[RESEND PATCH v7 2/2] mmc: openpiton: add piton_mmc driver

[Jaehoon Chung]

On 6/30/21 3:01 AM, Tianrui Wei wrote:
> This commit adds support to piton_mmc driver for OpenPiton-riscv64
> This driver has many things set as preconfigured because the hardware
> automatically configures most of the settings during startup.
> 
> - V6
>   . change type of address
>   . move declarations ahead
>   . loop style update
> - V7
>   . dm updates
>   . fix indentations
>   . style fixes to improve readability
>   . add write support for mmc cards
> 
> Signed-off-by: Tianrui Wei <tianrui-wei at outlook.com>
> Signed-off-by: Jonathan Balkind <jbalkind at ucsb.edu>
> ---
>  drivers/mmc/Kconfig     |   9 ++
>  drivers/mmc/Makefile    |   1 +
>  drivers/mmc/piton_mmc.c | 181 ++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 191 insertions(+)
>  create mode 100644 drivers/mmc/piton_mmc.c
> 
> diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
> index 8901456967..4948e194e7 100644
> --- a/drivers/mmc/Kconfig
> +++ b/drivers/mmc/Kconfig
> @@ -727,6 +727,15 @@ 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 selects support for the SD host controller on OpenPiton SoC.
> +	  Note that this SD controller directly exposes the contents of the
> +	  SD card as memory mapped, so there is no manual configuration
> +	  required
> +
>  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 89d6af3db3..d96ac90719 100644
> --- a/drivers/mmc/Makefile
> +++ b/drivers/mmc/Makefile
> @@ -72,6 +72,7 @@ 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 0000000000..8517ec8410
> --- /dev/null
> +++ b/drivers/mmc/piton_mmc.c
> @@ -0,0 +1,181 @@
> +// 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 <div64.h>
> +#include <dm.h>
> +#include <errno.h>
> +#include <linux/bitops.h>
> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <linux/types.h>
> +#include <linux/sizes.h>
> +#include <log.h>
> +#include <mmc.h>
> +
> +
> +#define PITON_MMC_DUMMY_F_MAX 20000000
> +#define PITON_MMC_DUMMY_F_MIN 10000000
> +#define PITON_MMC_DUMMY_CAPACITY SZ_4G << 3
> +#define PITON_MMC_DUMMY_B_MAX SZ_4G
> +
> +struct piton_mmc_plat {
> +	struct mmc_config cfg;
> +	struct mmc mmc;
> +};
> +
> +struct piton_mmc_priv {
> +	void __iomem *piton_mmc_base_addr; /* peripheral id */

It's for piton. It can be used to base_addr from piton_mmc_base_addr.

> +};
> +
> +/*
> + * see mmc_read_blocks to see how it is used.
> + * start block is hidden at cmd->arg
> + * also, initialize the block size at init
> + */

It seems that not need to describe this comment.

> +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;
> +
> +	struct piton_mmc_priv *priv = dev_get_priv(dev);
> +	u32 *buff, *start_addr, *write_src;
> +	size_t byte_cnt, start_block;
> +
> +	buff = (u32 *)data->dest;
> +	write_src = (u32 *)data->src;
> +	start_block = cmd->cmdarg;
> +	start_addr = priv->piton_mmc_base_addr + start_block;
> +
> +	/* if there is a read */
> +	if (data->flags & MMC_DATA_READ) {
> +		for (byte_cnt = data->blocks * data->blocksize; byte_cnt;
> +				 byte_cnt -= sizeof(u32)) {
> +			*buff++ = readl(start_addr++);
> +		}
> +	} else {
> +		for (byte_cnt = data->blocks * data->blocksize; byte_cnt;
> +				 byte_cnt -= sizeof(u32)) {
> +			writel(*write_src++,start_addr++);
> +		}

Can be reduced code.

for (byte_cnt = data->blocks * data->blocksize; byte_cnt; byte_cnt -= sizeof((u32)) {
	if (data->flags & MMC_DATA_READ)
		...
	else
		...
}


> +
> +	}
> +
> +	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_plat(dev);
> +	struct mmc_config *cfg;
> +	struct mmc *mmc;
> +	/* fill in device description */
> +	struct blk_desc *bdesc;
> +
> +	priv->piton_mmc_base_addr = (void *)dev_read_addr(dev);
> +	cfg = &plat->cfg;
> +	cfg->name = "PITON MMC";
> +	cfg->host_caps = MMC_MODE_8BIT;
> +	cfg->f_max = PITON_MMC_DUMMY_F_MAX;
> +	cfg->f_min = PITON_MMC_DUMMY_F_MIN;
> +	cfg->voltages = MMC_VDD_21_22;
> +
> +	mmc = &plat->mmc;
> +	mmc->read_bl_len = MMC_MAX_BLOCK_LEN;
> +	mmc->capacity_user = PITON_MMC_DUMMY_CAPACITY;
> +	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 = PITON_MMC_DUMMY_CAPACITY;
> +	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 the micro sd card is present
> + * always return 1, which means present
> + */

Not need to add this comment.

> +static int piton_mmc_getcd(struct udevice *dev)
> +{
> +	/*
> +	 * always return 1
> +	 */
> +	return 1;
> +}
> +
> +/* dummy function, piton_mmc don't need initialization
> + * in hw
> + */

Remove. Which function is dummy? 

> +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_plat(dev);
> +	struct mmc_config *cfg = &plat->cfg;
> +
> +	cfg->name = dev->name;
> +	upriv->mmc = &plat->mmc;
> +	upriv->mmc->has_init = 1;
> +	upriv->mmc->capacity = PITON_MMC_DUMMY_CAPACITY;
> +	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_plat(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 = PITON_MMC_DUMMY_F_MIN;
> +	cfg->f_max = PITON_MMC_DUMMY_F_MAX;
> +	cfg->b_max = MMC_MAX_BLOCK_LEN;
> +
> +	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,
> +	.of_to_plat = piton_mmc_ofdata_to_platdata,
> +	.bind = piton_mmc_bind,
> +	.probe = piton_mmc_probe,
> +	.ops = &piton_mmc_ops,
> +	.plat_auto = sizeof(struct piton_mmc_plat),
> +	.priv_auto = sizeof(struct piton_mmc_priv),
> +};
>