used for ethernet support on TI
 	 K2 platforms.
 
+config TI_PRUSS
+	bool "Support for TI's K3 based Pruss driver"
+	depends on DM
+	depends on ARCH_K3
+	depends on OF_CONTROL
+	depends on SYSCON
+	help
+	  Support for TI PRU-ICSSG subsystem.
+
+          Currently supported on AM65xx SoCs. Say Y here to support the
+	  Programmable Realtime Unit (PRU).
+
 endif # SOC_TI
diff --git a/drivers/soc/ti/Makefile b/drivers/soc/ti/Makefile
index 4ec04ee125..34f80aad29 100644
--- a/drivers/soc/ti/Makefile
+++ b/drivers/soc/ti/Makefile
@@ -2,3 +2,4 @@ 
 
 obj-$(CONFIG_TI_K3_NAVSS_RINGACC)	+= k3-navss-ringacc.o
 obj-$(CONFIG_TI_KEYSTONE_SERDES)	+= keystone_serdes.o
+obj-$(CONFIG_TI_PRUSS)	+= pruss.o
diff --git a/drivers/soc/ti/pruss.c b/drivers/soc/ti/pruss.c
new file mode 100644
index 0000000000..059ae11805
--- /dev/null
+++ b/drivers/soc/ti/pruss.c
@@ -0,0 +1,152 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PRU-ICSS platform driver for various TI SoCs
+ *
+ * Copyright (C) 2020 Texas Instruments Incorporated - http://www.ti.com/
+ *	Keerthy <j-keerthy at ti.com>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <dm/device_compat.h>
+#include <dm/of_access.h>
+#include <errno.h>
+#include <clk.h>
+#include <reset.h>
+#include <regmap.h>
+#include <syscon.h>
+#include <asm/io.h>
+#include <power-domain.h>
+#include <ti-pruss.h>
+
+#define PRUSS_CFG_IEPCLK	0x30
+#define ICSSG_CFG_CORE_SYNC	0x3c
+
+#define ICSSG_TASK_MGR_OFFSET	0x2a000
+
+/* PRUSS_IEPCLK register bits */
+#define PRUSS_IEPCLK_IEP_OCP_CLK_EN		BIT(0)
+
+/* ICSSG CORE_SYNC register bits */
+#define ICSSG_CORE_VBUSP_SYNC_EN		BIT(0)
+
+/**
+ * enum pruss_mem - PRUSS memory range identifiers
+ */
+enum pruss_mem {
+	PRUSS_MEM_DRAM0 = 0,
+	PRUSS_MEM_DRAM1,
+	PRUSS_MEM_SHRD_RAM2,
+	PRUSS_MEM_MAX,
+};
+
+/*
+ * pruss_request_tm_region() - Request pruss for task manager region
+ * @dev:	corresponding k3 device
+ * @loc:	the task manager physical address
+ *
+ * Return: 0 if all goes good, else appropriate error message.
+ */
+int pruss_request_tm_region(struct udevice *dev, phys_addr_t *loc)
+{
+	struct pruss *priv;
+
+	priv = dev_get_priv(dev);
+	if (!priv || !priv->pruss_dram0)
+		return -EINVAL;
+
+	*loc = priv->pruss_dram0 + ICSSG_TASK_MGR_OFFSET;
+
+	return 0;
+}
+
+/*
+ * pruss_request_shrmem_region() - Request pruss for shared memory region
+ * @dev:	corresponding k3 device
+ * @loc:	the shared memory physical address
+ *
+ * Return: 0 if all goes good, else appropriate error message.
+ */
+int pruss_request_shrmem_region(struct udevice *dev, phys_addr_t *loc)
+{
+	struct pruss *priv;
+
+	priv = dev_get_priv(dev);
+	if (!priv || !priv->pruss_shrdram2)
+		return -EINVAL;
+
+	*loc = priv->pruss_shrdram2;
+
+	return 0;
+}
+
+/**
+ * pruss_probe() - Basic probe
+ * @dev:	corresponding k3 device
+ *
+ * Return: 0 if all goes good, else appropriate error message.
+ */
+static int pruss_probe(struct udevice *dev)
+{
+	struct pruss *priv;
+	int ret, idx;
+	ofnode sub_node, node, memories;
+	struct regmap *regmap_cfg;
+	struct udevice *syscon;
+
+	priv = dev_get_priv(dev);
+	node = dev_ofnode(dev);
+	sub_node = ofnode_find_subnode(node, "cfg");
+	memories = ofnode_find_subnode(node, "memories");
+
+	idx = ofnode_stringlist_search(memories, "reg-names", "dram0");
+	priv->pruss_dram0 = ofnode_get_addr_size_index(memories, idx,
+						       (u64 *)&priv->pruss_dram0sz);
+	idx = ofnode_stringlist_search(memories, "reg-names", "dram1");
+	priv->pruss_dram1 = ofnode_get_addr_size_index(memories, idx,
+						       (u64 *)&priv->pruss_dram1sz);
+	idx = ofnode_stringlist_search(memories, "reg-names", "shrdram2");
+	priv->pruss_shrdram2 = ofnode_get_addr_size_index(memories, idx,
+							  (u64 *)&priv->pruss_shrdram2sz);
+
+	ret = uclass_get_device_by_ofnode(UCLASS_SYSCON, sub_node,
+					  &syscon);
+
+	regmap_cfg = syscon_get_regmap(syscon);
+
+	/*
+	 * The CORE block uses two multiplexers to allow software to
+	 * select one of three source clocks (ICSSGn_CORE_CLK, ICSSGn_ICLK or
+	 * ICSSGn_IEP_CLK) for the final clock source of the CORE block.
+	 * The user needs to configure ICSSG_CORE_SYNC_REG[0] CORE_VBUSP_SYNC_EN
+	 * bit & ICSSG_IEPCLK_REG[0] IEP_OCP_CLK_EN bit in order to select the
+	 * clock source to the CORE block.
+	 */
+	ret = regmap_update_bits(regmap_cfg, ICSSG_CFG_CORE_SYNC,
+				 ICSSG_CORE_VBUSP_SYNC_EN,
+				 ICSSG_CORE_VBUSP_SYNC_EN);
+	if (ret)
+		return ret;
+	ret = regmap_update_bits(regmap_cfg, PRUSS_CFG_IEPCLK,
+				 PRUSS_IEPCLK_IEP_OCP_CLK_EN,
+				 PRUSS_IEPCLK_IEP_OCP_CLK_EN);
+	if (ret)
+		return ret;
+
+	dev_dbg(dev, "pruss successfully probed %s\n", dev->name);
+
+	return 0;
+}
+
+static const struct udevice_id pruss_ids[] = {
+	{ .compatible = "ti,am654-icssg" },
+	{}
+};
+
+U_BOOT_DRIVER(pruss) = {
+	.name = "pruss",
+	.of_match = pruss_ids,
+	.id = UCLASS_MISC,
+	.probe = pruss_probe,
+	.priv_auto_alloc_size = sizeof(struct pruss),
+};
diff --git a/include/ti-pruss.h b/include/ti-pruss.h
new file mode 100644
index 0000000000..dd36152578
--- /dev/null
+++ b/include/ti-pruss.h
@@ -0,0 +1,17 @@ 
+// SPDX-License-Identifier: GPL-2.0
+
+#ifndef __TI_PRUSS_H_
+#define __TI_PRUSS_H_
+
+struct pruss {
+	phys_addr_t pruss_dram0;
+	phys_addr_t pruss_dram1;
+	phys_addr_t pruss_shrdram2;
+	phys_size_t pruss_dram0sz;
+	phys_size_t pruss_dram1sz;
+	phys_size_t pruss_shrdram2sz;
+};
+
+int pruss_request_shrmem_region(struct udevice *dev, phys_addr_t *loc);
+int pruss_request_tm_region(struct udevice *dev, phys_addr_t *loc);
+#endif /* __TI_PRUSS_H_ */