Re: [PATCH v3] mmc: sdhci-pci: add Support of Synopsys DWC_MSHC IP

From: Jaehoon Chung
Date: Tue Apr 26 2016 - 06:45:48 EST


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 <prabu.t@xxxxxxxxxxxx>
>> ---
>> 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 <prabu.t@xxxxxxxxxxxx>
>> +M: Manjunath M B <manjumb@xxxxxxxxxxxx>
>> +L: linux-mmc@xxxxxxxxxxxxxxx
>> +S: Maintained
>> +F: drivers/mmc/host/sdhci-pci-dwc*
>> +
>> SYSTEM TRACE MODULE CLASS
>> M: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
>> 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 <manjumb@xxxxxxxxxxxx>
>> + *
>> + * 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 <manjumb@xxxxxxxxxxxx>
>> + *
>> + * 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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