openwrt/target/linux/brcm2708/patches-3.18/0053-i2c-bcm2708-add-device-tree-support.patch

From 772f3f8c0c321b2817d35f48d553db023ead2d90 Mon Sep 17 00:00:00 2001
From: notro <notro@tronnes.org>
Date: Tue, 29 Jul 2014 11:04:49 +0200
Subject: [PATCH 053/114] i2c: bcm2708: add device tree support

Add DT support to driver and add to .dtsi file.
Setup pins in .dts file.
i2c is disabled by default.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

bcm2708: don't register i2c controllers when using DT

The devices for the i2c controllers are in the Device Tree.
Only register devices when not using DT.

Signed-off-by: Noralf Tronnes <notro@tronnes.org>

i2c: bcm2835: make driver available on ARCH_BCM2708

Make this driver available on ARCH_BCM2708

Signed-off-by: Noralf Tronnes <notro@tronnes.org>
---
 arch/arm/boot/dts/bcm2708-rpi-b.dts | 24 ++++++++++++++++++++++++
 arch/arm/boot/dts/bcm2708.dtsi      | 27 +++++++++++++++++++++++++++
 arch/arm/mach-bcm2708/bcm2708.c     |  6 ++++--
 drivers/i2c/busses/Kconfig          |  2 +-
 drivers/i2c/busses/i2c-bcm2708.c    | 24 ++++++++++++++++++++++++
 5 files changed, 80 insertions(+), 3 deletions(-)

--- a/arch/arm/boot/dts/bcm2708-rpi-b.dts
+++ b/arch/arm/boot/dts/bcm2708-rpi-b.dts
@@ -8,6 +8,8 @@
 
 	aliases {
 		spi0 = &spi0;
+		i2c0 = &i2c0;
+		i2c1 = &i2c1;
 	};
 };
 
@@ -16,6 +18,16 @@
 		brcm,pins = <7 8 9 10 11>;
 		brcm,function = <4>; /* alt0 */
 	};
+
+	i2c0_pins: i2c0 {
+		brcm,pins = <0 1>;
+		brcm,function = <4>;
+	};
+
+	i2c1_pins: i2c1 {
+		brcm,pins = <2 3>;
+		brcm,function = <4>;
+	};
 };
 
 &spi0 {
@@ -38,3 +50,15 @@
 		spi-max-frequency = <500000>;
 	};
 };
+
+&i2c0 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&i2c0_pins>;
+	clock-frequency = <100000>;
+};
+
+&i2c1 {
+	pinctrl-names = "default";
+	pinctrl-0 = <&i2c1_pins>;
+	clock-frequency = <100000>;
+};
--- a/arch/arm/boot/dts/bcm2708.dtsi
+++ b/arch/arm/boot/dts/bcm2708.dtsi
@@ -48,6 +48,26 @@
 			#size-cells = <0>;
 			status = "disabled";
 		};
+
+		i2c0: i2c@7e205000 {
+			compatible = "brcm,bcm2708-i2c";
+			reg = <0x7e205000 0x1000>;
+			interrupts = <2 21>;
+			clocks = <&clk_i2c>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+			status = "disabled";
+		};
+
+		i2c1: i2c@7e804000 {
+			compatible = "brcm,bcm2708-i2c";
+			reg = <0x7e804000 0x1000>;
+			interrupts = <2 21>;
+			clocks = <&clk_i2c>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+			status = "disabled";
+		};
 	};
 
 	clocks {
@@ -55,6 +75,13 @@
 		#address-cells = <1>;
 		#size-cells = <0>;
 
+		clk_i2c: i2c {
+			compatible = "fixed-clock";
+			reg = <1>;
+			#clock-cells = <0>;
+			clock-frequency = <250000000>;
+		};
+
 		clk_spi: clock@2 {
 			compatible = "fixed-clock";
 			reg = <2>;
--- a/arch/arm/mach-bcm2708/bcm2708.c
+++ b/arch/arm/mach-bcm2708/bcm2708.c
@@ -532,6 +532,7 @@ static struct spi_board_info bcm2708_spi
 };
 #endif
 
+#ifndef CONFIG_OF
 static struct resource bcm2708_bsc0_resources[] = {
 	{
 		.start = BSC0_BASE,
@@ -570,6 +571,7 @@ static struct platform_device bcm2708_bs
 	.num_resources = ARRAY_SIZE(bcm2708_bsc1_resources),
 	.resource = bcm2708_bsc1_resources,
 };
+#endif
 
 static struct platform_device bcm2835_hwmon_device = {
 	.name = "bcm2835_hwmon",
@@ -797,8 +799,8 @@ void __init bcm2708_init(void)
 		bcm_register_device(&bcm2708_alsa_devices[i]);
 
 	bcm_register_device_dt(&bcm2708_spi_device);
-	bcm_register_device(&bcm2708_bsc0_device);
-	bcm_register_device(&bcm2708_bsc1_device);
+	bcm_register_device_dt(&bcm2708_bsc0_device);
+	bcm_register_device_dt(&bcm2708_bsc1_device);
 
 	bcm_register_device(&bcm2835_hwmon_device);
 	bcm_register_device(&bcm2835_thermal_device);
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -361,7 +361,7 @@ config I2C_AXXIA
 
 config I2C_BCM2835
 	tristate "Broadcom BCM2835 I2C controller"
-	depends on ARCH_BCM2835
+	depends on ARCH_BCM2835 || ARCH_BCM2708
 	help
 	  If you say yes to this option, support will be included for the
 	  BCM2835 I2C controller.
--- a/drivers/i2c/busses/i2c-bcm2708.c
+++ b/drivers/i2c/busses/i2c-bcm2708.c
@@ -26,6 +26,7 @@
 #include <linux/spinlock.h>
 #include <linux/clk.h>
 #include <linux/err.h>
+#include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/io.h>
 #include <linux/slab.h>
@@ -303,6 +304,21 @@ static int bcm2708_i2c_probe(struct plat
 	unsigned long bus_hz;
 	u32 cdiv;
 
+	if (pdev->dev.of_node) {
+		u32 bus_clk_rate;
+		pdev->id = of_alias_get_id(pdev->dev.of_node, "i2c");
+		if (pdev->id < 0) {
+			dev_err(&pdev->dev, "alias is missing\n");
+			return -EINVAL;
+		}
+		if (!of_property_read_u32(pdev->dev.of_node,
+					"clock-frequency", &bus_clk_rate))
+			baudrate = bus_clk_rate;
+		else
+			dev_warn(&pdev->dev,
+				"Could not read clock-frequency property\n");
+	}
+
 	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!regs) {
 		dev_err(&pdev->dev, "could not get IO memory\n");
@@ -336,6 +352,7 @@ static int bcm2708_i2c_probe(struct plat
 	adap->dev.parent = &pdev->dev;
 	adap->nr = pdev->id;
 	strlcpy(adap->name, dev_name(&pdev->dev), sizeof(adap->name));
+	adap->dev.of_node = pdev->dev.of_node;
 
 	switch (pdev->id) {
 	case 0:
@@ -416,10 +433,17 @@ static int bcm2708_i2c_remove(struct pla
 	return 0;
 }
 
+static const struct of_device_id bcm2708_i2c_of_match[] = {
+        { .compatible = "brcm,bcm2708-i2c" },
+        {},
+};
+MODULE_DEVICE_TABLE(of, bcm2708_i2c_of_match);
+
 static struct platform_driver bcm2708_i2c_driver = {
 	.driver		= {
 		.name	= DRV_NAME,
 		.owner	= THIS_MODULE,
+		.of_match_table = bcm2708_i2c_of_match,
 	},
 	.probe		= bcm2708_i2c_probe,
 	.remove		= bcm2708_i2c_remove,