On Fri, Feb 3, 2017 at 2:49 PM, Alim Akhtar [off-list ref] wrote:

Hi Kishon,


On 11/19/2015 07:09 PM, Kishon Vijay Abraham I wrote:

quoted

Hi,

On Tuesday 17 November 2015 01:41 PM, Alim Akhtar wrote:

quoted

Hi
Thanks again for looking into this.

On 11/17/2015 11:46 AM, Kishon Vijay Abraham I wrote:

quoted

Hi,

On Monday 09 November 2015 10:56 AM, Alim Akhtar wrote:

quoted

From: Seungwon Jeon <redacted>

This patch introduces Exynos UFS PHY driver. This driver
supports to deal with phy calibration and power control
according to UFS host driver's behavior.

Signed-off-by: Seungwon Jeon <redacted>
Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
Cc: Kishon Vijay Abraham I <redacted>
---
  drivers/phy/Kconfig                |    7 ++
  drivers/phy/Makefile               |    1 +
  drivers/phy/phy-exynos-ufs.c       |  241
++++++++++++++++++++++++++++++++++++
  drivers/phy/phy-exynos-ufs.h       |   85 +++++++++++++
  drivers/phy/phy-exynos7-ufs.h      |   89 +++++++++++++
  include/linux/phy/phy-exynos-ufs.h |   85 +++++++++++++
  6 files changed, 508 insertions(+)
  create mode 100644 drivers/phy/phy-exynos-ufs.c
  create mode 100644 drivers/phy/phy-exynos-ufs.h
  create mode 100644 drivers/phy/phy-exynos7-ufs.h
  create mode 100644 include/linux/phy/phy-exynos-ufs.h

diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index 7eb5859dd035..7d38a92e0297 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig

@@ -389,4 +389,11 @@ config PHY_CYGNUS_PCIE
        Enable this to support the Broadcom Cygnus PCIe PHY.
        If unsure, say N.

+config PHY_EXYNOS_UFS
+    tristate "EXYNOS SoC series UFS PHY driver"
+    depends on OF && ARCH_EXYNOS || COMPILE_TEST
+    select GENERIC_PHY
+    help
+      Support for UFS PHY on Samsung EXYNOS chipsets.
+
  endmenu

diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index 075db1a81aa5..9bec4d1a89e1 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile

@@ -10,6 +10,7 @@ obj-$(CONFIG_ARMADA375_USBCLUSTER_PHY)    +=

phy-armada375-usb2.o
  obj-$(CONFIG_BCM_KONA_USB2_PHY)        += phy-bcm-kona-usb2.o
  obj-$(CONFIG_PHY_EXYNOS_DP_VIDEO)    += phy-exynos-dp-video.o
  obj-$(CONFIG_PHY_EXYNOS_MIPI_VIDEO)    += phy-exynos-mipi-video.o
+obj-$(CONFIG_PHY_EXYNOS_UFS)    += phy-exynos-ufs.o
  obj-$(CONFIG_PHY_LPC18XX_USB_OTG)    += phy-lpc18xx-usb-otg.o
  obj-$(CONFIG_PHY_PXA_28NM_USB2)        += phy-pxa-28nm-usb2.o
  obj-$(CONFIG_PHY_PXA_28NM_HSIC)        += phy-pxa-28nm-hsic.o

diff --git a/drivers/phy/phy-exynos-ufs.c

b/drivers/phy/phy-exynos-ufs.c
new file mode 100644
index 000000000000..cb1aeaa3d4eb

--- /dev/null
+++ b/drivers/phy/phy-exynos-ufs.c

@@ -0,0 +1,241 @@
+/*
+ * UFS PHY driver for Samsung EXYNOS SoC
+ *
+ * Copyright (C) 2015 Samsung Electronics Co., Ltd.
+ * Author: Seungwon Jeon <essuuj@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or

modify
+ * it under the terms of the GNU General Public License as published
by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/phy/phy.h>
+#include <linux/phy/phy-exynos-ufs.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include "phy-exynos-ufs.h"
+
+#define for_each_phy_lane(phy, i) \
+    for (i = 0; i < (phy)->lane_cnt; i++)
+#define for_each_phy_cfg(cfg) \
+    for (; (cfg)->id; (cfg)++)
+
+#define PHY_DEF_LANE_CNT    1
+
+static void exynos_ufs_phy_config(struct exynos_ufs_phy *phy,
+            const struct exynos_ufs_phy_cfg *cfg, u8 lane)
+{
+    enum {LANE_0, LANE_1}; /* lane index */
+
+    switch (lane) {
+    case LANE_0:
+        writel(cfg->val, (phy)->reg_pma + cfg->off_0);
+        break;
+    case LANE_1:
+        if (cfg->id == PHY_TRSV_BLK)
+            writel(cfg->val, (phy)->reg_pma + cfg->off_1);
+        break;
+    }
+}
+
+static bool match_cfg_to_pwr_mode(u8 desc, u8 required_pwr)
+{
+    if (IS_PWR_MODE_ANY(desc))
+        return true;
+
+    if (IS_PWR_MODE_HS(required_pwr) && IS_PWR_MODE_HS_ANY(desc))
+        return true;
+
+    if (COMP_PWR_MODE(required_pwr, desc))
+        return true;
+
+    if (COMP_PWR_MODE_MD(required_pwr, desc) &&
+        COMP_PWR_MODE_GEAR(required_pwr, desc) &&
+        COMP_PWR_MODE_SER(required_pwr, desc))
+        return true;
+
+    return false;
+}
+
+int exynos_ufs_phy_calibrate(struct phy *phy,
+                    enum phy_cfg_tag tag, u8 pwr)

This is similar to the first version of your patch without
EXPORT_SYMBOL.

I think you have to create a new generic PHY_OPS for calibrate PHY while
making
sure that it is as generic as possible (which means calibrate_phy
shouldn't
have tag and pwr arguments or a strong justification as to why those
arguments
are required in a generic API).

I don't see the advantage to making this a generic phy_ops, this is
exynos
specific ufs-phy, please have a look at other implementations

only the implementation is specific to exynos. I've seen lot of other
vendors
want to do something like calibrate phy.

So if we add something like (*calibrate)(struct phy *phy), then it can be
used
by others as well. Russell King also want to minimize the code to program
calibration settings. So it would be good to come up with a set of
standard
bindings like 'phy,tx-swing', 'phy,emphasis', 'phy,amplitude' etc.. to
program
these settings.

quoted

drivers/phy/phy-qcom-ufs.c (which I belive mereged recently)

Thats why I hate when someone else merge PHY drivers :-( That driver can
as
well be in drivers/misc as it doesn't use PHY framework as it is supposed
to be
used. It just exports a dozen of API's to be used by controller drivers.
ick..

quoted

may be other vendors might come with there own implementation of phy.

right, it's all about providing the correct callback functions.

quoted

I am using what is currently provided by the generic phy framework.

I think for your use case, what is currently provided in the PHY framework
is
not sufficient.

Its little over a year since last time we discuss about adding a generic
calibration API. I can see in the past people tried adding *calibration* API
[1] but not sure why [1] was not landed in mainline.
Anyway now we have many users of phy_calibration API, like UFS, USB and may
be PCIe, there is a real need to add this functionality. So, here is my
approach:
 * Along with [1], we can add a void *priv for handling device specific phy
private data, and before calling phy_calibration() from phy consumer,
phy->priv is populated with private data.
This approach solves exynos-ufs-phy  calibration as well.
please have a look on the snapshot below, if you are ok, will post a proper
patch for this:

[1]: https://patchwork.kernel.org/patch/4545941/
----

Ping!!!

-- 
Regards,
Alim