[PATCH 1/1] Drivers: USB: DA8xx MUSB: added DT support

[Petr Kulhavy <petr-Qh/3xLP0EvwAvxtiuMwx3w@public.gmane.org>]

TI DA8xx MUSB driver equipped with DeviceTree support.
Tested with AM1808 board and USB2.0 (OTG) in host mode.

Signed-off-by: Petr Kulhavy <petr-Qh/3xLP0EvwAvxtiuMwx3w@public.gmane.org>
---
 .../devicetree/bindings/usb/da8xx-usb.txt          |  63 ++++++++
 drivers/usb/musb/da8xx.c                           | 162 +++++++++++++++++++++
 include/linux/platform_data/usb-davinci.h          |   3 +-
 3 files changed, 227 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/usb/da8xx-usb.txt

diff --git a/Documentation/devicetree/bindings/usb/da8xx-usb.txt b/Documentation/devicetree/bindings/usb/da8xx-usb.txt
new file mode 100644
index 0000000..69c0961
--- /dev/null
+++ b/Documentation/devicetree/bindings/usb/da8xx-usb.txt
@@ -0,0 +1,63 @@
+TI DA8xx MUSB
+~~~~~~~~~~~~~
+
+Required properties:
+~~~~~~~~~~~~~~~~~~~~
+ - compatible : Should be "ti,da8xx-musb"
+
+ - reg: offset and length of the usbss register sets
+
+ - interrupts: USB interrupt number
+
+ - interrupt-names: should be set to "mc"
+
+ - dr_mode: The USB operation mode. Should be one of "host", "peripheral" or "otg".
+
+ - mentor,power : Specifies the maximum current in milli-ampers the controller can
+     supply in host mode. The maximum configurable value is 510mA.
+
+ - mentor,num-eps : Valid only in host mode. Specifies the number of target endpoints
+     supported by the controller. For DA8xx it is "5".
+
+ - mentor,multipoint : Valid only in host mode. Enables addressing of USB hubs,
+     which is normally something you want and therefore should be set to "1".
+     If set to "0" only point-to-point communication is enabled, i.e. only a single
+     device can be attached.
+
+ - mentor,ram-bits : This 2-base logarithm value defines the RAM FIFO size of the controller.
+     The FIFO size is calculated in 32-bit words. E.g. if your controller has 4kiB of RAM FIFO
+     this value should be set to "10": 2^10 = 1024 words of 32-bits, i.e. 4096 bytes.
+     For the DA8xx controller this value should be set to 10.
+
+
+Optional properties:
+
+ - ti,phy20-clkmux-cfg: Integer. Defines the USB 2.0 PHY reference clock source.
+     Supported values: "0" for external pin, "1" for internal PLL.
+
+ - ti,phy20-refclock-frequency : Integer. Defines the USB 2.0 PHY reference clock input
+     frequency in Hz in case the clock is generated by the internal PLL.
+     Supported values are 12MHz, 13MHz, 19.2MHz, 20MHz, 24MHz, 26MHz, 38.4MHz, 40MHz, 48MHz
+
+
+Example:
+
+	usb20: usb@1e00000 {
+		compatible = "ti,da8xx-musb";
+		ti,hwmods = "usb_otg_hs";
+		reg =   <0x00200000 0x10000>;
+		interrupt-parent = <&intc>;
+		interrupts = <58>;
+		interrupt-names = "mc";
+
+		dr_mode = "host";
+		mentor,power = <500>;
+		mentor,multipoint = <1>;
+		mentor,num-eps = <5>;
+		mentor,ram-bits = <10>;
+
+		ti,phy20-clkmux-cfg = <1>;	/* PHY clock internally generated from the PLL */
+		ti,phy20-refclock-frequency = <24000000>;
+
+		status = "okay";
+	};
diff --git a/drivers/usb/musb/da8xx.c b/drivers/usb/musb/da8xx.c
index 4e13fe2..281d503 100644
--- a/drivers/usb/musb/da8xx.c
+++ b/drivers/usb/musb/da8xx.c
@@ -1,6 +1,9 @@
 /*
  * Texas Instruments DA8xx/OMAP-L1x "glue layer"
  *
+ * DT support
+ * Copyright (c) 2015-2016 Petr Kulhavy, Barix AG <petr-Qh/3xLP0EvwAvxtiuMwx3w@public.gmane.org>
+ *
  * Copyright (c) 2008-2009 MontaVista Software, Inc. <source-Igf4POYTYCDQT0dZR+AlfA@public.gmane.org>
  *
  * Based on the DaVinci "glue layer" code.
@@ -36,6 +39,8 @@
 
 #include <mach/da8xx.h>
 #include <linux/platform_data/usb-davinci.h>
+#include <linux/of_platform.h>
+#include <linux/usb/of.h>
 
 #include "musb_core.h"
 
@@ -134,6 +139,35 @@ static inline void phy_off(void)
 	__raw_writel(cfgchip2, CFGCHIP2);
 }
 
+/* converts PHY refclk frequency in HZ into USB0REF_FREQ config value
+ * on unsupported frequency returns -1
+ */
+static inline int phy_refclk_cfg(int frequency)
+{
+	switch (frequency) {
+	case 12000000:
+		return 0x01;
+	case 13000000:
+		return 0x06;
+	case 19200000:
+		return 0x05;
+	case 20000000:
+		return 0x08;
+	case 24000000:
+		return 0x02;
+	case 26000000:
+		return 0x07;
+	case 38400000:
+		return 0x05;
+	case 40000000:
+		return 0x09;
+	case 48000000:
+		return 0x03;
+	default:
+		return -1;
+	}
+}
+
 /*
  * Because we don't set CTRL.UINT, it's "important" to:
  *	- not read/write INTRUSB/INTRUSBE (except during
@@ -527,6 +561,35 @@ static const struct platform_device_info da8xx_dev_info = {
 	.dma_mask	= DMA_BIT_MASK(32),
 };
 
+static int get_musb_port_mode(struct device_node *np)
+{
+	enum usb_dr_mode mode;
+
+	mode = of_usb_get_dr_mode(np);
+	switch (mode) {
+	case USB_DR_MODE_HOST:
+		return MUSB_HOST;
+
+	case USB_DR_MODE_PERIPHERAL:
+		return MUSB_PERIPHERAL;
+
+	case USB_DR_MODE_OTG:
+		return MUSB_OTG;
+
+	default:
+		return MUSB_UNDEFINED;
+	}
+}
+
+static int get_int_prop(struct device_node *dn, const char *s)
+{
+	int ret;
+	u32 val;
+
+	ret = of_property_read_u32(dn, s, &val);
+	return ret ? 0 : val;
+}
+
 static int da8xx_probe(struct platform_device *pdev)
 {
 	struct resource musb_resources[2];
@@ -535,6 +598,7 @@ static int da8xx_probe(struct platform_device *pdev)
 	struct da8xx_glue		*glue;
 	struct platform_device_info	pinfo;
 	struct clk			*clk;
+	struct device_node		*np = pdev->dev.of_node;
 
 	int				ret = -ENOMEM;
 
@@ -560,6 +624,95 @@ static int da8xx_probe(struct platform_device *pdev)
 	glue->dev			= &pdev->dev;
 	glue->clk			= clk;
 
+	if (IS_ENABLED(CONFIG_OF) && np) {
+		struct musb_hdrc_config *config;
+		struct musb_hdrc_platform_data *data;
+		u32 phy20_refclock_freq, phy20_clkmux_cfg;
+
+		pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+		if (!pdata) {
+			ret = -ENOMEM;
+			goto err5;
+		}
+
+		data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+		if (!data) {
+			ret = -ENOMEM;
+			goto err5;
+		}
+
+		config = devm_kzalloc(&pdev->dev, sizeof(*config), GFP_KERNEL);
+		if (!config) {
+			ret = -ENOMEM;
+			goto err5;
+		}
+
+		pdata->mode = get_musb_port_mode(np);
+		config->num_eps = get_int_prop(np, "mentor,num-eps");
+		config->ram_bits = get_int_prop(np, "mentor,ram-bits");
+		/* the "mentor,power" value is in milli-amps, whereas
+		 * the mentor configuration is in 2mA units
+		 */
+		pdata->power = get_int_prop(np, "mentor,power") / 2;
+		config->multipoint = of_property_read_bool(np,
+			"mentor,multipoint");
+
+		pdata->board_data	= data;
+		pdata->config		= config;
+
+		/* optional parameter reference clock frequency */
+		if (!of_property_read_u32(np, "ti,phy20-clkmux-cfg",
+			&phy20_clkmux_cfg)) {
+			u32 cfgchip2;
+
+			/*
+			 * Select internal reference clock for USB 2.0 PHY
+			 * and use it as a clock source for USB 1.1 PHY
+			 * (this is the default setting anyway).
+			 */
+
+			cfgchip2 = __raw_readl(
+				DA8XX_SYSCFG0_VIRT(DA8XX_CFGCHIP2_REG));
+
+			cfgchip2 &= ~CFGCHIP2_USB2PHYCLKMUX;
+			cfgchip2 |=  (phy20_clkmux_cfg & 1) <<
+					CFGCHIP2_USB2PHYCLKMUX_SHIFT;
+
+			__raw_writel(cfgchip2,
+				     DA8XX_SYSCFG0_VIRT(DA8XX_CFGCHIP2_REG));
+
+		}
+
+		/* optional parameter reference clock frequency */
+		if (!of_property_read_u32(np, "ti,phy20-refclock-frequency",
+			&phy20_refclock_freq)) {
+			u32 cfgchip2;
+			int phy20_refclk_cfg;
+
+			phy20_refclk_cfg = phy_refclk_cfg(phy20_refclock_freq);
+			if (phy20_refclk_cfg < 0) {
+				dev_err(&pdev->dev,
+					"invalid PHY clock frequency %u Hz\n",
+					phy20_refclock_freq);
+				ret = -EINVAL;
+				goto err5;
+			}
+
+			/*
+			 * Set up USB clock/mode in the CFGCHIP2 register.
+			 */
+			cfgchip2 = __raw_readl(
+				DA8XX_SYSCFG0_VIRT(DA8XX_CFGCHIP2_REG));
+
+			/* USB2.0 PHY reference clock is 24 MHz */
+			cfgchip2 &= ~CFGCHIP2_REFFREQ;
+			cfgchip2 |=  phy20_refclk_cfg;
+
+			__raw_writel(cfgchip2,
+				     DA8XX_SYSCFG0_VIRT(DA8XX_CFGCHIP2_REG));
+		}
+	}
+
 	pdata->platform_ops		= &da8xx_ops;
 
 	glue->phy = usb_phy_generic_register();
@@ -627,11 +780,20 @@ static int da8xx_remove(struct platform_device *pdev)
 	return 0;
 }
 
+static const struct of_device_id da8xx_id_table[] = {
+	{
+		.compatible = "ti,da8xx-musb"
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, da8xx_id_table);
+
 static struct platform_driver da8xx_driver = {
 	.probe		= da8xx_probe,
 	.remove		= da8xx_remove,
 	.driver		= {
 		.name	= "musb-da8xx",
+		.of_match_table = of_match_ptr(da8xx_id_table),
 	},
 };
 
diff --git a/include/linux/platform_data/usb-davinci.h b/include/linux/platform_data/usb-davinci.h
index e0bc4ab..0948ce5 100644
--- a/include/linux/platform_data/usb-davinci.h
+++ b/include/linux/platform_data/usb-davinci.h
@@ -21,7 +21,8 @@
 #define CFGCHIP2_FORCE_DEVICE 	(2 << 13)
 #define CFGCHIP2_FORCE_HOST_VBUS_LOW (3 << 13)
 #define CFGCHIP2_USB1PHYCLKMUX	(1 << 12)
-#define CFGCHIP2_USB2PHYCLKMUX	(1 << 11)
+#define CFGCHIP2_USB2PHYCLKMUX_SHIFT	(11)
+#define CFGCHIP2_USB2PHYCLKMUX	(1 << CFGCHIP2_USB2PHYCLKMUX_SHIFT)
 #define CFGCHIP2_PHYPWRDN	(1 << 10)
 #define CFGCHIP2_OTGPWRDN	(1 << 9)
 #define CFGCHIP2_DATPOL 	(1 << 8)
--
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