bus: Add support for Tegra Generic Memory Interface (40eb4776) · Commits · 戴 / test

drivers/bus/Kconfig

+7 −0

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		@@ -149,6 +149,13 @@ config TEGRA_ACONNECT
		Driver for the Tegra ACONNECT bus which is used to interface with
		the devices inside the Audio Processing Engine (APE) for Tegra210.

		config TEGRA_GMI
		tristate "Tegra Generic Memory Interface bus driver"
		depends on ARCH_TEGRA
		help
		Driver for the Tegra Generic Memory Interface bus which can be used
		to attach devices such as NOR, UART, FPGA and more.

		config UNIPHIER_SYSTEM_BUS
		tristate "UniPhier System Bus driver"
		depends on ARCH_UNIPHIER && OF

drivers/bus/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -19,5 +19,6 @@ obj-$(CONFIG_QCOM_EBI2) += qcom-ebi2.o
		obj-$(CONFIG_SUNXI_RSB) += sunxi-rsb.o
		obj-$(CONFIG_SIMPLE_PM_BUS) += simple-pm-bus.o
		obj-$(CONFIG_TEGRA_ACONNECT) += tegra-aconnect.o
		obj-$(CONFIG_TEGRA_GMI) += tegra-gmi.o
		obj-$(CONFIG_UNIPHIER_SYSTEM_BUS) += uniphier-system-bus.o
		obj-$(CONFIG_VEXPRESS_CONFIG) += vexpress-config.o

drivers/bus/tegra-gmi.c

0 → 100644

+284 −0

Original line number	Diff line number	Diff line
		/*
		* Driver for NVIDIA Generic Memory Interface
		*
		* Copyright (C) 2016 Host Mobility AB. All rights reserved.
		*
		* This file is licensed under the terms of the GNU General Public
		* License version 2. This program is licensed "as is" without any
		* warranty of any kind, whether express or implied.
		*/

		#include <linux/clk.h>
		#include <linux/delay.h>
		#include <linux/io.h>
		#include <linux/module.h>
		#include <linux/of_device.h>
		#include <linux/reset.h>

		#define TEGRA_GMI_CONFIG 0x00
		#define TEGRA_GMI_CONFIG_GO BIT(31)
		#define TEGRA_GMI_BUS_WIDTH_32BIT BIT(30)
		#define TEGRA_GMI_MUX_MODE BIT(28)
		#define TEGRA_GMI_RDY_BEFORE_DATA BIT(24)
		#define TEGRA_GMI_RDY_ACTIVE_HIGH BIT(23)
		#define TEGRA_GMI_ADV_ACTIVE_HIGH BIT(22)
		#define TEGRA_GMI_OE_ACTIVE_HIGH BIT(21)
		#define TEGRA_GMI_CS_ACTIVE_HIGH BIT(20)
		#define TEGRA_GMI_CS_SELECT(x) ((x & 0x7) << 4)

		#define TEGRA_GMI_TIMING0 0x10
		#define TEGRA_GMI_MUXED_WIDTH(x) ((x & 0xf) << 12)
		#define TEGRA_GMI_HOLD_WIDTH(x) ((x & 0xf) << 8)
		#define TEGRA_GMI_ADV_WIDTH(x) ((x & 0xf) << 4)
		#define TEGRA_GMI_CE_WIDTH(x) (x & 0xf)

		#define TEGRA_GMI_TIMING1 0x14
		#define TEGRA_GMI_WE_WIDTH(x) ((x & 0xff) << 16)
		#define TEGRA_GMI_OE_WIDTH(x) ((x & 0xff) << 8)
		#define TEGRA_GMI_WAIT_WIDTH(x) (x & 0xff)

		#define TEGRA_GMI_MAX_CHIP_SELECT 8

		struct tegra_gmi {
		struct device *dev;
		void __iomem *base;
		struct clk *clk;
		struct reset_control *rst;

		u32 snor_config;
		u32 snor_timing0;
		u32 snor_timing1;
		};

		static int tegra_gmi_enable(struct tegra_gmi *gmi)
		{
		int err;

		err = clk_prepare_enable(gmi->clk);
		if (err < 0) {
		dev_err(gmi->dev, "failed to enable clock: %d\n", err);
		return err;
		}

		reset_control_assert(gmi->rst);
		usleep_range(2000, 4000);
		reset_control_deassert(gmi->rst);

		writel(gmi->snor_timing0, gmi->base + TEGRA_GMI_TIMING0);
		writel(gmi->snor_timing1, gmi->base + TEGRA_GMI_TIMING1);

		gmi->snor_config \|= TEGRA_GMI_CONFIG_GO;
		writel(gmi->snor_config, gmi->base + TEGRA_GMI_CONFIG);

		return 0;
		}

		static void tegra_gmi_disable(struct tegra_gmi *gmi)
		{
		u32 config;

		/* stop GMI operation */
		config = readl(gmi->base + TEGRA_GMI_CONFIG);
		config &= ~TEGRA_GMI_CONFIG_GO;
		writel(config, gmi->base + TEGRA_GMI_CONFIG);

		reset_control_assert(gmi->rst);
		clk_disable_unprepare(gmi->clk);
		}

		static int tegra_gmi_parse_dt(struct tegra_gmi *gmi)
		{
		struct device_node *child;
		u32 property, ranges[4];
		int err;

		child = of_get_next_available_child(gmi->dev->of_node, NULL);
		if (!child) {
		dev_err(gmi->dev, "no child nodes found\n");
		return -ENODEV;
		}

		/*
		* We currently only support one child device due to lack of
		* chip-select address decoding. Which means that we only have one
		* chip-select line from the GMI controller.
		*/
		if (of_get_child_count(gmi->dev->of_node) > 1)
		dev_warn(gmi->dev, "only one child device is supported.");

		if (of_property_read_bool(child, "nvidia,snor-data-width-32bit"))
		gmi->snor_config \|= TEGRA_GMI_BUS_WIDTH_32BIT;

		if (of_property_read_bool(child, "nvidia,snor-mux-mode"))
		gmi->snor_config \|= TEGRA_GMI_MUX_MODE;

		if (of_property_read_bool(child, "nvidia,snor-rdy-active-before-data"))
		gmi->snor_config \|= TEGRA_GMI_RDY_BEFORE_DATA;

		if (of_property_read_bool(child, "nvidia,snor-rdy-active-high"))
		gmi->snor_config \|= TEGRA_GMI_RDY_ACTIVE_HIGH;

		if (of_property_read_bool(child, "nvidia,snor-adv-active-high"))
		gmi->snor_config \|= TEGRA_GMI_ADV_ACTIVE_HIGH;

		if (of_property_read_bool(child, "nvidia,snor-oe-active-high"))
		gmi->snor_config \|= TEGRA_GMI_OE_ACTIVE_HIGH;

		if (of_property_read_bool(child, "nvidia,snor-cs-active-high"))
		gmi->snor_config \|= TEGRA_GMI_CS_ACTIVE_HIGH;

		/* Decode the CS# */
		err = of_property_read_u32_array(child, "ranges", ranges, 4);
		if (err < 0) {
		/* Invalid binding */
		if (err == -EOVERFLOW) {
		dev_err(gmi->dev,
		"failed to decode CS: invalid ranges length\n");
		goto error_cs;
		}

		/*
		* If we reach here it means that the child node has an empty
		* ranges or it does not exist at all. Attempt to decode the
		* CS# from the reg property instead.
		*/
		err = of_property_read_u32(child, "reg", &property);
		if (err < 0) {
		dev_err(gmi->dev,
		"failed to decode CS: no reg property found\n");
		goto error_cs;
		}
		} else {
		property = ranges[1];
		}

		/* Valid chip selects are CS0-CS7 */
		if (property >= TEGRA_GMI_MAX_CHIP_SELECT) {
		dev_err(gmi->dev, "invalid chip select: %d", property);
		err = -EINVAL;
		goto error_cs;
		}

		gmi->snor_config \|= TEGRA_GMI_CS_SELECT(property);

		/* The default values that are provided below are reset values */
		if (!of_property_read_u32(child, "nvidia,snor-muxed-width", &property))
		gmi->snor_timing0 \|= TEGRA_GMI_MUXED_WIDTH(property);
		else
		gmi->snor_timing0 \|= TEGRA_GMI_MUXED_WIDTH(1);

		if (!of_property_read_u32(child, "nvidia,snor-hold-width", &property))
		gmi->snor_timing0 \|= TEGRA_GMI_HOLD_WIDTH(property);
		else
		gmi->snor_timing0 \|= TEGRA_GMI_HOLD_WIDTH(1);

		if (!of_property_read_u32(child, "nvidia,snor-adv-width", &property))
		gmi->snor_timing0 \|= TEGRA_GMI_ADV_WIDTH(property);
		else
		gmi->snor_timing0 \|= TEGRA_GMI_ADV_WIDTH(1);

		if (!of_property_read_u32(child, "nvidia,snor-ce-width", &property))
		gmi->snor_timing0 \|= TEGRA_GMI_CE_WIDTH(property);
		else
		gmi->snor_timing0 \|= TEGRA_GMI_CE_WIDTH(4);

		if (!of_property_read_u32(child, "nvidia,snor-we-width", &property))
		gmi->snor_timing1 \|= TEGRA_GMI_WE_WIDTH(property);
		else
		gmi->snor_timing1 \|= TEGRA_GMI_WE_WIDTH(1);

		if (!of_property_read_u32(child, "nvidia,snor-oe-width", &property))
		gmi->snor_timing1 \|= TEGRA_GMI_OE_WIDTH(property);
		else
		gmi->snor_timing1 \|= TEGRA_GMI_OE_WIDTH(1);

		if (!of_property_read_u32(child, "nvidia,snor-wait-width", &property))
		gmi->snor_timing1 \|= TEGRA_GMI_WAIT_WIDTH(property);
		else
		gmi->snor_timing1 \|= TEGRA_GMI_WAIT_WIDTH(3);

		error_cs:
		of_node_put(child);
		return err;
		}

		static int tegra_gmi_probe(struct platform_device *pdev)
		{
		struct device *dev = &pdev->dev;
		struct tegra_gmi *gmi;
		struct resource *res;
		int err;

		gmi = devm_kzalloc(dev, sizeof(*gmi), GFP_KERNEL);
		if (!gmi)
		return -ENOMEM;

		gmi->dev = dev;

		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
		gmi->base = devm_ioremap_resource(dev, res);
		if (IS_ERR(gmi->base))
		return PTR_ERR(gmi->base);

		gmi->clk = devm_clk_get(dev, "gmi");
		if (IS_ERR(gmi->clk)) {
		dev_err(dev, "can not get clock\n");
		return PTR_ERR(gmi->clk);
		}

		gmi->rst = devm_reset_control_get(dev, "gmi");
		if (IS_ERR(gmi->rst)) {
		dev_err(dev, "can not get reset\n");
		return PTR_ERR(gmi->rst);
		}

		err = tegra_gmi_parse_dt(gmi);
		if (err)
		return err;

		err = tegra_gmi_enable(gmi);
		if (err < 0)
		return err;

		err = of_platform_default_populate(dev->of_node, NULL, dev);
		if (err < 0) {
		dev_err(dev, "fail to create devices.\n");
		tegra_gmi_disable(gmi);
		return err;
		}

		platform_set_drvdata(pdev, gmi);

		return 0;
		}

		static int tegra_gmi_remove(struct platform_device *pdev)
		{
		struct tegra_gmi *gmi = platform_get_drvdata(pdev);

		of_platform_depopulate(gmi->dev);
		tegra_gmi_disable(gmi);

		return 0;
		}

		static const struct of_device_id tegra_gmi_id_table[] = {
		{ .compatible = "nvidia,tegra20-gmi", },
		{ .compatible = "nvidia,tegra30-gmi", },
		{ }
		};
		MODULE_DEVICE_TABLE(of, tegra_gmi_id_table);

		static struct platform_driver tegra_gmi_driver = {
		.probe = tegra_gmi_probe,
		.remove = tegra_gmi_remove,
		.driver = {
		.name = "tegra-gmi",
		.of_match_table = tegra_gmi_id_table,
		},
		};
		module_platform_driver(tegra_gmi_driver);

		MODULE_AUTHOR("Mirza Krak <mirza.krak@gmail.com");
		MODULE_DESCRIPTION("NVIDIA Tegra GMI Bus Driver");
		MODULE_LICENSE("GPL v2");

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