[RFC 4/8] usb: phy: move TCSR driver into new file

From: Arnd Bergmann
Date: Wed May 18 2016 - 17:25:15 EST


The phy-msm-usb driver open-codes access to the Top Control and Status
Register area for setting the phy mode, without any serialization or
checks if these registers are actually present.

This moves the hack to a more prominent location in the hope that it
can eventually get cleaned up.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/soc/qcom/Kconfig | 6 +++++
drivers/soc/qcom/Makefile | 1 +
drivers/soc/qcom/qcom-tcsr.c | 57 ++++++++++++++++++++++++++++++++++++++++
drivers/usb/phy/Kconfig | 1 +
drivers/usb/phy/phy-msm-usb.c | 10 +++----
include/linux/soc/qcom/tcsr.h | 13 +++++++++
include/linux/usb/msm_hsusb_hw.h | 3 ---
7 files changed, 81 insertions(+), 10 deletions(-)
create mode 100644 drivers/soc/qcom/qcom-tcsr.c
create mode 100644 include/linux/soc/qcom/tcsr.h

diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
index 461b387d03cc..37fe433d49db 100644
--- a/drivers/soc/qcom/Kconfig
+++ b/drivers/soc/qcom/Kconfig
@@ -76,3 +76,9 @@ config QCOM_WCNSS_CTRL
help
Client driver for the WCNSS_CTRL SMD channel, used to download nv
firmware to a newly booted WCNSS chip.
+
+config QCOM_TCSR
+ bool
+ help
+ This is a driver for the "Top Control and Status Register" area,
+ and is used by the usb PHY driver.
diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
index fdd664edf0bd..672d392aa6c4 100644
--- a/drivers/soc/qcom/Makefile
+++ b/drivers/soc/qcom/Makefile
@@ -6,4 +6,5 @@ obj-$(CONFIG_QCOM_SMEM) += smem.o
obj-$(CONFIG_QCOM_SMEM_STATE) += smem_state.o
obj-$(CONFIG_QCOM_SMP2P) += smp2p.o
obj-$(CONFIG_QCOM_SMSM) += smsm.o
+obj-$(CONFIG_QCOM_TCSR) += qcom-tcsr.o
obj-$(CONFIG_QCOM_WCNSS_CTRL) += wcnss_ctrl.o
diff --git a/drivers/soc/qcom/qcom-tcsr.c b/drivers/soc/qcom/qcom-tcsr.c
new file mode 100644
index 000000000000..fdb4ed762292
--- /dev/null
+++ b/drivers/soc/qcom/qcom-tcsr.c
@@ -0,0 +1,57 @@
+/*
+ * This abstracts the TCSR register area in Qualcomm SoCs, originally
+ * introduced by Tim Bird as part of the phy-msm-usb.ko device driver,
+ * and split out by Arnd Bergmann into a separate file.
+ *
+ * This file shouldn't really exist, since we have no way to detect
+ * if the TCSR actually exists in the hardcoded location, or if it
+ * is compatible with the version that was originally used.
+ *
+ * If the assumptions ever change, we have to come up with a better
+ * solution.
+ */
+#include <linux/module.h>
+#include <linux/io.h>
+
+/* USB phy selector - in TCSR address range */
+#define USB2_PHY_SEL 0xfd4ab000
+
+/*
+ * qcom_tcsr_phy_sel -- Select secondary PHY via TCSR
+ *
+ * Select the secondary PHY using the TCSR register, if phy-num=1
+ * in the DTS (or phy_number is set in the platform data). The
+ * SOC has 2 PHYs which can be used with the OTG port, and this
+ * code allows configuring the correct one.
+ *
+ * Note: This resolves the problem I was seeing where I couldn't
+ * get the USB driver working at all on a dragonboard, from cold
+ * boot. This patch depends on patch 5/14 from Ivan's msm USB
+ * patch set. It does not use DT for the register address, as
+ * there's no evidence that this address changes between SoC
+ * versions.
+ * - Tim
+ */
+int qcom_tcsr_phy_sel(u32 val)
+{
+ void __iomem *phy_select;
+ int ret;
+
+ phy_select = ioremap(USB2_PHY_SEL, 4);
+
+ if (!phy_select) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ /* Enable second PHY with the OTG port */
+ writel(0x1, phy_select);
+ ret = 0;
+out:
+ iounmap(phy_select);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(qcom_tcsr_phy_sel);
+
+MODULE_AUTHOR("Tim Bird <tbird20d@xxxxxxxxx>");
+MODULE_DESCRIPTION("Qualcomm TCSR abstraction");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
index c6904742e2aa..5427f48973cf 100644
--- a/drivers/usb/phy/Kconfig
+++ b/drivers/usb/phy/Kconfig
@@ -143,6 +143,7 @@ config USB_MSM_OTG
depends on RESET_CONTROLLER
depends on EXTCON
select USB_PHY
+ select QCOM_TCSR if ARCH_QCOM
help
Enable this to support the USB OTG transceiver on Qualcomm chips. It
handles PHY initialization, clock management, and workarounds
diff --git a/drivers/usb/phy/phy-msm-usb.c b/drivers/usb/phy/phy-msm-usb.c
index 8a34759727bb..f559d73fd7bc 100644
--- a/drivers/usb/phy/phy-msm-usb.c
+++ b/drivers/usb/phy/phy-msm-usb.c
@@ -31,6 +31,7 @@
#include <linux/uaccess.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
+#include <linux/soc/qcom/tcsr.h>
#include <linux/pm_runtime.h>
#include <linux/of.h>
#include <linux/of_device.h>
@@ -1820,7 +1821,6 @@ static int msm_otg_probe(struct platform_device *pdev)
struct resource *res;
struct msm_otg *motg;
struct usb_phy *phy;
- void __iomem *phy_select;

motg = devm_kzalloc(&pdev->dev, sizeof(struct msm_otg), GFP_KERNEL);
if (!motg)
@@ -1882,13 +1882,9 @@ static int msm_otg_probe(struct platform_device *pdev)
* the dwc3 driver does not set this bit in an incompatible way.
*/
if (motg->phy_number) {
- phy_select = devm_ioremap_nocache(&pdev->dev, USB2_PHY_SEL, 4);
- if (!phy_select) {
- ret = -ENOMEM;
+ ret = qcom_tcsr_phy_sel(0x1);
+ if (ret)
goto unregister_extcon;
- }
- /* Enable second PHY with the OTG port */
- writel(0x1, phy_select);
}

dev_info(&pdev->dev, "OTG regs = %p\n", motg->regs);
diff --git a/include/linux/soc/qcom/tcsr.h b/include/linux/soc/qcom/tcsr.h
new file mode 100644
index 000000000000..7332a07806ca
--- /dev/null
+++ b/include/linux/soc/qcom/tcsr.h
@@ -0,0 +1,13 @@
+#ifndef __QCOM_TCSR_H
+#define __QCOM_TCSR_H
+
+#ifdef CONFIG_QCOM_TCSR
+int qcom_tcsr_phy_sel(u32 val);
+#else
+static inline int qcom_tcsr_phy_sel(u32 val)
+{
+ return 0;
+}
+#endif
+
+#endif
diff --git a/include/linux/usb/msm_hsusb_hw.h b/include/linux/usb/msm_hsusb_hw.h
index 974c3796a23f..368e94389bf1 100644
--- a/include/linux/usb/msm_hsusb_hw.h
+++ b/include/linux/usb/msm_hsusb_hw.h
@@ -16,9 +16,6 @@
#ifndef __LINUX_USB_GADGET_MSM72K_UDC_H__
#define __LINUX_USB_GADGET_MSM72K_UDC_H__

-/* USB phy selector - in TCSR address range */
-#define USB2_PHY_SEL 0xfd4ab000
-
#define USB_AHBBURST (MSM_USB_BASE + 0x0090)
#define USB_AHBMODE (MSM_USB_BASE + 0x0098)
#define USB_GENCONFIG_2 (MSM_USB_BASE + 0x00a0)
--
2.7.0