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

Sean Anderson seanga2 at gmail.com
Fri May 7 04:55:34 CEST 2021


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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