[PATCH V4 1/2] Phy: Exynos: Add Exynos5250 sata phy driver
Yuvaraj Kumar
yuvaraj.cd at gmail.com
Thu Jan 2 08:33:23 EST 2014
On Tue, Dec 31, 2013 at 9:00 PM, Bartlomiej Zolnierkiewicz
<b.zolnierkie at samsung.com> wrote:
>
> [ added linux-ide ML to Cc: ]
>
> Hi,
>
> Overall the code looks good, thank you for working on this.
Thanks for the review.
>
> I still have some review comments though..
Thats Good :)
>
> On Monday, December 30, 2013 06:37:02 PM Yuvaraj Kumar C D wrote:
>> This patch adds the sata phy driver for Exynos5250.Exynos5250 sata
>> phy comprises of CMU and TRSV blocks which are of I2C register Map.
>> So this patch also adds a i2c client driver, which is used configure
>> the CMU and TRSV block of exynos5250 SATA PHY.
>>
>> This patch incorporates the generic phy framework to deal with sata
>> phy.
>
> Two minor nits here:
>
> - Some consistency in using of "SATA", "PHY" and "Exynos" would be
> nice, i.e.:
>
> s/sata/SATA/
> s/phy/PHY/
> s/exynos/Exynos/
Ok
>
> - Please add two spaces after each "." and before new sentence.
Ok
>
>> This patch depends on the below patches
>> [1].drivers: phy: add generic PHY framework
>> by Kishon Vijay Abraham I<kishon at ti.com>
>> [2].ata: ahci_platform: Manage SATA PHY
>> by Roger Quadros <rogerq at ti.com>
>>
>> Signed-off-by: Yuvaraj Kumar C D <yuvaraj.cd at samsung.com>
>> Signed-off-by: Girish K S <ks.giri at samsung.com>
>> Signed-off-by: Vasanth Ananthan <vasanth.a at samsung.com>
>> ---
>> Changes from V3:
>> 1.Moved devm_phy_create before to devm_phy_provider_register.
>>
>> Changes from V2:
>> 1.Removed of_match_table
>> 2.Moved to syscon interface for PMU handling.
>>
>> Changes from V1:
>> 1.Adapted to latest version of Generic PHY framework
>> 2.Removed exynos_sata_i2c_remove function.
>>
>>
>> drivers/phy/Kconfig | 11 ++
>> drivers/phy/Makefile | 1 +
>> drivers/phy/exynos5250_phy_i2c.c | 44 ++++++++
>> drivers/phy/sata_phy_exynos5250.c | 220 +++++++++++++++++++++++++++++++++++++
>
> For consistency with other PHY drivers this file should be named
> diffirently (phy-exynos5250-sata.c).
>
>> drivers/phy/sata_phy_exynos5250.h | 35 ++++++
>> 5 files changed, 311 insertions(+)
>> create mode 100644 drivers/phy/exynos5250_phy_i2c.c
>> create mode 100644 drivers/phy/sata_phy_exynos5250.c
>> create mode 100644 drivers/phy/sata_phy_exynos5250.h
>>
>> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
>> index d0611b8..6ea124d 100644
>> --- a/drivers/phy/Kconfig
>> +++ b/drivers/phy/Kconfig
>> @@ -57,4 +57,15 @@ config PHY_EXYNOS_DP_VIDEO
>> help
>> Support for Display Port PHY found on Samsung EXYNOS SoCs.
>>
>> +config EXYNOS5250_SATA_PHY
>
> I think that for consistency with other config options it should be
> named PHY_EXYNOS5250_SATA instead.
Yup.I will change.
>
>> + tristate "Exynos5250 Sata SerDes/PHY driver"
>> + depends on SOC_EXYNOS5250
>> + select GENERIC_PHY
>> + select MFD_SYSCON if ARCH_EXYNOS5
>
> "if ARCH_EXYNOS5" check shouldn't be needed given SOC_EXYNOS5250
> dependency.
Ok
>
>> + help
>> + Enable this to support SATA SerDes/Phy found on Samsung's
>> + Exynos5250 based SoCs.This SerDes/Phy supports SATA 1.5 Gb/s,
>> + SATA 3.0 Gb/s, SATA 6.0 Gb/s speeds.It supports one SATA host
>> + port to accept one SATA device.
>> +
>> endmenu
>> diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
>> index 4e4adc9..b73eb73 100644
>> --- a/drivers/phy/Makefile
>> +++ b/drivers/phy/Makefile
>> @@ -8,3 +8,4 @@ obj-$(CONFIG_PHY_EXYNOS_MIPI_VIDEO) += phy-exynos-mipi-video.o
>> obj-$(CONFIG_PHY_MVEBU_SATA) += phy-mvebu-sata.o
>> obj-$(CONFIG_OMAP_USB2) += phy-omap-usb2.o
>> obj-$(CONFIG_TWL4030_USB) += phy-twl4030-usb.o
>> +obj-$(CONFIG_EXYNOS5250_SATA_PHY) += sata_phy_exynos5250.o exynos5250_phy_i2c.o
>
> Will this compile/work without I2C support?
No.I missed this.It will not compile without I2C support.
How about below change in drivers/phy/Kconfig ?
config EXYNOS5250_SATA_PHY
select I2C
select I2C_S3C2410
>
> CONFIG_EXYNOS5250_SATA_PHY doesn't require it currently.
I didnt get this. what it doesn't require?
>
>> diff --git a/drivers/phy/exynos5250_phy_i2c.c b/drivers/phy/exynos5250_phy_i2c.c
>> new file mode 100644
>> index 0000000..c0c1150
>> --- /dev/null
>> +++ b/drivers/phy/exynos5250_phy_i2c.c
>> @@ -0,0 +1,44 @@
>> +/*
>> + * Copyright (C) 2013 Samsung Electronics Co.Ltd
>> + * Author:
>> + * Yuvaraj C D <yuvaraj.cd at samsung.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/i2c.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>
> Please add a newline here.
Ok
>
>> +#include "sata_phy_exynos5250.h"
>> +
>> +static int exynos_sata_i2c_probe(struct i2c_client *client,
>> + const struct i2c_device_id *i2c_id)
>> +{
>> + int ret = 0;
>
> No need to initialize "ret", also please add a newline here.
Ok
>
>> + ret = sataphy_attach_i2c_client(client);
>> + if (ret < 0)
>> + return ret;
>> +
>> + dev_info(&client->adapter->dev,
>> + "attached %s into sataphy i2c adapter successfully\n",
>> + client->name);
>> +
>> + return ret;
>> +}
>> +
>> +static const struct i2c_device_id sataphy_i2c_device_match[] = {
>> + { "exynos-sataphy-i2c", 0 },
>> +};
>> +
>> +struct i2c_driver sataphy_i2c_driver = {
>
> Keeping it global together with sataphy_attach_i2c_client() is not very
> nice. I've talked with our local device tree guru (a.k.a. Tomasz Figa)
> about this and it may be that this i2c driver is not even necessary.
Can you elaborate more on this?
>
> If you manage to extract i2c adapter and address data from the device
> tree (using proper of_* methods) they can be used instead of i2c client
> data in the SATA PHY driver.
I think the above is true, if the complete SATA PHY controller sits on
the i2c adapter.
But in Exynos5250 case,only the few configurations ( CMU and TRSV
blocks ) SATA PHY
are done through I2C(channel 9). Correct me if i am wrong.
>
>> + .probe = exynos_sata_i2c_probe,
>> + .id_table = sataphy_i2c_device_match,
>> + .driver = {
>> + .name = "exynos-sataphy-i2c",
>> + .owner = THIS_MODULE,
>> + },
>> +};
>> diff --git a/drivers/phy/sata_phy_exynos5250.c b/drivers/phy/sata_phy_exynos5250.c
>> new file mode 100644
>> index 0000000..0765863
>> --- /dev/null
>> +++ b/drivers/phy/sata_phy_exynos5250.c
>> @@ -0,0 +1,220 @@
>> +/*
>> + * Samsung SATA SerDes(PHY) driver
>> + *
>> + * Copyright (C) 2013 Samsung Electronics Co., Ltd.
>> + * Authors: Girish K S <ks.giri at samsung.com>
>> + * Yuvaraj Kumar C D <yuvaraj.cd at 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/delay.h>
>> +#include <linux/io.h>
>> +#include <linux/i2c.h>
>> +#include <linux/kernel.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/regmap.h>
>> +#include <linux/spinlock.h>
>> +#include <linux/mfd/syscon.h>
>
> Please add a newline here.
Ok
>
>> +#include "sata_phy_exynos5250.h"
>> +
>> +static struct i2c_client *phy_i2c_client;
>> +
>> +struct exynos_sata_phy {
>> + struct phy *phy;
>> + struct clk *phyclk;
>> + void __iomem *regs;
>> + void __iomem *pmureg;
>> +};
>> +
>> +static bool wait_for_reg_status(void __iomem *base, u32 reg, u32 checkbit,
>> + u32 status)
>> +{
>> + unsigned long timeout = jiffies + usecs_to_jiffies(1000);
>
> ditto
Ok
>
>> + while (time_before(jiffies, timeout)) {
>> + if ((readl(base + reg) & checkbit) == status)
>> + return true;
>> + }
>
> ditto
Ok
>
>> + return false;
>> +}
>> +
>> +int sataphy_attach_i2c_client(struct i2c_client *sata_phy)
>
> sata_phy is not a best variable name here, maybe just use "client"
> instead?
Ok
>
>> +{
>> + if (!sata_phy)
>> + return -EPROBE_DEFER;
>> + else
>> + phy_i2c_client = sata_phy;
>> +
>> + return 0;
>> +}
>> +
>> +static int exynos_sata_phy_power_on(struct phy *phy)
>> +{
>> + struct exynos_sata_phy *sata_phy = phy_get_drvdata(phy);
>> +
>> + if (sata_phy->pmureg)
>
> No need to check it, exynos_sata_phy_probe() fails early if pmureg
> cannot be find.
Ok
>
>> + regmap_update_bits(sata_phy->pmureg, SATAPHY_CONTROL_OFFSET,
>> + EXYNOS5_SATAPHY_PMU_ENABLE, EXYNOS_SATA_PHY_EN);
>> +
>> + return 0;
>> +}
>> +
>> +static int exynos_sata_phy_power_off(struct phy *phy)
>> +{
>> + struct exynos_sata_phy *sata_phy = phy_get_drvdata(phy);
>> +
>> + if (sata_phy->pmureg)
>
> ditto
Ok
>
>> + regmap_update_bits(sata_phy->pmureg, SATAPHY_CONTROL_OFFSET,
>> + EXYNOS5_SATAPHY_PMU_ENABLE, ~EXYNOS_SATA_PHY_EN);
>> +
>> + return 0;
>> +}
>> +
>> +static int exynos_sata_phy_init(struct phy *phy)
>> +{
>> + u32 val = 0;
>> + int ret = 0;
>> + u8 buf[] = { 0x3A, 0x0B };
>> + struct exynos_sata_phy *sata_phy = phy_get_drvdata(phy);
>> +
>> + if (sata_phy->pmureg)
>
> ditto
Ok
>
>> + regmap_update_bits(sata_phy->pmureg, SATAPHY_CONTROL_OFFSET,
>> + EXYNOS5_SATAPHY_PMU_ENABLE, EXYNOS_SATA_PHY_EN);
>> +
>> + writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
>> +
>> + val = readl(sata_phy->regs + EXYNOS5_SATA_RESET);
>> + val |= 0xFF;
>> + writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
>> +
>> + val = readl(sata_phy->regs + EXYNOS5_SATA_RESET);
>> + val |= LINK_RESET;
>> + writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
>> +
>> + val = readl(sata_phy->regs + EXYNOS5_SATA_RESET);
>> + val |= RESET_CMN_RST_N;
>> + writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
>
> Please add a newline here.
Ok
>
>> + val = readl(sata_phy->regs + EXYNOS5_SATA_PHSATA_CTRLM);
>> + val &= ~PHCTRLM_REF_RATE;
>> + writel(val, sata_phy->regs + EXYNOS5_SATA_PHSATA_CTRLM);
>> +
>> + /* High speed enable for Gen3 */
>> + val = readl(sata_phy->regs + EXYNOS5_SATA_PHSATA_CTRLM);
>> + val |= PHCTRLM_HIGH_SPEED;
>> + writel(val, sata_phy->regs + EXYNOS5_SATA_PHSATA_CTRLM);
>> +
>> + val |= CTRL0_P0_PHY_CALIBRATED_SEL | CTRL0_P0_PHY_CALIBRATED;
>
> This doesn't look correct. The "val" variable still contains value
> used previously for PHCTRLM register and now (after setting bits 8-9)
> it will be reused for CTRL0 register. I believe that there is a
>
> val = readl(sata_phy->regs + EXYNOS5_SATA_CTRL0);
>
> missing here.
Yes,I will change.
>
>> + writel(val, sata_phy->regs + EXYNOS5_SATA_CTRL0);
>> +
>> + writel(0x2, sata_phy->regs + EXYNOS5_SATA_MODE0);
>
> Please add a define instead of using a magic number. Morever the code
> should read the content of MODE0 register first and then set bit1 (in
> the documentation that I have bits 2-31 are marked as Reserved, which
> means that they are not necessarily hard-wired to zero).
Ok.
>
> Also:
>
> This code sets PHY# speed mode to 6.0 Gb/s. Does this setting need to
> be updated when 3.0 Gb/s or 1.5 Gb/s devices are used instead? Do such
> devices work fine with the current code?
No,ahci driver will do that.If it could not able to detect the device
with 6.0Gb/s
it tries for the lower speed and detect the device.
>
> [ There is a patch adding set_speed method to the generic PHY framework:
>
> http://permalink.gmane.org/gmane.linux.scsi/86660
>
> but AHCI platform driver would still need to be updated to use it. ]
>
>> + ret = i2c_master_send(phy_i2c_client, buf, sizeof(buf));
>> + if (ret < 0)
>> + return -ENXIO;
>> +
>> + /* release cmu reset */
>> + val = readl(sata_phy->regs + EXYNOS5_SATA_RESET);
>> + val &= ~RESET_CMN_RST_N;
>> + writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
>> +
>> + val = readl(sata_phy->regs + EXYNOS5_SATA_RESET);
>> + val |= RESET_CMN_RST_N;
>> + writel(val, sata_phy->regs + EXYNOS5_SATA_RESET);
>> +
>> + return (wait_for_reg_status(sata_phy->regs, EXYNOS5_SATA_PHSATA_STATM,
>> + PHSTATM_PLL_LOCKED, 1)) ? 0 : -EINVAL;
>> +
>> +}
>> +
>> +static struct phy_ops exynos_sata_phy_ops = {
>> + .init = exynos_sata_phy_init,
>> + .power_on = exynos_sata_phy_power_on,
>> + .power_off = exynos_sata_phy_power_off,
>> + .owner = THIS_MODULE,
>> +};
>> +
>> +static int exynos_sata_phy_probe(struct platform_device *pdev)
>> +{
>> + struct exynos_sata_phy *sata;
>
> Why not name it sata_phy like in other functions?
>
>> + struct device *dev = &pdev->dev;
>> + struct resource *res;
>> + struct phy_provider *phy_provider;
>> + int ret = 0;
>> +
>> + sata = devm_kzalloc(dev, sizeof(*sata), GFP_KERNEL);
>> + if (!sata)
>> + return -ENOMEM;
>> +
>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +
>> + sata->regs = devm_ioremap_resource(dev, res);
>> + if (IS_ERR(sata->regs))
>> + return PTR_ERR(sata->regs);
>> +
>> + sata->pmureg = syscon_regmap_lookup_by_phandle(dev->of_node,
>> + "samsung,syscon-phandle");
>> + if (!sata->pmureg) {
>> + dev_err(dev, "syscon regmap lookup failed.\n");
>> + return PTR_ERR(sata->pmureg);
>> + }
>> + dev_set_drvdata(dev, sata);
>> +
>> + if (i2c_add_driver(&sataphy_i2c_driver)) {
>> + dev_err(dev, "failed to register sataphy i2c driver\n");
>> + return -ENOENT;
>> + }
>> +
>> + sata->phyclk = devm_clk_get(dev, "sata_phyctrl");
>> + if (IS_ERR(sata->phyclk)) {
>
> Don't we need to also unregister i2c driver on failure?
Yes needed.Will change.
>
>> + dev_err(dev, "failed to get clk for PHY\n");
>> + return PTR_ERR(sata->phyclk);
>> + }
>> +
>> + ret = clk_prepare_enable(sata->phyclk);
>> + if (ret < 0) {
>
> ditto
Ok
>
>> + dev_err(dev, "failed to enable source clk\n");
>> + return ret;
>> + }
>> +
>> + sata->phy = devm_phy_create(dev, &exynos_sata_phy_ops, NULL);
>> + if (IS_ERR(sata->phy)) {
>
> ditto + clk_disable_unprepare(sata->phyclk)
Ok
>
>> + dev_err(dev, "failed to create PHY\n");
>> + return PTR_ERR(sata->phy);
>> + }
>> +
>> + phy_provider = devm_of_phy_provider_register(dev,
>> + of_phy_simple_xlate);
>> + if (IS_ERR(phy_provider))
>
> ditto
Ok
>
>> + return PTR_ERR(phy_provider);
>> +
>> + phy_set_drvdata(sata->phy, sata);
>> + return 0;
>> +}
>> +
>> +static const struct of_device_id exynos_sata_phy_of_match[] = {
>> + { .compatible = "samsung,exynos5250-sata-phy" },
>> + { },
>> +};
>> +MODULE_DEVICE_TABLE(of, exynos_sata_phy_of_match);
>> +
>> +static struct platform_driver exynos_sata_phy_driver = {
>> + .probe = exynos_sata_phy_probe,
>> + .driver = {
>> + .of_match_table = exynos_sata_phy_of_match,
>> + .name = "samsung,sata-phy",
>> + .owner = THIS_MODULE,
>> + }
>> +};
>> +module_platform_driver(exynos_sata_phy_driver);
>> +
>> +MODULE_DESCRIPTION("Samsung SerDes PHY driver");
>> +MODULE_LICENSE("GPL");
>> +MODULE_AUTHOR("ks.giri <ks.giri at samsung.com>");
>> +MODULE_AUTHOR("Yuvaraj C D <yuvaraj.cd at samsung.com>");
>> diff --git a/drivers/phy/sata_phy_exynos5250.h b/drivers/phy/sata_phy_exynos5250.h
>> new file mode 100644
>> index 0000000..3e2089d
>> --- /dev/null
>> +++ b/drivers/phy/sata_phy_exynos5250.h
>> @@ -0,0 +1,35 @@
>> +/*
>> + *
>> + * Copyright (c) 2013 Samsung Electronics Co., Ltd.
>> + * Author:
>> + * Yuvaraj Kumar C D<yuvaraj.cd at samsung.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.
>> + */
>> +
>> +#define EXYNOS5_SATA_RESET 0x4
>> +#define EXYNOS5_SATA_MODE0 0x10
>> +#define EXYNOS5_SATA_CTRL0 0x14
>> +#define EXYNOS5_SATA_STAT0 0x18
>
> This one seems to be unused and can be removed.
Ok
>
>> +#define EXYNOS5_SATA_PHSATA_CTRLM 0xE0
>> +#define EXYNOS5_SATA_PHSATA_CTRL0 0xE4
>
> ditto
Ok
>
>> +#define EXYNOS5_SATA_PHSATA_STATM 0xF0
>> +#define EXYNOS5_SATA_PHSTAT0 0xF4
>
> ditto
Ok
>
>> +#define RESET_CMN_RST_N (1 << 1)
>> +#define LINK_RESET 0xF0000
>> +#define CTRL0_P0_PHY_CALIBRATED_SEL (1 << 9)
>> +#define CTRL0_P0_PHY_CALIBRATED (1 << 8)
>> +#define PHCTRLM_REF_RATE (1 << 1)
>> +#define PHCTRLM_HIGH_SPEED (1 << 0)
>> +#define PHSTATM_PLL_LOCKED (1 << 0)
>> +#define SATA_PHY_CON_RESET (LINK_RESET | 3F)
>
> ditto (LINK_RESET can also be removed)
SATA_PHY_CON_RESET can be removed.But LINK_RESET required.
>
>> +#define EXYNOS_SATA_PHY_EN (1 << 0)
>> +#define SATAPHY_CONTROL_OFFSET 0x0724
>> +#define EXYNOS5_SATAPHY_PMU_ENABLE (1 << 0)
>
> All above defines can be moved into the SATA PHY driver as they are
> not intended to be shared with other code.
Ok
>
> To make the code easier to read you can also group the defines for
> specific register below this register offset define, i.e.:
>
> #define EXYNOS5_SATA_RESET 0x4
> #define RESET_CMN_RST_N (1 << 1)
> #define LINK_RESET 0xF0000
> #define EXYNOS5_SATA_MODE0 0x10
Ok
> ...
>
>> +int sataphy_attach_i2c_client(struct i2c_client *sata_phy);
>> +extern struct i2c_driver sataphy_i2c_driver;
>
> Best regards,
> --
> Bartlomiej Zolnierkiewicz
> Samsung R&D Institute Poland
> Samsung Electronics
>
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