[PATCH V2 1/2] mmc: add OpenPiton mmc support

[Jaehoon Chung]

Dear Tianrui,

On 4/22/21 3:19 PM, Tianrui Wei wrote:
> This patch adds mmc support for OpenPiton.
> 
> Signed-off-by: Tianrui Wei <tianrui-wei at outlook.com>
> Signed-off-by: Jonathan Balkind <jbalkind at ucsb.edu>
> 
> ---
> 
>  drivers/mmc/Kconfig                     |   6 +
>  drivers/mmc/Makefile                    |   1 +
>  drivers/mmc/piton_mmc.c                 | 177 +++++
>  3 files changed, 184 insertions(+)
>  create mode 100644 drivers/mmc/piton_mmc.c
> 
> diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
> index 14d79139..41822c39 100644
> --- a/drivers/mmc/Kconfig
> +++ b/drivers/mmc/Kconfig
> @@ -707,6 +707,12 @@ 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
> +
>  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..f2ceb87f
> --- /dev/null
> +++ b/drivers/mmc/piton_mmc.c
> @@ -0,0 +1,177 @@
> +// 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>
> + */
> +
> +#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 */
> +};
> +
> +/*
> + * 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

Remove all "//" comment.
If you want to add some comment, add comment with "/* *"

e.g)
/* Check first if this is a pure command */

> +	if (data == NULL) {
> +		return 0;
> +	}
> +
> +	// byte count counts all the bytes required for this command

Not need. Remove, plz.

> +	u64 byte_cnt = data->blocks * data->blocksize;
> +	// get which block in mmc card to start from

Ditto

> +	u64 start_block = cmd->cmdarg;
> +	// buff points to the address we store the data stored at mmc card

Ditto.

> +	unsigned *buff = (unsigned int *) data->dest;
> +
> +	struct piton_mmc_priv *priv = dev_get_priv(dev);
> +	// start address denotes the absolute address where the transmission start

Ditto.

> +	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++;
> +		}
> +	} else {
> +		/* else there is a write
> +		 * we don't handle write, so error right away
> +		 */
> +		return -ENODEV;
> +	}
> +
> +	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;

If you can use mmc_of_parse() with dt, it can be removed.

> +	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;
> +}
> +
> +/*
> + * currently, this is ignored. we only use fixed speed
> + */
> +static int piton_mmc_set_ios(struct udevice *dev) { return 0; }

Remove this, plz. If you nened to add some specific things for OpenPiton, can be added at that time.

> +
> +/* test if piton has the micro mmc card present
> + * always return 1, which means present
> + */
> +static int piton_mmc_getcd(struct udevice *dev) { return 1; }

static int piton_mmc_getcd(struct udevice *dev) {
	/* 
	 * Always return 1,...
	 */
	return 1;
}

Or use non-removable in device-tree.


> +
> +/* dummy function, piton_mmc don't need initialization in hw*/
> +static const struct dm_mmc_ops piton_mmc_ops = {
> +	// send a command to mmc device

Remove, plz. It's generic callback, not need to describe what it is.

> +	.send_cmd = piton_mmc_send_cmd,
> +	// set iospeed

Ditto.

> +	.set_ios = piton_mmc_set_ios,
> +	// detect if card is present

Ditto.

> +	.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),
> +};
>