[PATCH v7] Enable USB peripheral mode on dm365 EVM

[Constantine Shulyupin]

From: Constantine Shulyupin <const at MakeLinux.com>

Sets USB PHY clock source to 24 MHz clock.

Tested with OTG configuration, usb gadget g_zero on DM365 EVM connected to PC.

To active the patch need to call davinci_setup_usb from dm365_evm_init

References:

Definition of USB_PHY_CTRL and PHYCLKFREQ:
- http://www.makelinux.com/lib/ti/DM36x_ARM/doc-141

Original patch by miguel.aguilar at ridgerun.com three years ago:
- http://www.mail-archive.com/davinci-linux-open-source@linux.davincidsp.com/msg14741.html

Signed-off-by: Constantine Shulyupin <const at MakeLinux.com>
---

Note:

Changelog

Changes since v6
- moved call to davinci_setup_usb from dm365_evm_init to another patch accordinly request of Sergei
 
Changes since v5 http://www.spinics.net/lists/kernel/msg1413120.html
accordingy feedback of nsekhar at ti.com http://www.spinics.net/lists/kernel/msg1414914.html
- phy configuration moved to drivers/usb/musb/davinci.c
- USB_OTG configuration is submitted in separated patch: http://www.spinics.net/lists/kernel/msg1414964.html
- Setting current limit to 1000 mA. Any way the current is limited to 510 mA in davinci_setup_usb.

Changes since v4 http://www.spinics.net/lists/kernel/msg1412995.html
- removed fix of dev_info in musb_init_controller

Changes since v3 http://www.spinics.net/lists/kernel/msg1412544.html:
- removed optional altering of pr_info

Changes since v1  http://marc.info/?l=linux-kernel&m=130894150803661&w=2:
- removed optional code and reordered
- removed alternation of GPIO33, which is multiplexed with DRVVBUS, because is not need for peripheral USB

This patch is based on code from projects Arago, Angstom and RidgeRun.

---
 drivers/usb/musb/davinci.c              |    3 +++
 drivers/usb/musb/davinci.h              |    1 +

diff --git a/drivers/usb/musb/davinci.c b/drivers/usb/musb/davinci.c
index 472c8b4..af09ebf 100644
--- a/drivers/usb/musb/davinci.c
+++ b/drivers/usb/musb/davinci.c
@@ -428,6 +428,9 @@ static int davinci_musb_init(struct musb *musb)
 		__raw_writel(deepsleep, DM355_DEEPSLEEP);
 	}
 
+	if (machine_is_davinci_dm365_evm())
+		writel(readl(USB_PHY_CTRL) | USBPHY_CLKFREQ_24MHZ, USB_PHY_CTRL);
+
 	/* reset the controller */
 	musb_writel(tibase, DAVINCI_USB_CTRL_REG, 0x1);
 
diff --git a/drivers/usb/musb/davinci.h b/drivers/usb/musb/davinci.h
index 371baa0..e737d97 100644
--- a/drivers/usb/musb/davinci.h
+++ b/drivers/usb/musb/davinci.h
@@ -16,6 +16,7 @@
 
 /* Integrated highspeed/otg PHY */
 #define USBPHY_CTL_PADDR	0x01c40034
+#define USBPHY_CLKFREQ_24MHZ	BIT(13)
 #define USBPHY_DATAPOL		BIT(11)	/* (dm355) switch D+/D- */
 #define USBPHY_PHYCLKGD		BIT(8)
 #define USBPHY_SESNDEN		BIT(7)	/* v(sess_end) comparator */
-- 
1.7.9.5