[PATCH V4 1/2] mmc: add OpenPiton mmc support

Tianrui Wei tianrui-wei at outlook.com
Fri May 7 04:57:48 CEST 2021


Hi Sean,


Thanks for reviewing the patches, I'll fix the initialization thing and 
the tegra_mmc credit :P

On 5/7/2021 10:55 AM, Sean Anderson wrote:
> On 5/6/21 10:50 PM, Tianrui Wei wrote:
>> Hi Sean,
>>
>> Many thanks for taking your valuable time to review our patch and give
>> suggestions. I'll improve both our patches accordingly. Just for the
>> record, what would be the exact command you'd recommend to run
>> checkpatch.pl? Because it only showed one warning about me not putting
>> my name on the MAINTAINERS file on this patch.
>
> Huh. I would have expected checkpatch to catch the variable
> initialization thing, but I guess it didn't.
>
>>
>>
>> Many thanks,
>>
>> Tianrui
>>
>> On 5/7/2021 10:43 AM, Sean Anderson wrote:
>>> On 5/5/21 11:40 PM, Tianrui Wei wrote:
>>>> From: Tianrui Wei <tianrui-wei at outlook.com>
>>>> Date: Thu, 6 May 2021 11:30:20 +0800
>>>> Subject: [PATCH V4 1/2] mmc: add OpenPiton mmc support
>>>>
>>>> This patch adds mmc support for OpenPiton.
>>>> Specifically, some dts bindings were not used because
>>>> our mmc controller doens't have those configuration
>>>> options, it only exposes a dummy mmap interface for
>>>> CPU.
>>>
>>> Please wrap your commit messages to 75 characterss, not 56 ;)
>>>
>>>>
>>>> Signed-off-by: Tianrui Wei <tianrui-wei at outlook.com>
>>>> Signed-off-by: Jonathan Balkind <jbalkind at ucsb.edu>
>>>> ---
>>>>
>>>>   drivers/mmc/Kconfig                     |   7 +
>>>>   drivers/mmc/Makefile                    |   1 +
>>>>   drivers/mmc/piton_mmc.c                 | 172 +++++
>>>>   3 files changed, 180 insertions(+)
>>>>   create mode 100644 drivers/mmc/piton_mmc.c
>>>>
>>>> diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
>>>> index 14d79139..1038800f 100644
>>>> --- a/drivers/mmc/Kconfig
>>>> +++ b/drivers/mmc/Kconfig
>>>> @@ -707,6 +707,13 @@ config MMC_SUNXI_HAS_MODE_SWITCH
>>>>       bool
>>>>       depends on MMC_SUNXI
>>>>   +config MMC_PITON
>>>> +    bool "MMC support for openpiton SoC"
>>>> +  depends on DM_MMC && BLK
>>>> +    help
>>>> +    This driver enables SD card support in U-Boot port for
>>>> +    OpenPiton SoC
>>>> +
>>>>   config GENERIC_ATMEL_MCI
>>>>       bool "Atmel Multimedia Card Interface support"
>>>>       depends on DM_MMC && BLK && ARCH_AT91
>>>> diff --git a/drivers/mmc/Makefile b/drivers/mmc/Makefile
>>>> index 1c849cba..698dfe05 100644
>>>> --- a/drivers/mmc/Makefile
>>>> +++ b/drivers/mmc/Makefile
>>>> @@ -71,6 +71,7 @@ obj-$(CONFIG_MMC_SDHCI_XENON)        += 
>>>> xenon_sdhci.o
>>>>   obj-$(CONFIG_MMC_SDHCI_ZYNQ)        += zynq_sdhci.o
>>>>     obj-$(CONFIG_MMC_SUNXI)            += sunxi_mmc.o
>>>> +obj-$(CONFIG_MMC_PITON)         += piton_mmc.o
>>>
>>> Fix indentation. And please place this object in alphabetical order.
>>>
>>>>   obj-$(CONFIG_MMC_UNIPHIER)        += tmio-common.o uniphier-sd.o
>>>>   obj-$(CONFIG_RENESAS_SDHI)        += tmio-common.o renesas-sdhi.o
>>>>   obj-$(CONFIG_MMC_BCM2835)        += bcm2835_sdhost.o
>>>> diff --git a/drivers/mmc/piton_mmc.c b/drivers/mmc/piton_mmc.c
>>>> new file mode 100644
>>>> index 00000000..266e26d8
>>>> --- /dev/null
>>>> +++ b/drivers/mmc/piton_mmc.c
>>>> @@ -0,0 +1,172 @@
>>>> +// SPDX-License-Identifier: GPL-2.0+
>>>> +/*
>>>> + * (C) Copyright 2009 SAMSUNG Electronics
>>>> + * Minkyu Kang <mk7.kang at samsung.com>
>>>> + * Jaehoon Chung <jh80.chung at samsung.com>
>>>> + * Portions Copyright 2011-2019 NVIDIA Corporation
>>>> + * Portions Copyright 2021 Tianrui Wei
>>>> + * Tianrui Wei <tianrui-wei at outlook.com>
>>>
>>> This is quite the list of authors. Where does this file come from?
>>
>>
>> This file was adapted from a Samsung mmc file, so I kept the original 
>> authors.
>
> Can you add a note along the lines of "Adapted from tegra_mmc.c" for the
> curiosity of future readers :)
>
> --Sean
>
>>
>>>
>>>> + */
>>>> +
>>>> +#include <asm/gpio.h>
>>>> +#include <asm/io.h>
>>>> +#include <common.h>
>>>> +#include <dm.h>
>>>> +#include <errno.h>
>>>> +#include <linux/bitops.h>
>>>> +#include <linux/types.h>
>>>> +#include <linux/delay.h>
>>>> +#include <linux/err.h>
>>>> +#include <log.h>
>>>> +#include <div64.h>
>>>> +#include <mmc.h>
>>>> +
>>>> +struct piton_mmc_plat {
>>>> +    struct mmc_config cfg;
>>>> +    struct mmc mmc;
>>>> +};
>>>
>>> Is platdata used? I don't see it in 2/2.
>>>
>>>> +
>>>> +struct piton_mmc_priv {
>>>> +    u64 piton_mmc_base_addr; /* peripheral id */
>>>
>>> This should be void __iomem *.
>>>
>>>> +};
>>>> +
>>>> +/*
>>>> + * see mmc_read_blocks to see how it is used.
>>>> + * start block is hidden at cmd->arg
>>>> + * also, initialize the block size at init
>>>> + */
>>>> +static int piton_mmc_send_cmd(struct udevice *dev, struct mmc_cmd 
>>>> *cmd,
>>>> +                  struct mmc_data *data)
>>>> +{
>>>> +    /* check first if this is a pure command */
>>>> +    if (!data)
>>>> +        return 0;
>>>
>>> Please place definitions before code (and please run checkpatch).
>>>
>>>> +
>>>> +    u64 byte_cnt = data->blocks * data->blocksize;
>>>> +    u64 start_block = cmd->cmdarg;
>>>> +    unsigned int *buff = (unsigned int *)data->dest;
>>>
>>> Why is buff an unsigned int? If you are using readl, shouldn't it be a
>>> long?
>>>
>>>> +
>>>> +    struct piton_mmc_priv *priv = dev_get_priv(dev);
>>>> +    u64 start_addr = priv->piton_mmc_base_addr + (start_block);
>>>> +
>>>> +    /* if there is a read */
>>>> +    if (data->flags & MMC_DATA_READ) {
>>>> +        for (u64 i = 0; i < byte_cnt; i += 4) {
>>>> +            *(buff) = readl((void *)(start_addr + i));
>>>> +            buff++;
>>>> +        }
>>>
>>> Can you use memcpy_fromio here?
>>>
>>>> +    } else {
>>>> +        /* else there is a write
>>>> +         * we don't handle write, so error right away
>>>> +         */
>>>> +        return -ENODEV;
>>>
>>> Please use -ENOSYS.
>>>
>>>> +    }
>>>> +
>>>> +    return 0;
>>>> +}
>>>> +
>>>> +static int piton_mmc_ofdata_to_platdata(struct udevice *dev)
>>>> +{
>>>> +    struct piton_mmc_priv *priv = dev_get_priv(dev);
>>>> +    struct piton_mmc_plat *plat = dev_get_platdata(dev);
>>>> +    struct mmc_config *cfg;
>>>> +    struct mmc *mmc;
>>>> +    /* fill in device description */
>>>> +    struct blk_desc *bdesc;
>>>> +
>>>> +    priv->piton_mmc_base_addr = dev_read_addr(dev);
>>>> +    cfg = &plat->cfg;
>>>> +    cfg->name = "PITON MMC";
>>>> +    cfg->host_caps = MMC_MODE_8BIT;
>>>> +    cfg->f_max = 100000;
>>>> +    cfg->f_min = 400000;
>>>> +    cfg->voltages = MMC_VDD_21_22;
>>>> +
>>>> +    mmc = &plat->mmc;
>>>> +    mmc->read_bl_len = MMC_MAX_BLOCK_LEN;
>>>> +    mmc->capacity_user = 0x100000000;
>>>> +    mmc->capacity_user *= mmc->read_bl_len;
>>>> +    mmc->capacity_boot = 0;
>>>> +    mmc->capacity_rpmb = 0;
>>>> +    for (int i = 0; i < 4; i++)
>>>> +        mmc->capacity_gp[i] = 0;
>>>> +    mmc->capacity = 0x2000000000ULL;
>>>> +    mmc->has_init = 1;
>>>> +
>>>> +    bdesc = mmc_get_blk_desc(mmc);
>>>> +    bdesc->lun = 0;
>>>> +    bdesc->hwpart = 0;
>>>> +    bdesc->type = 0;
>>>> +    bdesc->blksz = mmc->read_bl_len;
>>>> +    bdesc->log2blksz = LOG2(bdesc->blksz);
>>>> +    bdesc->lba = lldiv(mmc->capacity, mmc->read_bl_len);
>>>> +
>>>> +    return 0;
>>>> +}
>>>> +
>>>> +/* test if piton has the micro mmc card present
>>>> + * always return 1, which means present
>>>> + */
>>>> +static int piton_mmc_getcd(struct udevice *dev)
>>>> +{
>>>> +    /*
>>>> +     * always return 1
>>>> +     */
>>>> +    return 1;
>>>> +}
>>>> +
>>>> +/* dummy function, piton_mmc don't need initialization
>>>> + * in hw
>>>> + */
>>>> +static const struct dm_mmc_ops piton_mmc_ops = {
>>>> +    .send_cmd = piton_mmc_send_cmd,
>>>> +    .set_ios = piton_mmc_set_ios,
>>>> +    .get_cd = piton_mmc_getcd,
>>>> +};
>>>> +
>>>> +static int piton_mmc_probe(struct udevice *dev)
>>>> +{
>>>> +    struct mmc_uclass_priv *upriv = dev_get_uclass_priv(dev);
>>>> +    struct piton_mmc_plat *plat = dev_get_platdata(dev);
>>>> +    struct mmc_config *cfg = &plat->cfg;
>>>> +
>>>> +    cfg->name = dev->name;
>>>> +    upriv->mmc = &plat->mmc;
>>>> +    upriv->mmc->has_init = 1;
>>>> +    upriv->mmc->capacity = 0x2000000000ULL;
>>>> +    upriv->mmc->read_bl_len = MMC_MAX_BLOCK_LEN;
>>>> +
>>>> +    return 0;
>>>> +}
>>>> +
>>>> +static int piton_mmc_bind(struct udevice *dev)
>>>> +{
>>>> +    struct piton_mmc_plat *plat = dev_get_platdata(dev);
>>>> +    struct mmc_config *cfg = &plat->cfg;
>>>> +
>>>> +    cfg->name = dev->name;
>>>> +    cfg->host_caps = MMC_MODE_HS_52MHz | MMC_MODE_HS | MMC_MODE_8BIT;
>>>> +    cfg->voltages = MMC_VDD_165_195 | MMC_VDD_32_33 | MMC_VDD_33_34;
>>>> +    cfg->f_min = 1000000;
>>>> +    cfg->f_max = 52000000;
>>>> +    cfg->b_max = U32_MAX;
>>>> +
>>>> +    return mmc_bind(dev, &plat->mmc, cfg);
>>>> +}
>>>> +
>>>> +static const struct udevice_id piton_mmc_ids[] = {
>>>> +        {.compatible = "openpiton,piton-mmc"},
>>>> +        { /* sentinel */ }
>>>> +};
>>>> +
>>>> +U_BOOT_DRIVER(piton_mmc_drv) = {
>>>> +    .name = "piton_mmc",
>>>> +    .id = UCLASS_MMC,
>>>> +    .of_match = piton_mmc_ids,
>>>> +    .ofdata_to_platdata = piton_mmc_ofdata_to_platdata,
>>>> +    .bind = piton_mmc_bind,
>>>> +    .probe = piton_mmc_probe,
>>>> +    .ops = &piton_mmc_ops,
>>>> +    .platdata_auto_alloc_size = sizeof(struct piton_mmc_plat),
>>>> +    .priv_auto_alloc_size = sizeof(struct piton_mmc_priv),
>>>> +};
>>>>
>>>
>>> --Sean
>


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