Hi Anton, Kishon,

From: Anton Tikhomirov [mailto:av.tikhomirov@samsung.com]
Sent: Thursday, March 06, 2014 9:26 AM

Hi Kamil,

...

quoted

+| 3. Supporting SoCs
++--------------------
+
+To support a new SoC a new file should be added to the drivers/phy
+directory. Each SoC's configuration is stored in an instance of the
+struct samsung_usb2_phy_config.
+
+struct samsung_usb2_phy_config {
+	const struct samsung_usb2_common_phy *phys;
+	unsigned int num_phys;
+	bool has_mode_switch;

You missed rate_to_clk here.

Thank you for spotting this.

Kishon: I am sorry that this omission was made. I am happy to send an
updated patchset. However, I want to give some time for any additional
comments. Do you think that we have for this? Is today evening ok with you?

quoted

+};
+

...

quoted

diff --git a/drivers/phy/phy-samsung-usb2.c b/drivers/phy/phy-

samsung-

quoted

usb2.c new file mode 100644 index 0000000..c3b7719

--- /dev/null
+++ b/drivers/phy/phy-samsung-usb2.c

@@ -0,0 +1,222 @@
+/*
+ * Samsung SoC USB 1.1/2.0 PHY driver
+ *
+ * Copyright (C) 2013 Samsung Electronics Co., Ltd.
+ * Author: Kamil Debski <k.debski@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or

modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/clk.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include "phy-samsung-usb2.h"
+
+static int samsung_usb2_phy_power_on(struct phy *phy) {
+	struct samsung_usb2_phy_instance *inst = phy_get_drvdata(phy);
+	struct samsung_usb2_phy_driver *drv = inst->drv;
+	int ret;
+
+	dev_dbg(drv->dev, "Request to power_on \"%s\" usb phy\n",
+		inst->cfg->label);
+	ret = clk_prepare_enable(drv->clk);

clk_prepare_enable() can sleep, and therefore doesn't allow
samusng_usb2_phy_power_on() to be used in atomic context (e.g. inside
spin_lock-ed area), what sometimes may be desirable.
What about to prepare clock in probe, and just enable it here
(note: clk_enable() doesn't sleep).

From the onward discussion between you and Kishon, I draw the conclusion

that this change is not necessary. Right?

quoted

+	if (ret)
+		goto err_main_clk;
+	ret = clk_prepare_enable(drv->ref_clk);
+	if (ret)
+		goto err_instance_clk;
+	if (inst->cfg->power_on) {
+		spin_lock(&drv->lock);
+		ret = inst->cfg->power_on(inst);
+		spin_unlock(&drv->lock);
+	}
+
+	return 0;

Thank you

Best wishes,
-- 
Kamil Debski
Samsung R&D Institute Poland