[PATCH v3 0/3] ahci: enable ahci sata support on imx6q

[PATCH v3 0/3] ahci: enable ahci sata support on imx6q

[Richard Zhu]

v3: add imx6q specific ahci sata support
  - Keep arch/arm and ahci_platform driver clean.
  - Add the sata_imx standalone driver contained all the
  specific setup
  - Add the release function, support the loadable module
  driver.
  - Tested on imx6q sd board.

v2: http://www.spinics.net/lists/linux-ide/msg45666.html 
 - Setup standalone imx ahci sata driver, because of
 the misalignments of the bits definition of the HBA register.
 - Replace the node by the label in the board dts.
 - 

v1: http://www.spinics.net/lists/linux-ide/msg45581.html
 - add imx6q specific ahci sata support to arch/arm/mach-imx/mach-imx6q.c

These patches is based on imx/dt branch of
"http://git.linaro.org/git-ro/people/shawnguo/linux-2.6.git"

[v3 1/3] ARM: dtsi: enable ahci sata on imx6q platforms
[v3 2/3] ARM: imx6q: update the sata bits definitions of gpr13
[v3 3/3] sata: imx: add ahci sata support on imx platforms

arch/arm/boot/dts/imx6q-sabreauto.dts       |    4 +
arch/arm/boot/dts/imx6q-sabrelite.dts       |    4 +
arch/arm/boot/dts/imx6q-sabresd.dts         |    4 +
arch/arm/boot/dts/imx6q.dtsi                |    9 +
drivers/ata/Kconfig                         |    9 +
drivers/ata/Makefile                        |    1 +
drivers/ata/sata_imx.c                      |  221 +++++++++++++++++++++++++++
include/linux/mfd/syscon/imx6q-iomuxc-gpr.h |  121 ++++++++++-----
8 files changed, 336 insertions(+), 37 deletions(-)

[v3 3/3] sata: imx: add ahci sata support on imx platforms

[Sascha Hauer]

On Fri, Jul 05, 2013 at 05:52:22PM +0800, Richard Zhu wrote:
> From: Richard Zhu <r65037@freescale.com>
> 
> imx6q contains one Synopsys AHCI SATA controller,
> But it can't shares ahci_platform driver with other
> controllers.
> Because there are some misalignments of the bits
> definitions of the HBA registers and the Vendor
> Specific registers
>  - CAP_SSS(bit20) of the HOST_CAP is writable, default
>  value is '0', should be configured to be '1'
>  - bit0 (only one AHCI SATA port on imx6q) of the
>  HOST_PORTS_IMPL should be set to be '1'.(default 0)
>  - One Vendor Specific register HOST_TIMER1MS(offset:0xe0)
>  should be configured regarding to the frequency of AHB
>  bus clock.
>  - Configurations of the AHCI PHY clock, and the signal
>  parameters of the GPR13
> 
> Setup its own ahci sata driver, enable the imx6q ahci
> sata support.
> 
> Signed-off-by: Richard Zhu <r65037@freescale.com>
> ---
>  drivers/ata/Kconfig    |    9 ++
>  drivers/ata/Makefile   |    1 +
>  drivers/ata/sata_imx.c |  230 ++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 240 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/ata/sata_imx.c
> 
> diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig
> index a5a3ebc..45ed2f0 100644
> --- a/drivers/ata/Kconfig
> +++ b/drivers/ata/Kconfig
> @@ -97,6 +97,15 @@ config SATA_AHCI_PLATFORM
>  
>  	  If unsure, say N.
>  
> +config SATA_IMX
> +	tristate "Freescale iMX AHCI SATA support"

It's rather untypical to write iMX. Please write i.MX.

> +	depends on SATA_AHCI_PLATFORM
> +	help
> +	  This option enables support for the Freescale iMX SoC's
> +	  onboard AHCI SATA.
> +
> +	  If unsure, say N.
> +
>  config SATA_FSL
>  	tristate "Freescale 3.0Gbps SATA support"
>  	depends on FSL_SOC
> diff --git a/drivers/ata/Makefile b/drivers/ata/Makefile
> index c04d0fd..04b1c6c 100644
> --- a/drivers/ata/Makefile
> +++ b/drivers/ata/Makefile
> @@ -10,6 +10,7 @@ obj-$(CONFIG_SATA_INIC162X)	+= sata_inic162x.o
>  obj-$(CONFIG_SATA_SIL24)	+= sata_sil24.o
>  obj-$(CONFIG_SATA_DWC)		+= sata_dwc_460ex.o
>  obj-$(CONFIG_SATA_HIGHBANK)	+= sata_highbank.o libahci.o
> +obj-$(CONFIG_SATA_IMX)		+= sata_imx.o
>  
>  # SFF w/ custom DMA
>  obj-$(CONFIG_PDC_ADMA)		+= pdc_adma.o
> diff --git a/drivers/ata/sata_imx.c b/drivers/ata/sata_imx.c
> new file mode 100644
> index 0000000..a129efb
> --- /dev/null
> +++ b/drivers/ata/sata_imx.c
> @@ -0,0 +1,230 @@
> +/*
> + * Freescale IMX AHCI SATA platform driver
> + * Copyright 2013 Freescale Semiconductor, Inc.
> + *
> + * based on the AHCI SATA platform driver by Jeff Garzik and Anton Vorontsov
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program. If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/kernel.h>
> +#include <linux/gfp.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/device.h>
> +#include <linux/platform_device.h>
> +#include <linux/libata.h>
> +#include <linux/ahci_platform.h>
> +#include <linux/of_device.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
> +#include "ahci.h"
> +#include <linux/clk-private.h>

Do you need anything from clk-private.h? You shouldn't.

> +
> +enum {
> +	HOST_TIMER1MS = 0xe0, /* Timer 1-ms */
> +};
> +
> +/* imx6q ahci module initialization. */
> +static int imx6q_sata_phy_clk(struct device *dev, int enable)
> +{
> +	int ret = 0;
> +	struct clk *sata_ref_clk;
> +
> +	sata_ref_clk = devm_clk_get(dev, "sata_ref_100m");
> +	if (IS_ERR(sata_ref_clk)) {
> +		dev_err(dev, "can't get sata_ref clock.\n");
> +		return PTR_ERR(sata_ref_clk);
> +	}

clk_get must be balanced with clk_put. You need to have some private
data and keep a pointer to the clock.

> +	if (enable) {
> +		/* Enable PHY clock */
> +		ret = clk_prepare_enable(sata_ref_clk);
> +		if (ret < 0)
> +			dev_err(dev, "can't prepare-enable sata_ref clock\n");

When printing error messages it's always helpful to print the error code
aswell.

> +	} else {
> +		/* Disable PHY clock */

This comment (also the one above enable) doesn't contain any useful
information.

> +		clk_disable_unprepare(sata_ref_clk);
> +	}
> +
> +	return ret;
> +}
> +
> +static int imx6q_sata_init(struct device *dev, void __iomem *mmio)
> +{
> +	int ret = 0;
> +	struct regmap *gpr;
> +	struct clk *ahb_clk;
> +
> +	ret = imx6q_sata_phy_clk(dev, true);
> +	if (ret < 0)
> +		return ret;
> +
> +	gpr = syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr");
> +	if (IS_ERR(gpr)) {
> +		dev_err(dev, "failed to find fsl,imx6q-iomux-gpr regmap\n");
> +		return PTR_ERR(gpr);
> +	}
> +
> +	/*
> +	 * set PHY Paremeters, two steps to configure the GPR13,
> +	 * one write for rest of parameters, mask of first write
> +	 * is 0x07fffffd, and the other one write for setting
> +	 * the mpll_clk_en.
> +	 */
> +	regmap_update_bits(gpr, 0x34, IMX6Q_GPR13_SATA_RX_EQ_VAL_MASK
> +			| IMX6Q_GPR13_SATA_RX_LOS_LVL_MASK
> +			| IMX6Q_GPR13_SATA_RX_DPLL_MODE_MASK
> +			| IMX6Q_GPR13_SATA_SPD_MODE_MASK
> +			| IMX6Q_GPR13_SATA_MPLL_SS_EN
> +			| IMX6Q_GPR13_SATA_TX_ATTEN_MASK
> +			| IMX6Q_GPR13_SATA_TX_BOOST_MASK
> +			| IMX6Q_GPR13_SATA_TX_LVL_MASK
> +			| IMX6Q_GPR13_SATA_TX_EDGE_RATE
> +			, IMX6Q_GPR13_SATA_RX_EQ_VAL_3_0_DB
> +			| IMX6Q_GPR13_SATA_RX_LOS_LVL_SATA2M
> +			| IMX6Q_GPR13_SATA_RX_DPLL_MODE_2P_4F
> +			| IMX6Q_GPR13_SATA_SPD_MODE_3P0G
> +			| IMX6Q_GPR13_SATA_MPLL_SS_EN
> +			| IMX6Q_GPR13_SATA_TX_ATTEN_9_16
> +			| IMX6Q_GPR13_SATA_TX_BOOST_3_33_DB
> +			| IMX6Q_GPR13_SATA_TX_LVL_1_025_V);
> +	regmap_update_bits(gpr, 0x34, IMX6Q_GPR13_SATA_MPLL_CLK_EN,
> +			IMX6Q_GPR13_SATA_MPLL_CLK_EN);
> +	usleep_range(100, 200);
> +
> +	/*
> +	 * Configure the HWINIT bits of the HOST_CAP and HOST_PORTS_IMPL,
> +	 * and IP vendor specific register HOST_TIMER1MS.
> +	 *
> +	 * Configure CAP_SSS (support stagered spin up).
> +	 * Implement the port0.
> +	 * Get the ahb clock rate, and configure the TIMER1MS register.
> +	 */
> +	ret = readl(mmio + HOST_CAP);

You should use a u32 type for storing readl results.

> +	if (!(ret & HOST_CAP_SSS))
> +		writel(ret |= HOST_CAP_SSS, mmio + HOST_CAP);

Why do you write this conditionally? Just write it unconditionally.

> +	ret = readl(mmio + HOST_PORTS_IMPL);
> +	if (!(ret & 0x1))
> +		writel((ret | 0x1), mmio + HOST_PORTS_IMPL);

ditto.

> +
> +	ahb_clk = devm_clk_get(dev, "ahb");
> +	if (IS_ERR(ahb_clk)) {
> +		dev_err(dev, "no ahb clock.\n");
> +		return PTR_ERR(ahb_clk);
> +	}

This leaves the phy clock enabled in the error case.

> +	ret = clk_get_rate(ahb_clk) / 1000;
> +	writel(ret, mmio + HOST_TIMER1MS);
> +	devm_clk_put(dev, ahb_clk);
> +
> +	return 0;
> +}
> +
> +static void imx6q_sata_exit(struct device *dev)
> +{
> +	struct regmap *gpr;
> +
> +	gpr = syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr");
> +	if (IS_ERR(gpr))
> +		dev_err(dev, "failed to find fsl,imx6q-iomux-gpr regmap\n");
> +
> +	regmap_update_bits(gpr, 0x34, IMX6Q_GPR13_SATA_MPLL_CLK_EN,
> +			!IMX6Q_GPR13_SATA_MPLL_CLK_EN);
> +
> +	imx6q_sata_phy_clk(dev, false);
> +}
> +
> +static struct ahci_platform_data imx6q_sata_pdata = {
> +	.init = imx6q_sata_init,
> +	.exit = imx6q_sata_exit,
> +};
> +static const struct of_device_id imx_ahci_of_match[] = {
> +	{ .compatible = "fsl,imx6q-ahci", .data = &imx6q_sata_pdata},
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, imx_ahci_of_match);
> +
> +static void imx_ahci_platform_release(struct device *dev)
> +{
> +	return;
> +}
> +
> +static struct platform_device ahci_pdev = {
> +	.name = "ahci",
> +	.id = -1,
> +	.dev = {
> +		.release = imx_ahci_platform_release,
> +	}
> +};
> +
> +static int imx_ahci_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct resource *mem, *irq, **res;
> +	const struct of_device_id *of_id;
> +	const struct ahci_platform_data *pdata = NULL;
> +	int ret;
> +
> +	of_id = of_match_device(imx_ahci_of_match, &pdev->dev);
> +	if (of_id)
> +		pdata = of_id->data;
> +	else
> +		return -EINVAL;
> +
> +	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
> +	if (!mem || !irq) {
> +		dev_err(dev, "no mmio/irq resource\n");
> +		return -EINVAL;
> +	}
> +
> +	ahci_pdev.dev.coherent_dma_mask = DMA_BIT_MASK(32);
> +	ahci_pdev.dev.dma_mask = &ahci_pdev.dev.coherent_dma_mask;
> +	ahci_pdev.dev.of_node = pdev->dev.of_node;

No need to make ahci_pdev global. platform_device_add_data makes a copy
anyway and making it global makes this driver broken for multiple
instances.

> +
> +	res[0] = mem;
> +	res[1] = irq;

You have an uninitalized pointer to a pointer to struct resource which
you treat as an array here. Doesn't the compiler warn you?

> +	platform_device_add_resources(&ahci_pdev, *res, 2);
> +	platform_device_add_data(&ahci_pdev, pdata, sizeof(*pdata));
> +
> +	ret = platform_device_register(&ahci_pdev);
> +	if (!ret)
> +		return ret;

s/!ret/ret/

Sascha

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[v3 3/3] sata: imx: add ahci sata support on imx platforms

[Zhu Richard-R65037]

Hi Sascha:
Thanks for your comments.

Best Regards
Richard Zhu
________________________________________
From: Sascha Hauer [s.hauer at pengutronix.de]
Sent: Friday, July 05, 2013 11:59 PM
To: Richard Zhu
Cc: shawn.guo at linaro.org; linux-arm-kernel at lists.infradead.org; jgarzik at pobox.com; avorontsov at ru.mvista.com; rob.herring at calxeda.com; linux-ide at vger.kernel.org; Zhu Richard-R65037
Subject: Re: [v3 3/3] sata: imx: add ahci sata support on imx platforms

On Fri, Jul 05, 2013 at 05:52:22PM +0800, Richard Zhu wrote:
> From: Richard Zhu <r65037@freescale.com>
>
> imx6q contains one Synopsys AHCI SATA controller,
> But it can't shares ahci_platform driver with other
> controllers.
> Because there are some misalignments of the bits
> definitions of the HBA registers and the Vendor
> Specific registers
>  - CAP_SSS(bit20) of the HOST_CAP is writable, default
>  value is '0', should be configured to be '1'
>  - bit0 (only one AHCI SATA port on imx6q) of the
>  HOST_PORTS_IMPL should be set to be '1'.(default 0)
>  - One Vendor Specific register HOST_TIMER1MS(offset:0xe0)
>  should be configured regarding to the frequency of AHB
>  bus clock.
>  - Configurations of the AHCI PHY clock, and the signal
>  parameters of the GPR13
>
> Setup its own ahci sata driver, enable the imx6q ahci
> sata support.
>
> Signed-off-by: Richard Zhu <r65037@freescale.com>
> ---
>  drivers/ata/Kconfig    |    9 ++
>  drivers/ata/Makefile   |    1 +
>  drivers/ata/sata_imx.c |  230 ++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 240 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/ata/sata_imx.c
>
> diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig
> index a5a3ebc..45ed2f0 100644
> --- a/drivers/ata/Kconfig
> +++ b/drivers/ata/Kconfig
> @@ -97,6 +97,15 @@ config SATA_AHCI_PLATFORM
>
>         If unsure, say N.
>
> +config SATA_IMX
> +     tristate "Freescale iMX AHCI SATA support"

It's rather untypical to write iMX. Please write i.MX.
[Richard] Accepted.

> +     depends on SATA_AHCI_PLATFORM
> +     help
> +       This option enables support for the Freescale iMX SoC's
> +       onboard AHCI SATA.
> +
> +       If unsure, say N.
> +
>  config SATA_FSL
>       tristate "Freescale 3.0Gbps SATA support"
>       depends on FSL_SOC
> diff --git a/drivers/ata/Makefile b/drivers/ata/Makefile
> index c04d0fd..04b1c6c 100644
> --- a/drivers/ata/Makefile
> +++ b/drivers/ata/Makefile
> @@ -10,6 +10,7 @@ obj-$(CONFIG_SATA_INIC162X) += sata_inic162x.o
>  obj-$(CONFIG_SATA_SIL24)     += sata_sil24.o
>  obj-$(CONFIG_SATA_DWC)               += sata_dwc_460ex.o
>  obj-$(CONFIG_SATA_HIGHBANK)  += sata_highbank.o libahci.o
> +obj-$(CONFIG_SATA_IMX)               += sata_imx.o
>
>  # SFF w/ custom DMA
>  obj-$(CONFIG_PDC_ADMA)               += pdc_adma.o
> diff --git a/drivers/ata/sata_imx.c b/drivers/ata/sata_imx.c
> new file mode 100644
> index 0000000..a129efb
> --- /dev/null
> +++ b/drivers/ata/sata_imx.c
> @@ -0,0 +1,230 @@
> +/*
> + * Freescale IMX AHCI SATA platform driver
> + * Copyright 2013 Freescale Semiconductor, Inc.
> + *
> + * based on the AHCI SATA platform driver by Jeff Garzik and Anton Vorontsov
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program. If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/kernel.h>
> +#include <linux/gfp.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/device.h>
> +#include <linux/platform_device.h>
> +#include <linux/libata.h>
> +#include <linux/ahci_platform.h>
> +#include <linux/of_device.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
> +#include "ahci.h"
> +#include <linux/clk-private.h>

Do you need anything from clk-private.h? You shouldn't.
[Richard]it would be removed.

> +
> +enum {
> +     HOST_TIMER1MS = 0xe0, /* Timer 1-ms */
> +};
> +
> +/* imx6q ahci module initialization. */
> +static int imx6q_sata_phy_clk(struct device *dev, int enable)
> +{
> +     int ret = 0;
> +     struct clk *sata_ref_clk;
> +
> +     sata_ref_clk = devm_clk_get(dev, "sata_ref_100m");
> +     if (IS_ERR(sata_ref_clk)) {
> +             dev_err(dev, "can't get sata_ref clock.\n");
> +             return PTR_ERR(sata_ref_clk);
> +     }

clk_get must be balanced with clk_put. You need to have some private
data and keep a pointer to the clock.
[Richard] Ok, I can create the private data, and keep a pointer to this clock.

> +     if (enable) {
> +             /* Enable PHY clock */
> +             ret = clk_prepare_enable(sata_ref_clk);
> +             if (ret < 0)
> +                     dev_err(dev, "can't prepare-enable sata_ref clock\n");

When printing error messages it's always helpful to print the error code
aswell.
[Richard] Ok, the return-err code would be added.

> +     } else {
> +             /* Disable PHY clock */

This comment (also the one above enable) doesn't contain any useful
information.
[Richard] ok, they would be removed.

> +             clk_disable_unprepare(sata_ref_clk);
> +     }
> +
> +     return ret;
> +}
> +
> +static int imx6q_sata_init(struct device *dev, void __iomem *mmio)
> +{
> +     int ret = 0;
> +     struct regmap *gpr;
> +     struct clk *ahb_clk;
> +
> +     ret = imx6q_sata_phy_clk(dev, true);
> +     if (ret < 0)
> +             return ret;
> +
> +     gpr = syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr");
> +     if (IS_ERR(gpr)) {
> +             dev_err(dev, "failed to find fsl,imx6q-iomux-gpr regmap\n");
> +             return PTR_ERR(gpr);
> +     }
> +
> +     /*
> +      * set PHY Paremeters, two steps to configure the GPR13,
> +      * one write for rest of parameters, mask of first write
> +      * is 0x07fffffd, and the other one write for setting
> +      * the mpll_clk_en.
> +      */
> +     regmap_update_bits(gpr, 0x34, IMX6Q_GPR13_SATA_RX_EQ_VAL_MASK
> +                     | IMX6Q_GPR13_SATA_RX_LOS_LVL_MASK
> +                     | IMX6Q_GPR13_SATA_RX_DPLL_MODE_MASK
> +                     | IMX6Q_GPR13_SATA_SPD_MODE_MASK
> +                     | IMX6Q_GPR13_SATA_MPLL_SS_EN
> +                     | IMX6Q_GPR13_SATA_TX_ATTEN_MASK
> +                     | IMX6Q_GPR13_SATA_TX_BOOST_MASK
> +                     | IMX6Q_GPR13_SATA_TX_LVL_MASK
> +                     | IMX6Q_GPR13_SATA_TX_EDGE_RATE
> +                     , IMX6Q_GPR13_SATA_RX_EQ_VAL_3_0_DB
> +                     | IMX6Q_GPR13_SATA_RX_LOS_LVL_SATA2M
> +                     | IMX6Q_GPR13_SATA_RX_DPLL_MODE_2P_4F
> +                     | IMX6Q_GPR13_SATA_SPD_MODE_3P0G
> +                     | IMX6Q_GPR13_SATA_MPLL_SS_EN
> +                     | IMX6Q_GPR13_SATA_TX_ATTEN_9_16
> +                     | IMX6Q_GPR13_SATA_TX_BOOST_3_33_DB
> +                     | IMX6Q_GPR13_SATA_TX_LVL_1_025_V);
> +     regmap_update_bits(gpr, 0x34, IMX6Q_GPR13_SATA_MPLL_CLK_EN,
> +                     IMX6Q_GPR13_SATA_MPLL_CLK_EN);
> +     usleep_range(100, 200);
> +
> +     /*
> +      * Configure the HWINIT bits of the HOST_CAP and HOST_PORTS_IMPL,
> +      * and IP vendor specific register HOST_TIMER1MS.
> +      *
> +      * Configure CAP_SSS (support stagered spin up).
> +      * Implement the port0.
> +      * Get the ahb clock rate, and configure the TIMER1MS register.
> +      */
> +     ret = readl(mmio + HOST_CAP);

You should use a u32 type for storing readl results.
[Richard] Accepted.

> +     if (!(ret & HOST_CAP_SSS))
> +             writel(ret |= HOST_CAP_SSS, mmio + HOST_CAP);

Why do you write this conditionally? Just write it unconditionally.
[Richard]Ok, no problem. Would write it uncontitionally.

> +     ret = readl(mmio + HOST_PORTS_IMPL);
> +     if (!(ret & 0x1))
> +             writel((ret | 0x1), mmio + HOST_PORTS_IMPL);

ditto.

> +
> +     ahb_clk = devm_clk_get(dev, "ahb");
> +     if (IS_ERR(ahb_clk)) {
> +             dev_err(dev, "no ahb clock.\n");
> +             return PTR_ERR(ahb_clk);
> +     }

This leaves the phy clock enabled in the error case.
[Richard] Yes, it is. the phy clock should be disabled.

> +     ret = clk_get_rate(ahb_clk) / 1000;
> +     writel(ret, mmio + HOST_TIMER1MS);
> +     devm_clk_put(dev, ahb_clk);
> +
> +     return 0;
> +}
> +
> +static void imx6q_sata_exit(struct device *dev)
> +{
> +     struct regmap *gpr;
> +
> +     gpr = syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr");
> +     if (IS_ERR(gpr))
> +             dev_err(dev, "failed to find fsl,imx6q-iomux-gpr regmap\n");
> +
> +     regmap_update_bits(gpr, 0x34, IMX6Q_GPR13_SATA_MPLL_CLK_EN,
> +                     !IMX6Q_GPR13_SATA_MPLL_CLK_EN);
> +
> +     imx6q_sata_phy_clk(dev, false);
> +}
> +
> +static struct ahci_platform_data imx6q_sata_pdata = {
> +     .init = imx6q_sata_init,
> +     .exit = imx6q_sata_exit,
> +};
> +static const struct of_device_id imx_ahci_of_match[] = {
> +     { .compatible = "fsl,imx6q-ahci", .data = &imx6q_sata_pdata},
> +     {},
> +};
> +MODULE_DEVICE_TABLE(of, imx_ahci_of_match);
> +
> +static void imx_ahci_platform_release(struct device *dev)
> +{
> +     return;
> +}
> +
> +static struct platform_device ahci_pdev = {
> +     .name = "ahci",
> +     .id = -1,
> +     .dev = {
> +             .release = imx_ahci_platform_release,
> +     }
> +};
> +
> +static int imx_ahci_probe(struct platform_device *pdev)
> +{
> +     struct device *dev = &pdev->dev;
> +     struct resource *mem, *irq, **res;
> +     const struct of_device_id *of_id;
> +     const struct ahci_platform_data *pdata = NULL;
> +     int ret;
> +
> +     of_id = of_match_device(imx_ahci_of_match, &pdev->dev);
> +     if (of_id)
> +             pdata = of_id->data;
> +     else
> +             return -EINVAL;
> +
> +     mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +     irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
> +     if (!mem || !irq) {
> +             dev_err(dev, "no mmio/irq resource\n");
> +             return -EINVAL;
> +     }
> +
> +     ahci_pdev.dev.coherent_dma_mask = DMA_BIT_MASK(32);
> +     ahci_pdev.dev.dma_mask = &ahci_pdev.dev.coherent_dma_mask;
> +     ahci_pdev.dev.of_node = pdev->dev.of_node;

No need to make ahci_pdev global. platform_device_add_data makes a copy
anyway and making it global makes this driver broken for multiple
instances.
[Richard]accepted.

> +
> +     res[0] = mem;
> +     res[1] = irq;

You have an uninitalized pointer to a pointer to struct resource which
you treat as an array here. Doesn't the compiler warn you?
[Richard]Compiler doesn't report the warning message, anyway, I would fix it later.

> +     platform_device_add_resources(&ahci_pdev, *res, 2);
> +     platform_device_add_data(&ahci_pdev, pdata, sizeof(*pdata));
> +
> +     ret = platform_device_register(&ahci_pdev);
> +     if (!ret)
> +             return ret;

s/!ret/ret/
[Richard] Would be fixed.

Sascha

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[v3 3/3] sata: imx: add ahci sata support on imx platforms

[Zhu Richard-R65037]

Hi Alexander:
Thanks for your comments.

Best Regards
Richard Zhu
________________________________________
From: Alexander Shiyan [shc_work at mail.ru]
Sent: Saturday, July 06, 2013 12:06 AM
To: Sascha Hauer
Cc: Richard Zhu; Zhu Richard-R65037; shawn.guo at linaro.org; rob.herring at calxeda.com; linux-ide at vger.kernel.org; avorontsov at ru.mvista.com; jgarzik at pobox.com; linux-arm-kernel at lists.infradead.org
Subject: Re[2]: [v3 3/3] sata: imx: add ahci sata support on imx platforms

> On Fri, Jul 05, 2013 at 05:52:22PM +0800, Richard Zhu wrote:
> > From: Richard Zhu <r65037@freescale.com>
...
> > +   if (!(ret & HOST_CAP_SSS))
> > +           writel(ret |= HOST_CAP_SSS, mmio + HOST_CAP);
>
> Why do you write this conditionally? Just write it unconditionally.

"writel" with assignment is incorrect in any case.
[Richard] would be fixed later.

---

[v3 3/3] sata: imx: add ahci sata support on imx platforms

[Tejun Heo]

Hello,

On Fri, Jul 05, 2013 at 05:52:22PM +0800, Richard Zhu wrote:
>  - CAP_SSS(bit20) of the HOST_CAP is writable, default
>  value is '0', should be configured to be '1'
>  - bit0 (only one AHCI SATA port on imx6q) of the
>  HOST_PORTS_IMPL should be set to be '1'.(default 0)
>  - One Vendor Specific register HOST_TIMER1MS(offset:0xe0)
>  should be configured regarding to the frequency of AHB
>  bus clock.
>  - Configurations of the AHCI PHY clock, and the signal
>  parameters of the GPR13

Can't you just add a platform specific init callback to ahci_platform?
I don't see how these small differences in init sequence justify a
separate driver.

Thanks.

-- 
tejun

[v3 3/3] sata: imx: add ahci sata support on imx platforms

[Zhu Richard-R65037]

Hi Tejun:
Thanks for your comments.

Best Regards
Richard Zhu
________________________________________
From: linux-ide-owner@vger.kernel.org [linux-ide-owner at vger.kernel.org] on behalf of Tejun Heo [tj at kernel.org]
Sent: Saturday, July 06, 2013 1:43 AM
To: Richard Zhu
Cc: shawn.guo at linaro.org; linux-arm-kernel at lists.infradead.org; jgarzik at pobox.com; avorontsov at ru.mvista.com; rob.herring at calxeda.com; s.hauer at pengutronix.de; linux-ide at vger.kernel.org; Zhu Richard-R65037
Subject: Re: [v3 3/3] sata: imx: add ahci sata support on imx platforms

Hello,

On Fri, Jul 05, 2013 at 05:52:22PM +0800, Richard Zhu wrote:
>  - CAP_SSS(bit20) of the HOST_CAP is writable, default
>  value is '0', should be configured to be '1'
>  - bit0 (only one AHCI SATA port on imx6q) of the
>  HOST_PORTS_IMPL should be set to be '1'.(default 0)
>  - One Vendor Specific register HOST_TIMER1MS(offset:0xe0)
>  should be configured regarding to the frequency of AHB
>  bus clock.
>  - Configurations of the AHCI PHY clock, and the signal
>  parameters of the GPR13

Can't you just add a platform specific init callback to ahci_platform?
I don't see how these small differences in init sequence justify a
separate driver.
[Richard] Just like what we dicussed in the previous v1/v2 patch-set.
Shawn has the concerns that the IP speicific codes shouldn't be put in the platform level.
So he suggested that setup a stand-alone driver, contained the imx6q ahci sata specific
codes, and re-use the generic ahci_platform driver as much as possible.
This imx6q standalone ahci sata driver just registers the platform data, and the others would be handled
by ahci_platform driver.

Thanks.

--
tejun
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[v3 3/3] sata: imx: add ahci sata support on imx platforms

[Tejun Heo]

Hello,

On Sat, Jul 06, 2013 at 02:03:30AM +0000, Zhu Richard-R65037 wrote:
> [Richard] Just like what we dicussed in the previous v1/v2
> patch-set.  Shawn has the concerns that the IP speicific codes
> shouldn't be put in the platform level.  So he suggested that setup
> a stand-alone driver, contained the imx6q ahci sata specific codes,
> and re-use the generic ahci_platform driver as much as possible.
> This imx6q standalone ahci sata driver just registers the platform
> data, and the others would be handled by ahci_platform driver.

Oh, I'm not objecting to the ahci specific part not being in platform
code.  I'm wondering whether specific handling for imx6q can be
included into ahci_platform rather than being in its own driver.  It
just seems that there aren't too many differences.  I could be
misreading it so if there are enough differences to warrant a separate
driver, please enlighten me.

Thanks!

-- 
tejun

[v3 3/3] sata: imx: add ahci sata support on imx platforms

[Zhu Richard-R65037]

Hi Tejun:
Re-send this email to you and community.
I'm afraid that you may be missed or don't receive it.

BTW, can you help to pick up the #2 and #3(reviewed and acked by Shawn) of the v7 patch-set of this serial?
Thanks in advance.

2013/7/10 HongXing Zhu <richard.zhuhongxing@gmail.com>

    Hi Tejun:
    There are some differences between generic AHCI controller and imx AHCI controller.

    The bits definitions of the HBA registers, the Vendor
    Specific registers, and the AHCI PHY clock, and the PHY signal adjustment window.

     - CAP_SSS(bit20) of the HOST_CAP is writable, default
     value is '0', should be configured to be '1'
     - bit0 (only one AHCI SATA port on imx6q) of the
     HOST_PORTS_IMPL should be set to be '1'.(default 0)
     - One Vendor Specific register HOST_TIMER1MS(offset:0xe0)
     should be configured regarding to the frequency of AHB
     bus clock.
     - Configurations of the AHCI PHY clock, and the signal
     parameters of the GPR13

    I'm afraid that the generic ahci_platform driver is not a good place to contain
    imx6q ahci specific differences.
    As I know that, the AHCI sata on imx53 doesn't have the PHY signal parameters
    adjustment window, but the AHCI sata on imx6q does has one.

    On imx6q, the standard .port_ops = &ahci_platform_ops, is used, but
    .port_ops       = &ahci_platform_retry_srst_ops, would be required by imx53 AHCI controller.

    We can put all the imx AHCI(imx6q, imx53) specific difference into the sata_imx driver,
    and keep ahci_platform as clean as possible, if the separate sata_imx driver can be created.

    How do you think about that?

    BTW, the version4 patch-set would be sent out  a moment later, any suggests and comments are appreciated.

    Best Regards.


    2013/7/6 Tejun Heo <tj@kernel.org>

        Hello,

        On Sat, Jul 06, 2013 at 02:03:30AM +0000, Zhu Richard-R65037 wrote:
        > [Richard] Just like what we dicussed in the previous v1/v2
        > patch-set.  Shawn has the concerns that the IP speicific codes
        > shouldn't be put in the platform level.  So he suggested that setup
        > a stand-alone driver, contained the imx6q ahci sata specific codes,
        > and re-use the generic ahci_platform driver as much as possible.
        > This imx6q standalone ahci sata driver just registers the platform
        > data, and the others would be handled by ahci_platform driver.

        Oh, I'm not objecting to the ahci specific part not being in platform
        code.  I'm wondering whether specific handling for imx6q can be
        included into ahci_platform rather than being in its own driver.  It
        just seems that there aren't too many differences.  I could be
        misreading it so if there are enough differences to warrant a separate
        driver, please enlighten me.

        Thanks!

        --
        tejun

Best Regards
Richard Zhu


-----Original Message-----
From: Tejun Heo [mailto:htejun at gmail.com] On Behalf Of Tejun Heo
Sent: Saturday, July 06, 2013 10:08 AM
To: Zhu Richard-R65037
Cc: Richard Zhu; shawn.guo at linaro.org; linux-arm-kernel at lists.infradead.org; jgarzik at pobox.com; avorontsov at ru.mvista.com; rob.herring at calxeda.com; s.hauer at pengutronix.de; linux-ide at vger.kernel.org
Subject: Re: [v3 3/3] sata: imx: add ahci sata support on imx platforms

Hello,

On Sat, Jul 06, 2013 at 02:03:30AM +0000, Zhu Richard-R65037 wrote:
> [Richard] Just like what we dicussed in the previous v1/v2 patch-set.  
> Shawn has the concerns that the IP speicific codes shouldn't be put in 
> the platform level.  So he suggested that setup a stand-alone driver, 
> contained the imx6q ahci sata specific codes, and re-use the generic 
> ahci_platform driver as much as possible.
> This imx6q standalone ahci sata driver just registers the platform 
> data, and the others would be handled by ahci_platform driver.

Oh, I'm not objecting to the ahci specific part not being in platform code.  I'm wondering whether specific handling for imx6q can be included into ahci_platform rather than being in its own driver.  It just seems that there aren't too many differences.  I could be misreading it so if there are enough differences to warrant a separate driver, please enlighten me.

Thanks!

--
tejun

[v3 3/3] sata: imx: add ahci sata support on imx platforms

[Tejun Heo]

Hello,

On Mon, Jul 22, 2013 at 07:02:56AM +0000, Zhu Richard-R65037 wrote:
> Re-send this email to you and community.
> I'm afraid that you may be missed or don't receive it.

Sorry about the delay.  I was on the road.

> BTW, can you help to pick up the #2 and #3(reviewed and acked by Shawn) of the v7 patch-set of this serial?
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Just one thing, can you please rename the driver to ahci_imx?  I'd
like to keep all ahci drivers with ahci prefix (yeah, there's already
an exception, I know).

Thanks.

-- 
tejun

[v3 3/3] sata: imx: add ahci sata support on imx platforms

[Zhu Richard-R65037]

Hi Tejun:
Thanks a lot.

No problem, I can rename the driver from sata_imx to ahci_imx.

Best Regards
Richard Zhu


-----Original Message-----
From: Tejun Heo [mailto:htejun at gmail.com] On Behalf Of Tejun Heo
Sent: Wednesday, July 24, 2013 12:26 AM
To: Zhu Richard-R65037
Cc: Richard Zhu; shawn.guo at linaro.org; linux-arm-kernel at lists.infradead.org; jgarzik at pobox.com; avorontsov at ru.mvista.com; rob.herring at calxeda.com; s.hauer at pengutronix.de; linux-ide at vger.kernel.org
Subject: Re: [v3 3/3] sata: imx: add ahci sata support on imx platforms

Hello,

On Mon, Jul 22, 2013 at 07:02:56AM +0000, Zhu Richard-R65037 wrote:
> Re-send this email to you and community.
> I'm afraid that you may be missed or don't receive it.

Sorry about the delay.  I was on the road.

> BTW, can you help to pick up the #2 and #3(reviewed and acked by Shawn) of the v7 patch-set of this serial?
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Just one thing, can you please rename the driver to ahci_imx?  I'd like to keep all ahci drivers with ahci prefix (yeah, there's already an exception, I know).

Thanks.

--
tejun