On 04/26/2016 05:58 PM, Ludovic Desroches wrote:
> On Wed, Apr 20, 2016 at 12:22:59PM +0000, Prabu Thangamuthu wrote:
>> Patch for Standard SD Host Controller Interface compliant Synopsys
>> sdhci-dwc controller driver. This code supports PCI based interface.
>>
>> Signed-off-by: Prabu Thangamuthu <[email protected]>
>> ---
>> Change log v3:
>>      -Removed unused code.
>>      -Updated review comments.
>>
>> Change log v2:
>>      -Removed Synopsys specific PCI device ID's from pci_ids.h.
>>      -Updated the PCI device ID's in sdhci-pci-core.c.
>>
>>  MAINTAINERS                       |   7 +
>>  drivers/mmc/host/Makefile         |   3 +-
>>  drivers/mmc/host/sdhci-pci-core.c |  14 ++
>>  drivers/mmc/host/sdhci-pci-dwc.c  | 260 
>> ++++++++++++++++++++++++++++++++++++++
>>  drivers/mmc/host/sdhci-pci-dwc.h  |  55 ++++++++
>>  5 files changed, 338 insertions(+), 1 deletion(-)
>>  create mode 100644 drivers/mmc/host/sdhci-pci-dwc.c
>>  create mode 100644 drivers/mmc/host/sdhci-pci-dwc.h
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 1d5b4be..01b40da 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -9751,6 +9751,13 @@ S:    Maintained
>>  F:  include/linux/mmc/dw_mmc.h
>>  F:  drivers/mmc/host/dw_mmc*
>>  
>> +SYNOPSYS SDHCI COMPLIANT DWC MSHC DRIVER
>> +M:  Prabu Thangamuthu <[email protected]>
>> +M:  Manjunath M B <[email protected]>
>> +L:  [email protected]
>> +S:  Maintained
>> +F:  drivers/mmc/host/sdhci-pci-dwc*
>> +
>>  SYSTEM TRACE MODULE CLASS
>>  M:  Alexander Shishkin <[email protected]>
>>  S:  Maintained
>> diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
>> index af918d2..092a746 100644
>> --- a/drivers/mmc/host/Makefile
>> +++ b/drivers/mmc/host/Makefile
>> @@ -9,7 +9,8 @@ obj-$(CONFIG_MMC_MXC)                += mxcmmc.o
>>  obj-$(CONFIG_MMC_MXS)               += mxs-mmc.o
>>  obj-$(CONFIG_MMC_SDHCI)             += sdhci.o
>>  obj-$(CONFIG_MMC_SDHCI_PCI) += sdhci-pci.o
>> -sdhci-pci-y                 += sdhci-pci-core.o sdhci-pci-o2micro.o
>> +sdhci-pci-y                 += sdhci-pci-core.o sdhci-pci-o2micro.o \
>> +                               sdhci-pci-dwc.o
>>  obj-$(subst m,y,$(CONFIG_MMC_SDHCI_PCI))    += sdhci-pci-data.o
>>  obj-$(CONFIG_MMC_SDHCI_ACPI)        += sdhci-acpi.o
>>  obj-$(CONFIG_MMC_SDHCI_PXAV3)       += sdhci-pxav3.o
>> diff --git a/drivers/mmc/host/sdhci-pci-core.c 
>> b/drivers/mmc/host/sdhci-pci-core.c
>> index 79e1901..4a7769c 100644
>> --- a/drivers/mmc/host/sdhci-pci-core.c
>> +++ b/drivers/mmc/host/sdhci-pci-core.c
>> @@ -31,6 +31,7 @@
>>  #include "sdhci.h"
>>  #include "sdhci-pci.h"
>>  #include "sdhci-pci-o2micro.h"
>> +#include "sdhci-pci-dwc.h"
>>  
>>  
>> /*****************************************************************************\
>>   *                                                                          
>>  *
>> @@ -70,6 +71,11 @@ static int ricoh_mmc_resume(struct sdhci_pci_chip *chip)
>>      msleep(500);
>>      return 0;
>>  }
>> +/* Synopsys SDHCI compliant Controller */
>> +static const struct sdhci_pci_fixes sdhci_snps = {
>> +    .probe_slot     = sdhci_pci_probe_slot_snps,
>> +    .quirks2        = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
>> +};
>>  
>>  static const struct sdhci_pci_fixes sdhci_ricoh = {
>>      .probe          = ricoh_probe,
>> @@ -797,6 +803,14 @@ static const struct sdhci_pci_fixes sdhci_amd = {
>>  
>>  static const struct pci_device_id pci_ids[] = {
>>      {
>> +            .vendor         = PCI_VENDOR_ID_SYNOPSYS,
>> +            .device         = 0xc201, /* Device ID of sdhci-dwc on Haps51 */
>> +            .subvendor      = PCI_ANY_ID,
>> +            .subdevice      = PCI_ANY_ID,
>> +            .driver_data    = (kernel_ulong_t)&sdhci_snps,
>> +    },
>> +
>> +    {
>>              .vendor         = PCI_VENDOR_ID_RICOH,
>>              .device         = PCI_DEVICE_ID_RICOH_R5C822,
>>              .subvendor      = PCI_ANY_ID,
>> diff --git a/drivers/mmc/host/sdhci-pci-dwc.c 
>> b/drivers/mmc/host/sdhci-pci-dwc.c
>> new file mode 100644
>> index 0000000..3490af8
>> --- /dev/null
>> +++ b/drivers/mmc/host/sdhci-pci-dwc.c
>> @@ -0,0 +1,260 @@
>> +/*
>> + * Copyright (C) 2016 Synopsys, Inc.
>> + *
>> + * Author: Manjunath M B <[email protected]>
>> + *
>> + * This software is licensed under the terms of the GNU General Public
>> + * License version 2, as published by the Free Software Foundation, and
>> + * may be copied, distributed, and modified under those terms.
>> + *
>> + * This program is distributed in the hope that 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.
>> + *
>> + */
>> +
>> +#include <linux/pci.h>
>> +#include <linux/delay.h>
>> +#include <linux/module.h>
>> +#include <linux/moduleparam.h>
>> +
>> +#include "sdhci.h"
>> +#include "sdhci-pci.h"
>> +#include "sdhci-pci-dwc.h"
>> +
>> +/*****************************************************************************\
>> + *                                                                          
>>  *
>> + * Hardware specific clock handling                                         
>>  *
>> + *                                                                          
>>  *
>> +\*****************************************************************************/
>> +static const struct sdhci_ops *sdhci_ops;   /* Low level hw interface */
>> +
>> +static void snps_reset_dcm(struct sdhci_host *host,
>> +                            unsigned int mask, unsigned char reset)

unsigned int/unsigned char -> u32/u8 ?


>> +{
>> +    u32 reg = 0;
>> +    u16 vendor_ptr = 0;
> 
> These variables can't be used uninitialized so no need to initialize
> them.
> 
>> +
>> +    vendor_ptr = sdhci_readw(host, SDHCI_UHS2_VENDOR);
>> +
>> +    reg = sdhci_readl(host, (SDHC_GPIO_OUT + vendor_ptr));
>> +
>> +    if (reset == 1)
>> +            reg |= mask;
>> +    else
>> +            reg &= ~mask;
>> +
>> +    sdhci_writel(host, reg, (SDHC_GPIO_OUT + vendor_ptr));
>> +}
>> +
>> +static void sdhci_set_clock_snps(struct sdhci_host *host,
>> +                                            unsigned int clock)
>> +{
>> +    int div = 0;
>> +    int mul = 0;
>> +    int div_val = 0;
>> +    int mul_val = 0;
>> +    int mul_div_val = 0;
>> +    u32 reg = 0;
>> +    u16 clk = 0;
>> +    u16 vendor_ptr = 0;
>> +    u32 mask = 0;
>> +    unsigned long timeout;
>> +    u32 tx_clk_phase_val = SDHC_DEF_TX_CLK_PH_VAL;
>> +    u32 rx_clk_phase_val = SDHC_DEF_RX_CLK_PH_VAL;
>> +
> 
> Some variables don't need to be initialized here.

tx/rx_clk_phase_val don't need?
i didn't see any modifying these vales.

And some variables don't need to define..can be reused.

> 
>> +    /*
>> +     * if clock is less than 25MHz, divided clock is used.
>> +     * For divided clock, we can use the standard sdhci_set_clock().
>> +     * For clock above 25MHz, DRP clock is used
>> +     * Here, we cannot use sdhci_set_clock(), we need to program
>> +     * TX RX CLOCK DCM DRP for appropriate clock
>> +     */
>> +
>> +    if (clock <= 25000000) {
>> +            /* Then call generic set_clock */
>> +            if (sdhci_ops->set_clock)
>> +                    sdhci_ops->set_clock(host, clock);
> 
> I am not sure about this part. You may simply call sdhci_set_clock() instead 
> of
> sdhci_ops->set_clock(). See my latest comment, it is not clear what is
> behind set_clock().
> 
>> +    } else {
>> +
>> +            host->mmc->actual_clock = 0;
>> +            vendor_ptr = sdhci_readw(host, SDHCI_UHS2_VENDOR);
>> +
>> +            /* Select un-phase shifted clock before reset Tx Tuning DCM*/
>> +            reg = sdhci_readl(host, (SDHC_GPIO_OUT + vendor_ptr));
>> +            reg &= ~SDHC_TX_CLK_SEL_TUNED;
>> +            sdhci_writel(host, reg, (SDHC_GPIO_OUT + vendor_ptr));
>> +            mdelay(10);
>> +
>> +            sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
>> +
>> +            /* Lets chose the Mulitplier value to be 0x2 */
>> +            mul = 0x2;
>> +            for (div = 1; div <= 32; div++) {
>> +                    if (((host->max_clk * mul) / div)
>> +                                    <= clock)
>> +                            break;
>> +            }
>> +            /*
>> +             * Set Programmable Clock Mode in the Clock
>> +             * Control register.
>> +             */
>> +            div_val = div - 1;
>> +            mul_val = mul - 1;
>> +
>> +            host->mmc->actual_clock = (host->max_clk * mul) / div;
>> +            /*
>> +             * Program the DCM DRP
>> +             * Step 1: Assert DCM Reset
>> +             * Step 2: Program the mul and div values in DRP
>> +             * Step 3: Read from DRP base 0x00 to restore DCM output as per
>> +             * www.xilinx.com/support/documentation/user_guides/ug191.pdf
>> +             * Step 4: De-Assert reset to DCM
>> +             */
>> +
>> +            mask = SDHC_CARD_TX_CLK_DCM_RST;
>> +            snps_reset_dcm(host, mask, 1);
>> +
>> +            mul_div_val = (mul_val << 8) | div_val;
>> +            sdhci_writew(host, mul_div_val, TXRX_CLK_DCM_MUL_DIV_DRP);
>> +
>> +            reg = sdhci_readl(host, TXRX_CLK_DCM_DRP_BASE_51);
>> +
>> +            snps_reset_dcm(host, mask, 0);
>> +
>> +            clk |= SDHCI_PROG_CLOCK_MODE | SDHCI_CLOCK_INT_EN;
>> +            sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
>> +
>> +            /* Wait max 20 ms */
>> +            timeout = 20;
>> +            while (!((clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL))
>> +                                    & SDHCI_CLOCK_INT_STABLE)) {
>> +                    if (timeout == 0) {
>> +                            pr_err("%s: Internal clock never stabilised\n",
>> +                                            mmc_hostname(host->mmc));
>> +                            return;
>> +                    }
>> +                    timeout--;
>> +                    mdelay(1);
>> +            }
>> +
>> +            clk |= SDHCI_CLOCK_CARD_EN;
>> +            sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
>> +
>> +            /*
>> +             * This Clock might have affected the TX CLOCK DCM and RX CLOCK
>> +             * DCM which are used for Phase control; Reset these DCM's
>> +             * for proper clock output
>> +             *
>> +             * Step 1: Reset the DCM
>> +             * Step 2: De-Assert reset to DCM
>> +             */
>> +
>> +            mask = SDHC_TUNING_TX_CLK_DCM_RST | SDHC_TUNING_RX_CLK_DCM_RST;
>> +            snps_reset_dcm(host, mask, 1);
>> +            mdelay(10);
>> +            snps_reset_dcm(host, mask, 0);
>> +
>> +            /* Select working phase value if clock is <= 50MHz */
>> +            if (clock <= 50000000) {
>> +                    /*Change the Tx Phase value here */
>> +                    reg = sdhci_readl(host, (SDHC_GPIO_OUT + vendor_ptr));
>> +                    reg |= (SDHC_TUNING_TX_CLK_SEL_MASK &
>> +                       (tx_clk_phase_val << SDHC_TUNING_TX_CLK_SEL_SHIFT));
>> +
>> +                    sdhci_writel(host, reg, (SDHC_GPIO_OUT + vendor_ptr));
>> +                    mdelay(10);
>> +
>> +                    /* Program to select phase shifted clock */
>> +                    reg |= SDHC_TX_CLK_SEL_TUNED;
>> +                    sdhci_writel(host, reg, (SDHC_GPIO_OUT + vendor_ptr));
>> +
>> +                    /*
>> +                     * For 50Mhz, tuning is not possible.
>> +                     * Lets fix the sampling Phase of Rx Clock here.
>> +                     */
>> +                    reg = sdhci_readl(host, (SDHC_DBOUNCE + vendor_ptr));
>> +                    reg &= ~SDHC_TUNING_RX_CLK_SEL_MASK;
>> +                    reg |= (SDHC_TUNING_RX_CLK_SEL_MASK &
>> +                                    rx_clk_phase_val);
>> +                    sdhci_writel(host, reg, (SDHC_DBOUNCE + vendor_ptr));
>> +            }
>> +            mdelay(10);
>> +    }
>> +}
>> +
>> +static int snps_init_clock(struct sdhci_host *host)
>> +{
>> +    int div = 0;
>> +    int mul = 0;
>> +    int div_val = 0;
>> +    int mul_val = 0;
>> +    int mul_div_val = 0;
>> +    int reg = 0;
>> +    u32 mask = 0;
>> +
> 
> Some variables don't need initialization here or you can directly assign
> the right value: int div = 2, mul = 2, etc.

I think div/mul variables don't need to define, right?
and mul_val and div_val also don't need.

Finally, mul,div didn't need..just use mul_val and div_val are 1?
It seems that mul_val and div_val are already fixed. (just 1)

> 
>> +    /* Configure the BCLK DRP to get 100 MHZ Clock */

Combine with the below comment.

>> +
>> +    /*
>> +     * To get 100MHz from 100MHz input freq,
>> +     * mul=2 and div=2
>> +     * Formula: output_clock = (input clock * mul) / div
>> +     */
>> +    mul = 2;
>> +    div = 2;
>> +    mul_val = mul - 1;
>> +    div_val = div - 1;
>> +    /*
>> +     * Program the DCM DRP
>> +     * Step 1: Assert DCM Reset
>> +     * Step 2: Program the mul and div values in DRP
>> +     * Step 3: Read from DRP base 0x00 to restore DCM output as per
>> +     * www.xilinx.com/support/documentation/user_guides/ug191.pdf
>> +     * Step 4: De-Assert reset to DCM
>> +     */
>> +    mask = SDHC_BCLK_DCM_RST;
>> +    snps_reset_dcm(host, mask, 1);

snps_reset_dcm(host, SDHC_BCLK_DCM_RST, 1);

>> +
>> +    mul_div_val = (mul_val << 8) | div_val;


mul_div_val is also fixed?

mul_val = 1, div_val = 1..then mul_div_val is 0x101?


>> +    sdhci_writew(host, mul_div_val, BCLK_DCM_MUL_DIV_DRP);
>> +
>> +    reg = sdhci_readl(host, BCLK_DCM_DRP_BASE_51);

just read? then
        sdhci_readl(host, BCLK_DCM_DRP_BASE_51);?

If my comments are right, you can remove above parameters.
(div, mul, div_val, mul_val, mul_div_val, reg, mask..all)

Best Regards,
Jaehoon Chung

>> +
>> +    snps_reset_dcm(host, mask, 0);
>> +
>> +    /*
>> +     * By Default Clocks to Controller are OFF.
>> +     * Before stack applies reset; we need to turn on the clock
>> +     */
>> +    sdhci_writew(host, SDHCI_CLOCK_INT_EN, SDHCI_CLOCK_CONTROL);
>> +
>> +    return 0;
>> +
>> +}
>> +static struct sdhci_ops sdhci_pci_ops_snps = {
>> +    .set_clock      = sdhci_set_clock_snps,
>> +};
>> +
>> +int sdhci_pci_probe_slot_snps(struct sdhci_pci_slot *slot)
>> +{
>> +    int ret = 0;
>> +    struct sdhci_host *host;
>> +
>> +    host = slot->host;
>> +    sdhci_ops = host->ops;
>> +
>> +    sdhci_pci_ops_snps.enable_dma           = sdhci_ops->enable_dma;
>> +    sdhci_pci_ops_snps.set_bus_width        = sdhci_ops->set_bus_width;
>> +    sdhci_pci_ops_snps.reset                = sdhci_ops->reset;
>> +    sdhci_pci_ops_snps.set_uhs_signaling    = sdhci_ops->set_uhs_signaling;
>> +    sdhci_pci_ops_snps.hw_reset             = sdhci_ops->hw_reset;
>> +
>> +    host->ops = &sdhci_pci_ops_snps;
> 
> I am lost. sdhci_ops is a kind of backup of the original ops from
> pci core. Your sdhci_pci_ops_snps is a copy of ops from pci core
> excepting set_clock and finally you update pci core ops with
> sdhci_pci_ops_snps.
> 
> It seems a bit complex. At the end, unless I have missed something, you
> have only changed set_clock from pci ops.
> 
> 
> Regards
> 
> Ludovic
> 
>> +
>> +    /* Board specific clock initialization */
>> +    ret = snps_init_clock(host);
>> +
>> +    return ret;
>> +}
>> +EXPORT_SYMBOL_GPL(sdhci_pci_probe_slot_snps);
>> diff --git a/drivers/mmc/host/sdhci-pci-dwc.h 
>> b/drivers/mmc/host/sdhci-pci-dwc.h
>> new file mode 100644
>> index 0000000..02e2213
>> --- /dev/null
>> +++ b/drivers/mmc/host/sdhci-pci-dwc.h
>> @@ -0,0 +1,55 @@
>> +/*
>> + * Copyright (C) 2016 Synopsys, Inc.
>> + *
>> + * Author: Manjunath M B <[email protected]>
>> + *
>> + * This software is licensed under the terms of the GNU General Public
>> + * License version 2, as published by the Free Software Foundation, and
>> + * may be copied, distributed, and modified under those terms.
>> + *
>> + * This program is distributed in the hope that 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.
>> + *
>> + */
>> +
>> +#ifndef __SDHCI_DWC_MSHC_PCI_H__
>> +#define __SDHCI_DWC_MSHC_PCI_H__
>> +
>> +#include "sdhci-pci.h"
>> +
>> +#define SDHCI_UHS2_VENDOR   0xE8
>> +
>> +#define DRIVER_NAME "sdhci-pci-dwc"
>> +#define SDHC_DEF_TX_CLK_PH_VAL  4
>> +#define SDHC_DEF_RX_CLK_PH_VAL  4
>> +
>> +/* Synopsys Vendor Specific Registers */
>> +#define SDHC_DBOUNCE                           0x08
>> +#define SDHC_TUNING_RX_CLK_SEL_MASK            0x000000FF
>> +#define SDHC_GPIO_OUT                          0x34
>> +/* HAPS 51 Based implementation */
>> +#define SDHC_BCLK_DCM_RST                      0x00000001
>> +#define SDHC_CARD_TX_CLK_DCM_RST               0x00000002
>> +#define SDHC_TUNING_RX_CLK_DCM_RST             0x00000004
>> +#define SDHC_TUNING_TX_CLK_DCM_RST             0x00000008
>> +#define SDHC_TUNING_TX_CLK_SEL_MASK            0x00000070
>> +#define SDHC_TUNING_TX_CLK_SEL_SHIFT           4
>> +#define SDHC_TX_CLK_SEL_TUNED                  0x00000080
>> +
>> +/* Offset of BCLK DCM DRP Attributes */
>> +/* Every attribute is of 16 bit wide */
>> +#define BCLK_DCM_DRP_BASE_51                   0x1000
>> +
>> +#define BCLK_DCM_MUL_DIV_DRP                   0x1050
>> +#define MUL_MASK_DRP                           0xFF00
>> +#define DIV_MASK_DRP                           0x00FF
>> +
>> +/* Offset of TX and RX CLK DCM DRP */
>> +#define TXRX_CLK_DCM_DRP_BASE_51               0x2000
>> +#define TXRX_CLK_DCM_MUL_DIV_DRP               0x2050
>> +
>> +int sdhci_pci_probe_slot_snps(struct sdhci_pci_slot *slot);
>> +
>> +#endif
>> -- 
>> 1.9.1
>>
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