Re: [PATCH v2 2/5] mmc: zx: Initial support for ZX mmc controller

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2016-10-31 17:40 GMT+08:00 Jaehoon Chung <jh80.chung@xxxxxxxxxxx>:
> On 10/31/2016 05:47 PM, Jun Nie wrote:
>> 2016-10-28 13:16 GMT+08:00 Jaehoon Chung <jh80.chung@xxxxxxxxxxx>:
>>> On 10/28/2016 11:37 AM, Jun Nie wrote:
>>>> This platform driver adds initial support for the DW host controller
>>>> found on ZTE SoCs.
>>>>
>>>> It has been tested on ZX296718 EVB board currently. More support on
>>>> timing tuning will be added when hardware is available.
>>>>
>>>> Signed-off-by: Jun Nie <jun.nie@xxxxxxxxxx>
>>>> ---
>>>>  drivers/mmc/host/Kconfig     |   9 ++
>>>>  drivers/mmc/host/Makefile    |   1 +
>>>>  drivers/mmc/host/dw_mmc-zx.c | 230 +++++++++++++++++++++++++++++++++++++++++++
>>>>  drivers/mmc/host/dw_mmc-zx.h |  23 +++++
>>>>  4 files changed, 263 insertions(+)
>>>>  create mode 100644 drivers/mmc/host/dw_mmc-zx.c
>>>>  create mode 100644 drivers/mmc/host/dw_mmc-zx.h
>>>>
>>>> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
>>>> index 5274f50..2b3202c 100644
>>>> --- a/drivers/mmc/host/Kconfig
>>>> +++ b/drivers/mmc/host/Kconfig
>>>> @@ -662,6 +662,15 @@ config MMC_DW_ROCKCHIP
>>>>         Synopsys DesignWare Memory Card Interface driver. Select this option
>>>>         for platforms based on RK3066, RK3188 and RK3288 SoC's.
>>>>
>>>> +config MMC_DW_ZX
>>>> +     tristate "ZTE specific extensions for Synopsys DW Memory Card Interface"
>>>> +     depends on MMC_DW
>>>
>>> I guess MMC_DW_ZX depends on your SoC config, doesn't?
>>
>> Right, will add dependency.
>>
>>>
>>>> +     select MMC_DW_PLTFM
>>>> +     help
>>>> +       This selects support for ZTE SoC specific extensions to the
>>>> +       Synopsys DesignWare Memory Card Interface driver. Select this option
>>>> +       for platforms based on ZX296718 SoC's.
>>>> +
>>>>  config MMC_SH_MMCIF
>>>>       tristate "SuperH Internal MMCIF support"
>>>>       depends on HAS_DMA
>>>> diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
>>>> index e2bdaaf..9766143 100644
>>>> --- a/drivers/mmc/host/Makefile
>>>> +++ b/drivers/mmc/host/Makefile
>>>> @@ -48,6 +48,7 @@ obj-$(CONFIG_MMC_DW_EXYNOS) += dw_mmc-exynos.o
>>>>  obj-$(CONFIG_MMC_DW_K3)              += dw_mmc-k3.o
>>>>  obj-$(CONFIG_MMC_DW_PCI)     += dw_mmc-pci.o
>>>>  obj-$(CONFIG_MMC_DW_ROCKCHIP)        += dw_mmc-rockchip.o
>>>> +obj-$(CONFIG_MMC_DW_ZX)              += dw_mmc-zx.o
>>>>  obj-$(CONFIG_MMC_SH_MMCIF)   += sh_mmcif.o
>>>>  obj-$(CONFIG_MMC_JZ4740)     += jz4740_mmc.o
>>>>  obj-$(CONFIG_MMC_VUB300)     += vub300.o
>>>> diff --git a/drivers/mmc/host/dw_mmc-zx.c b/drivers/mmc/host/dw_mmc-zx.c
>>>> new file mode 100644
>>>> index 0000000..0404f8e
>>>> --- /dev/null
>>>> +++ b/drivers/mmc/host/dw_mmc-zx.c
>>>> @@ -0,0 +1,230 @@
>>>> +/*
>>>> + * ZX Specific Extensions for Synopsys DW Multimedia Card Interface driver
>>>> + *
>>>> + * Copyright (C) 2016, Linaro Ltd.
>>>> + * Copyright (C) 2016, ZTE Corp.
>>>> + *
>>>> + * 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/mfd/syscon.h>
>>>> +#include <linux/mmc/dw_mmc.h>
>>>> +#include <linux/mmc/host.h>
>>>> +#include <linux/mmc/mmc.h>
>>>> +#include <linux/module.h>
>>>> +#include <linux/of.h>
>>>> +#include <linux/platform_device.h>
>>>> +#include <linux/pm_runtime.h>
>>>> +#include <linux/regmap.h>
>>>> +#include <linux/slab.h>
>>>> +
>>>> +#include "dw_mmc.h"
>>>> +#include "dw_mmc-pltfm.h"
>>>> +#include "dw_mmc-zx.h"
>>>> +
>>>> +#define ZX_DLL_LOCKED BIT(2)
>>>
>>> Some DLL rigsters and bits are defined in dw_mmc-zx.h.
>>> why defined ZX_DLL_LOCKED at here.
>>>
>>> You can choose that all defines locates to dw_mmc-zx.c or dw_mmc-zx.h
>>>
>> Will move together.
>>
>>>> +
>>>> +struct dw_mci_zx_priv_data {
>>>> +     struct regmap   *sysc_base;
>>>> +};
>>>> +
>>>> +static int dw_mci_zx_emmc_set_delay(struct dw_mci *host, unsigned int delay,
>>>> +                                 unsigned int clk_flag)
>>>
>>> Why do you use "unsigned int" as clk_flag? It's just use one of 0 and 1.
>>> And 0 and 1 are what means? On/Off?
>>>
>> Yes,  enumeration shall looks better here. It is a flag for different
>> delay type. Will change to enumeration.
>>
>>>> +{
>>>> +     struct dw_mci_zx_priv_data *priv = host->priv;
>>>> +     struct regmap *sysc_base = priv->sysc_base;
>>>> +     unsigned int clksel;
>>>> +     unsigned int loop = 1000;
>>>> +     int ret;
>>>> +
>>>
>>> priv->sysc_base doesn't never NULL?
>>
>> For this SoC, it is never NULL if dts is correct. Adding a check is
>> better anyway.
>>>
>>>> +     ret = regmap_write(sysc_base, LB_AON_EMMC_CFG_REG0,
>>>> +                        PARA_DLL_START_POINT(4) | PARA_DLL_LOCK_NUM(4));
>>>
>>> Could you add the comment for controlling this regs?
>>> I'm not sure because i didn't have ZX TRM..but PARA_DLL_LOCK_NUM should be locked?
>>>
>>> It doesn't affect to other bit?
>>> I think you can use the regmap_update_bits instead of regmap_write.
>>
>> It does not affect other bit as all bits are write as desired. But
>> your suggestion make it clearer.
>>
>>>
>>>> +     if (ret)
>>>> +             return ret;
>>>> +
>>>> +     ret = regmap_read(sysc_base, LB_AON_EMMC_CFG_REG1, &clksel);
>>>> +     if (ret)
>>>> +             return ret;
>>>> +
>>>> +     if (clk_flag) {
>>>> +             clksel &= ~(CLK_SAMP_DELAY(0x7F));
>>>
>>> It's meaningless..CLK_SAMP_DELAY used only at here.
>>> CLK_SAMP_DELAY ((x) & 0x7F << 0)
>>>
>>> It's just CLK_SAMP_DELAY_MASK.?
>>>
>>> #define CLK_SAMP_DELAY_MASK (0x7F << 0)
>>> clksel &= ~CLK_SAMP_DELAY_MASK;
>>>
>> Right, clearer.
>>
>>>
>>>> +             clksel |= (delay << 8);
>>>
>>> Use the CLK_SAMP_DELAY_SHIFT instead of 8.
>>>
>>>> +     } else {
>>>> +             clksel &= ~(READ_DQS_DELAY(0x7F));
>>>
>>> Ditto.
>>> And i think it also can be changed to regmap_update_bits.
>>>
>>>> +             clksel |= delay;
>>>> +     }
>>>> +
>>>> +     regmap_write(sysc_base, LB_AON_EMMC_CFG_REG1, clksel);
>>>> +     regmap_write(sysc_base, LB_AON_EMMC_CFG_REG0,
>>>> +                  PARA_DLL_START_POINT(4) | PARA_DLL_LOCK_NUM(4) |
>>>> +                  DLL_REG_SET);
>>>
>>> regmap_update_bits?
>>
>> Will do.
>>
>>>
>>>> +
>>>> +     do {
>>>> +             ret = regmap_read(sysc_base, LB_AON_EMMC_CFG_REG2, &clksel);
>>>> +             if (ret)
>>>> +                     return ret;
>>>> +
>>>> +     } while (--loop && !(clksel & ZX_DLL_LOCKED));
>>>> +
>>>> +     if (!loop) {
>>>> +             dev_err(host->dev, "Error: %s dll lock fail\n", __func__);
>>>> +             return -EIO;
>>>> +     }
>>>> +
>>>> +     return 0;
>>>> +}
>>>> +
>>>> +static int dw_mci_zx_emmc_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
>>>> +{
>>>> +     struct dw_mci *host = slot->host;
>>>> +     struct mmc_host *mmc = slot->mmc;
>>>> +     int len, start = 0, end = 0, delay, best = 0;
>>>> +     int ret = 0;
>>>> +
>>>> +     for (delay = 1 ; delay < 128; delay++) {
>>>> +             ret = dw_mci_zx_emmc_set_delay(host, delay, 1);
>>>> +             if (ret)
>>>> +                     return ret;
>>>
>>> When it's failed, just returned.
>>> Doesn't need to try with next delay value?
>>
>> Yes, more retry make robust.
>>
>>>
>>>> +
>>>> +             if (mmc_send_tuning(mmc, opcode, NULL)) {
>>>> +                     if (start >= 0) {
>>>> +                             end = delay - 1;
>>>> +                             /* check and update longest good range */
>>>> +                             if ((end - start) > len) {
>>>> +                                     best = (start + end) >> 1;
>>>> +                                     len = end - start;
>>>> +                             }
>>>> +                     }
>>>> +                     start = -1;
>>>> +                     end = 0;
>>>> +                     continue;
>>>> +             }
>>>> +             if (start < 0)
>>>> +                     start = delay;
>>>> +     }
>>>> +
>>>> +     if (start >= 0) {
>>>> +             end = delay - 1;
>>>> +             if ((end - start) > len) {
>>>> +                     best = (start + end) >> 1;
>>>> +                     len = end - start;
>>>> +             }
>>>> +     }
>>>> +     if (best < 0)
>>>> +             return -EIO;
>>>> +
>>>> +     dev_info(host->dev, "%s best range: start %d end %d\n", __func__,
>>>> +              start, end);
>>>> +     dw_mci_zx_emmc_set_delay(host, best, 1);
>>>> +     return 0;
>>>> +}
>>>> +
>>>> +static int dw_mci_zx_prepare_hs400_tuning(struct dw_mci *host,
>>>> +                                       struct mmc_ios *ios)
>>>> +{
>>>> +     int ret;
>>>> +
>>>> +     /* config phase shift 90 */
>>>> +     ret = dw_mci_zx_emmc_set_delay(host, 32, 0);
>>>
>>> It's always fixed to 32? What means 32?
>>
>> It means 90 degree shift for value 32. This configuration comes from
>> ZTE engineer as I do not have hardware for this tuning. Let's just
>> keep it with adding more comments till tuning is needed.
>>
>>>
>>>> +     if (ret < 0)
>>>> +             return -EIO;
>>>> +
>>>> +     return 0;
>>>> +}
>>>> +
>>>> +static int dw_mci_zx_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
>>>> +{
>>>> +     struct dw_mci *host = slot->host;
>>>> +
>>>> +     if (host->verid == 0x290a) /* emmc */
>>>> +             return dw_mci_zx_emmc_execute_tuning(slot, opcode);
>>>
>>> I didn't know why you check host->verid is 2.90a..
>>> Is there any reason?
>> There are two version DW MMC IP on this SoC and different
>> configuration is needed for them. I do not have hardware for tuning
>> version 210A timing and will be added later.
>
> you means there are two IP version with same SoC?
>
> Best Regards,
> Jaehoon Chung

Right, two version IP exist on the same SoC.

>
>>
>>>
>>>> +
>>>> +     return 0;
>>>> +}
>>>> +
>>>> +static int dw_mci_zx_parse_dt(struct dw_mci *host)
>>>> +{
>>>> +     struct device_node *np = host->dev->of_node;
>>>> +     struct device_node *node;
>>>> +     struct dw_mci_zx_priv_data *priv;
>>>> +     struct regmap *sysc_base;
>>>> +     int ret;
>>>> +
>>>> +     node = of_parse_phandle(np, "zte,aon-syscon", 0);
>>>> +     if (node) {
>>>> +             sysc_base = syscon_node_to_regmap(node);
>>>> +             of_node_put(node);
>>>
>>> Use the syscon_regmap_lookup_by_phandle(). It's same behavior.
>> Will do.
>>>
>>>> +
>>>> +             if (IS_ERR(sysc_base)) {
>>>> +                     ret = PTR_ERR(sysc_base);
>>>> +                     if (ret != -EPROBE_DEFER)
>>>> +                             dev_err(host->dev, "Can't get syscon: %d\n",
>>>> +                                     ret);
>>>> +                     return ret;
>>>> +             }
>>>> +     }
>>>> +
>>>> +     priv = devm_kzalloc(host->dev, sizeof(*priv), GFP_KERNEL);
>>>> +     if (!priv)
>>>> +             return -ENOMEM;
>>>> +     priv->sysc_base = sysc_base;
>>>
>>> Is there no case that sysc_base is NULL?
>>
>> sysc_base is needed only for eMMC. So it is NULL for SD/MMC cases, and
>> we can save memory for SD/MMC cases here :)
>>
>>>
>>>> +     host->priv = priv;
>>>> +
>>>> +     return 0;
>>>> +}
>>>> +
>>>> +static unsigned long zx_dwmmc_caps[3] = {
>>>> +     MMC_CAP_CMD23,
>>>> +     MMC_CAP_CMD23,
>>>> +     MMC_CAP_CMD23,
>>>> +};
>>>> +
>>>> +static const struct dw_mci_drv_data zx_drv_data = {
>>>> +     .caps                   = zx_dwmmc_caps,
>>>> +     .execute_tuning         = dw_mci_zx_execute_tuning,
>>>> +     .prepare_hs400_tuning   = dw_mci_zx_prepare_hs400_tuning,
>>>> +     .parse_dt               = dw_mci_zx_parse_dt,
>>>> +};
>>>> +
>>>> +static const struct of_device_id dw_mci_zx_match[] = {
>>>> +     { .compatible = "zte,dw-mshc", .data = &zx_drv_data},
>>>> +};
>>>> +MODULE_DEVICE_TABLE(of, dw_mci_zx_match);
>>>> +
>>>> +static int dw_mci_zx_probe(struct platform_device *pdev)
>>>> +{
>>>> +     const struct dw_mci_drv_data *drv_data;
>>>> +     const struct of_device_id *match;
>>>> +
>>>> +     match = of_match_node(dw_mci_zx_match, pdev->dev.of_node);
>>>> +     drv_data = match->data;
>>>> +
>>>> +     return dw_mci_pltfm_register(pdev, drv_data);
>>>> +}
>>>> +
>>>> +static const struct dev_pm_ops dw_mci_zx_dev_pm_ops = {
>>>> +     SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
>>>> +                             pm_runtime_force_resume)
>>>> +     SET_RUNTIME_PM_OPS(dw_mci_runtime_suspend,
>>>> +                        dw_mci_runtime_resume,
>>>> +                        NULL)
>>>> +};
>>>> +
>>>> +static struct platform_driver dw_mci_zx_pltfm_driver = {
>>>> +     .probe          = dw_mci_zx_probe,
>>>> +     .remove         = dw_mci_pltfm_remove,
>>>> +     .driver         = {
>>>> +             .name           = "dwmmc_zx",
>>>> +             .of_match_table = dw_mci_zx_match,
>>>> +             .pm             = &dw_mci_zx_dev_pm_ops,
>>>> +     },
>>>> +};
>>>> +
>>>> +module_platform_driver(dw_mci_zx_pltfm_driver);
>>>> +
>>>> +MODULE_DESCRIPTION("ZTE emmc/sd driver");
>>>> +MODULE_LICENSE("GPL v2");
>>>> diff --git a/drivers/mmc/host/dw_mmc-zx.h b/drivers/mmc/host/dw_mmc-zx.h
>>>> new file mode 100644
>>>> index 0000000..b1aac52
>>>> --- /dev/null
>>>> +++ b/drivers/mmc/host/dw_mmc-zx.h
>>>> @@ -0,0 +1,23 @@
>>>> +#ifndef _DW_MMC_ZX_H_
>>>> +#define _DW_MMC_ZX_H_
>>>> +
>>>> +/* dll reg offset*/
>>>> +#define LB_AON_EMMC_CFG_REG0  0x1B0
>>>> +#define LB_AON_EMMC_CFG_REG1  0x1B4
>>>> +#define LB_AON_EMMC_CFG_REG2  0x1B8
>>>> +
>>>> +/* LB_AON_EMMC_CFG_REG0 register defines */
>>>> +#define PARA_DLL_START_POINT(x)      (((x) & 0xFF) << 0)
>>>> +#define DLL_REG_SET          BIT(8)
>>>> +#define PARA_DLL_LOCK_NUM(x) (((x) & 7) << 16)
>>>> +#define PARA_PHASE_DET_SEL(x)        (((x) & 7) << 20)
>>>> +#define PARA_DLL_BYPASS_MODE BIT(23)
>>>> +#define PARA_HALF_CLK_MODE   BIT(24)
>>>
>>> PAR_PHASE_DET_SEL/PARA_DLL_BYPASS_MODE_BIT/PARA_HALF_CLK_MODE are never used anywhere.
>>>
>>>> +
>>>> +/* LB_AON_EMMC_CFG_REG1 register defines */
>>>> +#define READ_DQS_DELAY(x)    (((x) & 0x7F) << 0)
>>>> +#define READ_DQS_BYPASS_MODE BIT(7)
>>>> +#define CLK_SAMP_DELAY(x)    (((x) & 0x7F) << 8)
>>>> +#define CLK_SAMP_BYPASS_MODE BIT(15)
>>>
>>> Also READ_DQS_BYPASS_MODe/CLK_SAMP_BYBASS_MODE didnt used anywhere.
>>>
>>>
>>> Hmm. These are not dwmmc host controller's register.
>>> So If you needs to add these defines..I think you needs to add dessriptions in more detail.
>>>
>>> At least..Which board's DLL reg offset.
>>>
>>> Best Regards,
>>> Jaehoon Chung
>>>
>>>> +
>>>> +#endif /* _DW_MMC_ZX_H_ */
>>>>
>>>
>>
>>
>>
>
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