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

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2016-10-24 20:29 GMT+08:00 Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>:
> 在 2016/10/24 17:11, Jun Nie 写道:
>>
>> 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
>> +       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..d0e4ef2
>> --- /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/platform_device.h>
>> +#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>
> to keep alphabetical order

Will do.

>
>> +#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)
>> +
>> +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)
>
>
> I don't know if this is expected/legit way to control the delay/phase
> by adding code here. It looks more general to me that we should use
> clk_{set,get}_phase API.

The phase control register reside in a system controller, not a
standard clock controller. The register control data sampling phase
and bypass mode etc, but no clk rate/mux. So it will take more code
and ugly logic to expose a clk_* API based on such register.

>
>
>> +{
>> +       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;
>> +
>> +       ret = regmap_write(sysc_base, LB_AON_EMMC_CFG_REG0,
>> +                          PARA_DLL_START_POINT(4) |
>> PARA_DLL_LOCK_NUM(4));
>> +       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));
>> +               clksel |= (delay << 8);
>> +       } else {
>> +               clksel &= ~(READ_DQS_DELAY(0x7F));
>> +               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);
>> +
>> +       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;
>> +
>> +               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);
>> +       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);
>> +
>> +       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);
>> +
>> +               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;
>> +       host->priv = priv;
>> +
>> +       return 0;
>> +}
>> +
>> +static unsigned long zx_dwmmc_caps[3] = {
>> +       MMC_CAP_HW_RESET,
>> +       0,
>> +       0,
>> +};
>> +
>
>
> just a thought, maybe you could add the cap-mmc-hw-reset for your
> emmc node on the DT as
>
> 1) you could save some bits here
> 2) Moreover, it's related to the board design since it isn't
> guaranteed that the  hw_rest pin won't be used for other purpose..
>
You are right.

>
>> +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)
>> +
>> +/* 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)
>> +
>> +#endif /* _DW_MMC_ZX_H_ */
>>
>
>
> --
> Best Regards
> Shawn Lin
>
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