[PATCH V5 1/2] mmc: add OpenPiton mmc support
Tianrui Wei
tianrui-wei at outlook.com
Sun Jun 6 18:57:06 CEST 2021
Dear Sean,
Many thanks for taking the time and energy to review our patches ( again )
And sorry about not responding or not implementing them. I'll go through
them one by one and try to doing so in the future :P
On 6/7/21 12:34 AM, Sean Anderson wrote:
> On 6/4/21 12:52 AM, Tianrui Wei wrote:
>> From: Tianrui Wei <tianrui-wei at outlook.com>
>> Date: Fri, 4 June 2021 12:45:29 +0800
>> Subject: [PATCH v5 1/2] mmc: add OpenPiton mmc support
>>
>> This patch adds mmc support for OpenPiton board.
>>
>> Changelog:
>>
>> v5: move definitions around, changed some incompatible type information
>>
>> 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 | 174 +++++
>> 3 files changed, 182 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
>
> We already know it's for U-Boot ;)
:P
>
>> + OpenPiton SoC
>
> Please add a bit more than this. In particular, it would be useful to
> note that this is an "emulated" device where the host does all of the
> work.
Will do :P
>
>> +
>> 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
>> 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..2b2d5756
>> --- /dev/null
>> +++ b/drivers/mmc/piton_mmc.c
>> @@ -0,0 +1,174 @@
>> +// 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
>> + * This file is adapted from tegra_mmc.c
>> + * Tianrui Wei <tianrui-wei at outlook.com>
>> + */
>> +
>> +#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;
>> +};
>> +
>> +struct piton_mmc_priv {
>> + u64 piton_mmc_base_addr; /* peripheral id */
>
> Again, please use void __iomem *.
Sorry, forgot this change :(
>
>> +};
>> +
>> +/*
>> + * see mmc_read_blocks to see how it is used.
>> + * start block is hidden at cmd->arg
>
> Hidden?
I wrote this comment a long time ago, I'll comment it out.
>
>> + * also, initialize the block size at init
>> + */
>> +static int piton_mmc_send_cmd(struct udevice *dev, struct mmc_cmd *cmd,
>> + struct mmc_data *data)
>
> Nit: alignment
I'm not sure how to align this? Should I align the struct in the first line
and the second line? It appears so in my email client :P
>
>> +{
>> + /* check first if this is a pure command */
>> + if (!data)
>> + return 0;
>
> Variable declarations come before code.
Will do :P
>
>> +
>> + u64 byte_cnt, start_block, start_addr;
>
> I think these should be size_t, since you use it for pointer
> arithmetic.
Will do :P
>
>> +
>> + struct piton_mmc_priv *priv = dev_get_priv(dev);
>> + unsigned long *buff = (unsigned long *)data->dest;
>> +
>> + start_addr = priv->piton_mmc_base_addr + (start_block);
>> + byte_cnt = data->blocks * data->blocksize;
>
> What should happen if (byte_cnt & 3)?
The 1th or 3rd byte will be read into buf,
>
>> + start_block = cmd->cmdarg;
>> +
>> + /* if there is a read */
>> + if (data->flags & MMC_DATA_READ) {
>> + for (u64 i = 0; i < byte_cnt; i += 4) {
>
> Declare i with the rest of the variables.
>
>> + *(buff) = readl((void *)(start_addr + i));
>
> I think this could be rewritten as
>
> size_t byte_cnt;
> u32 *buff, *start_addr;
>
> /* ... */
>
> for (byte_cnt = /* ... */; byte_cnt; byte_cnt -= sizeof(u32));
> *buff++ = readl(start_addr++);
>
> Which more closely follows the model of memcpy. Speaking of which, I
> thought you were going to use it:
Thanks for the style suggestion :P I'll use that
>
>> Scratch the previous email, I stand corrected. You're right about
>> memcpy could work, thanks for the great suggestion :P
>
> What happened to that?
I checked with Professor Balkind regarding memcpy, and there were some
issues with it because it's accessing an I/O device we need to maintain
particular alignment which memcpy might not do, so we're sticking with
the old implementation.
>
>> + buff++;
>> + }
>> + } else {
>> + /* else there is a write
>> + * we don't handle write, so error right away
>> + */
>> + return -ENODEV;
>
> Please use -ENOSYS. See [1] for details.
Will do :P
>
> In general, several of my comments on your previous patch are still
> unaddressed. I would like if you could either respond to them with your
> reasoning for not addressing them, or implement them.
Will definitely do that in the future :P
Tianrui
>
> --Sean
>
>
> [1] https://apac01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fu-boot.readthedocs.io%2Fen%2Flatest%2Fdevelop%2Fdriver-model%2Fdesign.html%23error-codes&data=04%7C01%7C%7Cf72fe8fce39746732fdd08d92908e60b%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637585940462351512%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=ncVph6yZoK4UaDnH2f3js3dsxtwNWih1fhI%2BwCq6jfw%3D&reserved=0
>
>> + }
>> +
>> + 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,
>> + .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),
>> +};
>>
>
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