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-rw-r--r--Documentation/devicetree/bindings/bus/nvidia,tegra20-gmi.txt132
-rw-r--r--drivers/bus/Kconfig7
-rw-r--r--drivers/bus/Makefile1
-rw-r--r--drivers/bus/tegra-gmi.c284
4 files changed, 424 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/bus/nvidia,tegra20-gmi.txt b/Documentation/devicetree/bindings/bus/nvidia,tegra20-gmi.txt
new file mode 100644
index 0000000..83b0e54
--- /dev/null
+++ b/Documentation/devicetree/bindings/bus/nvidia,tegra20-gmi.txt
@@ -0,0 +1,132 @@
+Device tree bindings for NVIDIA Tegra Generic Memory Interface bus
+
+The Generic Memory Interface bus enables memory transfers between internal and
+external memory. Can be used to attach various high speed devices such as
+synchronous/asynchronous NOR, FPGA, UARTS and more.
+
+The actual devices are instantiated from the child nodes of a GMI node.
+
+Required properties:
+ - compatible : Should contain one of the following:
+ For Tegra20 must contain "nvidia,tegra20-gmi".
+ For Tegra30 must contain "nvidia,tegra30-gmi".
+ - reg: Should contain GMI controller registers location and length.
+ - clocks: Must contain an entry for each entry in clock-names.
+ - clock-names: Must include the following entries: "gmi"
+ - resets : Must contain an entry for each entry in reset-names.
+ - reset-names : Must include the following entries: "gmi"
+ - #address-cells: The number of cells used to represent physical base
+ addresses in the GMI address space. Should be 2.
+ - #size-cells: The number of cells used to represent the size of an address
+ range in the GMI address space. Should be 1.
+ - ranges: Must be set up to reflect the memory layout with three integer values
+ for each chip-select line in use (only one entry is supported, see below
+ comments):
+ <cs-number> <offset> <physical address of mapping> <size>
+
+Note that the GMI controller does not have any internal chip-select address
+decoding, because of that chip-selects either need to be managed via software
+or by employing external chip-select decoding logic.
+
+If external chip-select logic is used to support multiple devices it is assumed
+that the devices use the same timing and so are probably the same type. It also
+assumes that they can fit in the 256MB address range. In this case only one
+child device is supported which represents the active chip-select line, see
+examples for more insight.
+
+The chip-select number is decoded from the child nodes second address cell of
+'ranges' property, if 'ranges' property is not present or empty chip-select will
+then be decoded from the first cell of the 'reg' property.
+
+Optional child cs node properties:
+
+ - nvidia,snor-data-width-32bit: Use 32bit data-bus, default is 16bit.
+ - nvidia,snor-mux-mode: Enable address/data MUX mode.
+ - nvidia,snor-rdy-active-before-data: Assert RDY signal one cycle before data.
+ If omitted it will be asserted with data.
+ - nvidia,snor-rdy-active-high: RDY signal is active high
+ - nvidia,snor-adv-active-high: ADV signal is active high
+ - nvidia,snor-oe-active-high: WE/OE signal is active high
+ - nvidia,snor-cs-active-high: CS signal is active high
+
+ Note that there is some special handling for the timing values.
+ From Tegra TRM:
+ Programming 0 means 1 clock cycle: actual cycle = programmed cycle + 1
+
+ - nvidia,snor-muxed-width: Number of cycles MUX address/data asserted on the
+ bus. Valid values are 0-15, default is 1
+ - nvidia,snor-hold-width: Number of cycles CE stays asserted after the
+ de-assertion of WR_N (in case of SLAVE/MASTER Request) or OE_N
+ (in case of MASTER Request). Valid values are 0-15, default is 1
+ - nvidia,snor-adv-width: Number of cycles during which ADV stays asserted.
+ Valid values are 0-15, default is 1.
+ - nvidia,snor-ce-width: Number of cycles before CE is asserted.
+ Valid values are 0-15, default is 4
+ - nvidia,snor-we-width: Number of cycles during which WE stays asserted.
+ Valid values are 0-15, default is 1
+ - nvidia,snor-oe-width: Number of cycles during which OE stays asserted.
+ Valid values are 0-255, default is 1
+ - nvidia,snor-wait-width: Number of cycles before READY is asserted.
+ Valid values are 0-255, default is 3
+
+Example with two SJA1000 CAN controllers connected to the GMI bus. We wrap the
+controllers with a simple-bus node since they are all connected to the same
+chip-select (CS4), in this example external address decoding is provided:
+
+gmi@70090000 {
+ compatible = "nvidia,tegra20-gmi";
+ reg = <0x70009000 0x1000>;
+ #address-cells = <2>;
+ #size-cells = <1>;
+ clocks = <&tegra_car TEGRA20_CLK_NOR>;
+ clock-names = "gmi";
+ resets = <&tegra_car 42>;
+ reset-names = "gmi";
+ ranges = <4 0 0xd0000000 0xfffffff>;
+
+ status = "okay";
+
+ bus@4,0 {
+ compatible = "simple-bus";
+ #address-cells = <1>;
+ #size-cells = <1>;
+ ranges = <0 4 0 0x40100>;
+
+ nvidia,snor-mux-mode;
+ nvidia,snor-adv-active-high;
+
+ can@0 {
+ reg = <0 0x100>;
+ ...
+ };
+
+ can@40000 {
+ reg = <0x40000 0x100>;
+ ...
+ };
+ };
+};
+
+Example with one SJA1000 CAN controller connected to the GMI bus
+on CS4:
+
+gmi@70090000 {
+ compatible = "nvidia,tegra20-gmi";
+ reg = <0x70009000 0x1000>;
+ #address-cells = <2>;
+ #size-cells = <1>;
+ clocks = <&tegra_car TEGRA20_CLK_NOR>;
+ clock-names = "gmi";
+ resets = <&tegra_car 42>;
+ reset-names = "gmi";
+ ranges = <4 0 0xd0000000 0xfffffff>;
+
+ status = "okay";
+
+ can@4,0 {
+ reg = <4 0 0x100>;
+ nvidia,snor-mux-mode;
+ nvidia,snor-adv-active-high;
+ ...
+ };
+};
diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
index ed6a89c..647d95d 100644
--- a/drivers/bus/Kconfig
+++ b/drivers/bus/Kconfig
@@ -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
diff --git a/drivers/bus/Makefile b/drivers/bus/Makefile
index 2adb540..cc6364b 100644
--- a/drivers/bus/Makefile
+++ b/drivers/bus/Makefile
@@ -19,6 +19,7 @@ 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
diff --git a/drivers/bus/tegra-gmi.c b/drivers/bus/tegra-gmi.c
new file mode 100644
index 0000000..a657078
--- /dev/null
+++ b/drivers/bus/tegra-gmi.c
@@ -0,0 +1,284 @@
+/*
+ * 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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