[PATCH 2/3] ARM: bus: da8xx-syscfg: new driver

[Bartosz Golaszewski <bgolaszewski-rdvid1DuHRBWk0Htik3J/w@public.gmane.org>]

Create the driver for the da8xx System Configuration and implement
support for writing to the three Master Priority registers.

Signed-off-by: Bartosz Golaszewski <bgolaszewski-rdvid1DuHRBWk0Htik3J/w@public.gmane.org>
---
 .../devicetree/bindings/bus/ti,da850-syscfg.txt    |  63 +++++++
 drivers/bus/Kconfig                                |   8 +
 drivers/bus/Makefile                               |   2 +
 drivers/bus/da8xx-syscfg.c                         | 206 +++++++++++++++++++++
 4 files changed, 279 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/bus/ti,da850-syscfg.txt
 create mode 100644 drivers/bus/da8xx-syscfg.c

diff --git a/Documentation/devicetree/bindings/bus/ti,da850-syscfg.txt b/Documentation/devicetree/bindings/bus/ti,da850-syscfg.txt
new file mode 100644
index 0000000..07e5c38
--- /dev/null
+++ b/Documentation/devicetree/bindings/bus/ti,da850-syscfg.txt
@@ -0,0 +1,63 @@
+* Device tree bindings for Texas Instruments da8xx system configuration driver
+
+The system configuration (SYSCFG) module is a system-level module containing
+status and top level control logic required by the device. The system
+configuration module consists of a set of memory-mapped status and control
+registers, accessible by the CPU, supporting all of the following system
+features, and miscellaneous functions and operations.
+
+Documentation:
+OMAP-L138 (DA850) - http://www.ti.com/lit/ug/spruh82c/spruh82c.pdf
+
+Required properties:
+
+- compatible:		"ti,da850-syscfg"
+
+Optional properties:
+
+The below properties are used to specify the priority of master peripherals.
+They must be between 0-7 where 0 is the highest priority and 7 is the lowest.
+
+- ti,pri-arm-i:		ARM_I port priority.
+
+- ti,pri-arm-d:		ARM_D port priority.
+
+- ti,pri-upp:		uPP port priority.
+
+- ti,pri-sata:		SATA port priority.
+
+- ti,pri-pru0:		PRU0 port priority.
+
+- ti,pri-pru1:		PRU1 port priority.
+
+- ti,pri-edma30tc0:	EDMA3_0_TC0 port priority.
+
+- ti,pri-edma30tc1:	EDMA3_0_TC1 port priority.
+
+- ti,pri-edma31tc0:	EDMA3_1_TC0 port priority.
+
+- ti,pri-vpif-dma-0:	VPIF DMA0 port priority.
+
+- ti,pri-vpif-dma-1:	VPIF DMA1 port priority.
+
+- ti,pri-emac:		EMAC port priority.
+
+- ti,pri-usb0cfg:	USB0 CFG port priority.
+
+- ti,pri-usb0cdma:	USB0 CDMA port priority.
+
+- ti,pri-uhpi:		HPI port priority.
+
+- ti,pri-usb1:		USB1 port priority.
+
+- ti,pri-lcdc:		LCDC port priority.
+
+If any of the above properties is absent, the default value will be used as
+defined in the documentation.
+
+Example for da850-lcdk is shown below.
+
+mstpri {
+	compatible = "ti,da850-mstpri";
+	ti,pri-lcdc = 0;
+};
diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
index 5a2d47c..6276132 100644
--- a/drivers/bus/Kconfig
+++ b/drivers/bus/Kconfig
@@ -165,4 +165,12 @@ config VEXPRESS_CONFIG
 	help
 	  Platform configuration infrastructure for the ARM Ltd.
 	  Versatile Express.
+
+config DA8XX_SYSCFG
+	bool "TI da8xx system configuration driver"
+	depends on ARCH_DAVINCI_DA8XX
+	help
+	  Driver for Texas Instruments da8xx system configuration. Allows to
+	  adjust various SoC configuration options.
+
 endmenu
diff --git a/drivers/bus/Makefile b/drivers/bus/Makefile
index c6cfa6b..3cba66a 100644
--- a/drivers/bus/Makefile
+++ b/drivers/bus/Makefile
@@ -21,3 +21,5 @@ obj-$(CONFIG_SIMPLE_PM_BUS)	+= simple-pm-bus.o
 obj-$(CONFIG_TEGRA_ACONNECT)	+= tegra-aconnect.o
 obj-$(CONFIG_UNIPHIER_SYSTEM_BUS)	+= uniphier-system-bus.o
 obj-$(CONFIG_VEXPRESS_CONFIG)	+= vexpress-config.o
+
+obj-$(CONFIG_DA8XX_SYSCFG)	+= da8xx-syscfg.o
diff --git a/drivers/bus/da8xx-syscfg.c b/drivers/bus/da8xx-syscfg.c
new file mode 100644
index 0000000..8a2cb4f
--- /dev/null
+++ b/drivers/bus/da8xx-syscfg.c
@@ -0,0 +1,206 @@
+/*
+ * TI da8xx System Configuration driver
+ *
+ * Copyright (C) 2016 BayLibre SAS
+ *
+ * Author:
+ *   Bartosz Golaszewski <bgolaszewski-rdvid1DuHRBpdZSXdFL2CA@public.gmane.org>
+ *
+ * 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/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+
+#define DA8XX_IO_PHYS			0x01c00000ul
+#define DA8XX_SYSCFG0_BASE		(DA8XX_IO_PHYS + 0x14000)
+
+#define DA8XX_MSTPRI0_REG		0x110
+#define DA8XX_MSTPRI1_REG		0x114
+#define DA8XX_MSTPRI2_REG		0x118
+
+#define DA8XX_MSTPRI_MAX		7
+
+struct da8xx_mstpri_descr {
+	const char *property;
+	int reg;
+	int shift;
+	int mask;
+};
+
+static const struct da8xx_mstpri_descr priorities[] = {
+	{
+		.property = "ti,pri-arm-i",
+		.reg = DA8XX_MSTPRI0_REG,
+		.shift = 0,
+		.mask = 0xfffffff0,
+	},
+	{
+		.property = "ti,pri-arm-d",
+		.reg = DA8XX_MSTPRI0_REG,
+		.shift = 4,
+		.mask = 0xffffff0f,
+	},
+	{
+		.property = "ti,pri-upp",
+		.reg = DA8XX_MSTPRI0_REG,
+		.shift = 16,
+		.mask = 0xfff0ffff,
+	},
+	{
+		.property = "ti,pri-sata",
+		.reg = DA8XX_MSTPRI0_REG,
+		.shift = 20,
+		.mask = 0xff0fffff,
+	},
+	{
+		.property = "ti,pri-pru0",
+		.reg = DA8XX_MSTPRI1_REG,
+		.shift = 0,
+		.mask = 0xfffffff0,
+	},
+	{
+		.property = "ti,pri-pru1",
+		.reg = DA8XX_MSTPRI1_REG,
+		.shift = 4,
+		.mask = 0xffffff0f,
+	},
+	{
+		.property = "ti,pri-edma30tc0",
+		.reg = DA8XX_MSTPRI1_REG,
+		.shift = 8,
+		.mask = 0xfffff0ff,
+	},
+	{
+		.property = "ti,pri-edma30tc1",
+		.reg = DA8XX_MSTPRI1_REG,
+		.shift = 12,
+		.mask = 0xffff0fff,
+	},
+	{
+		.property = "ti,pri-edma31tc0",
+		.reg = DA8XX_MSTPRI1_REG,
+		.shift = 16,
+		.mask = 0xfff0ffff,
+	},
+	{
+		.property = "ti,pri-vpif-dma-0",
+		.reg = DA8XX_MSTPRI1_REG,
+		.shift = 24,
+		.mask = 0xf0ffffff,
+	},
+	{
+		.property = "ti,pri-vpif-dma-1",
+		.reg = DA8XX_MSTPRI1_REG,
+		.shift = 28,
+		.mask = 0x0fffffff,
+	},
+	{
+		.property = "ti,pri-emac",
+		.reg = DA8XX_MSTPRI2_REG,
+		.shift = 0,
+		.mask = 0xfffffff0,
+	},
+	{
+		.property = "ti,pri-usb0cfg",
+		.reg = DA8XX_MSTPRI2_REG,
+		.shift = 8,
+		.mask = 0xfffff0ff,
+	},
+	{
+		.property = "ti,pri-usb0cdma",
+		.reg = DA8XX_MSTPRI2_REG,
+		.shift = 12,
+		.mask = 0xffff0fff,
+	},
+	{
+		.property = "ti,pri-uhpi",
+		.reg = DA8XX_MSTPRI2_REG,
+		.shift = 20,
+		.mask = 0xff0fffff,
+	},
+	{
+		.property = "ti,pri-usb1",
+		.reg = DA8XX_MSTPRI2_REG,
+		.shift = 24,
+		.mask = 0xf0ffffff,
+	},
+	{
+		.property = "ti,pri-lcdc",
+		.reg = DA8XX_MSTPRI2_REG,
+		.shift = 28,
+		.mask = 0x0fffffff,
+	},
+};
+
+static void da8xx_syscfg_set_mstpri(void __iomem *syscfg0, struct device *dev)
+{
+	const struct da8xx_mstpri_descr *pri_descr;
+	struct device_node *node = dev->of_node;
+	void __iomem *mstpri;
+	u32 old_pri, new_pri;
+	int ret, i;
+
+	for (i = 0; i < ARRAY_SIZE(priorities); i++) {
+		pri_descr = &priorities[i];
+
+		ret = of_property_read_u32(node, pri_descr->property, &new_pri);
+		if (ret)
+			continue;
+
+		if (new_pri > DA8XX_MSTPRI_MAX) {
+			dev_warn(dev,
+				 "omitting property '%s' - value too high\n",
+				 pri_descr->property);
+			continue;
+		}
+
+		mstpri = syscfg0 + pri_descr->reg;
+		old_pri = __raw_readl(mstpri);
+		old_pri &= pri_descr->mask;
+		new_pri <<= pri_descr->shift;
+		new_pri |= old_pri;
+
+		__raw_writel(new_pri, mstpri);
+	}
+}
+
+static int da8xx_syscfg_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	void __iomem *syscfg0;
+
+	syscfg0 = ioremap(DA8XX_SYSCFG0_BASE, SZ_4K);
+	if (!syscfg0) {
+		dev_err(dev, "unable to map syscfg0\n");
+		return -EIO;
+	}
+
+	da8xx_syscfg_set_mstpri(syscfg0, dev);
+
+	iounmap(syscfg0);
+
+	return 0;
+}
+
+static const struct of_device_id da8xx_syscfg_of_match[] = {
+	{ .compatible = "ti,da850-syscfg", },
+	{ },
+};
+
+static struct platform_driver da8xx_syscfg_driver = {
+	.probe = da8xx_syscfg_probe,
+	.driver = {
+		.name = "da8xx-syscfg",
+		.of_match_table = da8xx_syscfg_of_match,
+	},
+};
+module_platform_driver(da8xx_syscfg_driver);
+
+MODULE_AUTHOR("Bartosz Golaszewski <bgolaszewski-rdvid1DuHRBWk0Htik3J/w@public.gmane.org>");
+MODULE_DESCRIPTION("TI da8xx System Configuration driver");
+MODULE_LICENSE("GPL v2");
-- 
2.9.3

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