Re: [PATCH V8 2/2] mmc: OCTEON: Add host driver for OCTEON MMC controller.

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On 12 July 2016 at 20:18, Steven J. Hill <steven.hill@xxxxxxxxxx> wrote:
> The OCTEON MMC controller is currently found on cn61XX and cn71XX
> devices. Device parameters are configured from device tree data.
> eMMC, MMC and SD devices are supported. Tested on Rhino labs UTM8
> and Cavium CN7130 board.
>
> Signed-off-by: Steven J. Hill <steven.hill@xxxxxxxxxx>
> Acked-by: David Daney <david.daney@xxxxxxxxxx>
>
> ---
> v8:
> - Convert driver to use readq()/writeq() functions.
> - Work around legacy u-boot device trees.
> - Enable EMMC interrupts properly.
> - Support DDR signalling. The timings are tighter, so
>   there may be failures with some FDT settings.
> - Quiesce the device by calling mmc_remove_host() and
>   mmc_free_host() when unloading the driver.
> - Set MIO_BOOT_CTL on cn70xx to select proper mmc mode
>   which is part of acquiring the bus.
> - Use of_property_read_u32() helper for cleaner device
>   tree accesses.
> - Properly implement multi-block DMA. The Octeon's DMA
>   enginer cannot do scatter-gather.
> - Add driver parameters to limit multi-block transfers.
> - Use octeon_bootbus_sem.
> - Improve GPIO support and make actual requests to use the
>   GPIO lines before using and freeing them after.
>
> v7:
> - Revert to legacy device tree bindings handled in driver
> - Tone down the warning printed when legacy bindings in use
>
> v6:
> - Split up patch
> - Moved device tree fixup to platform code
>
> Signed-off-by: Steven J. Hill <Steven.Hill@xxxxxxxxxx>
> ---
>  drivers/mmc/host/Kconfig      |   10 +
>  drivers/mmc/host/Makefile     |    1 +
>  drivers/mmc/host/octeon_mmc.c | 1331 +++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 1342 insertions(+)
>  create mode 100644 drivers/mmc/host/octeon_mmc.c
>
> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> index 0aa484c..7ef7f8b 100644
> --- a/drivers/mmc/host/Kconfig
> +++ b/drivers/mmc/host/Kconfig
> @@ -332,6 +332,16 @@ config MMC_SDHCI_IPROC
>
>           If unsure, say N.
>
> +config MMC_OCTEON
> +       tristate "Cavium OCTEON Multimedia Card Interface support"
> +       depends on CAVIUM_OCTEON_SOC
> +       help
> +         This selects Cavium OCTEON Multimedia card Interface.
> +         If you have an OCTEON board with a Multimedia Card slot,
> +         say Y or M here.
> +
> +         If unsure, say N.
> +
>  config MMC_MOXART
>         tristate "MOXART SD/MMC Host Controller support"
>         depends on ARCH_MOXART && MMC
> diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
> index af918d2..c43bd7d 100644
> --- a/drivers/mmc/host/Makefile
> +++ b/drivers/mmc/host/Makefile
> @@ -21,6 +21,7 @@ obj-$(CONFIG_MMC_SDHCI_SPEAR) += sdhci-spear.o
>  obj-$(CONFIG_MMC_WBSD)         += wbsd.o
>  obj-$(CONFIG_MMC_AU1X)         += au1xmmc.o
>  obj-$(CONFIG_MMC_MTK)          += mtk-sd.o
> +obj-$(CONFIG_MMC_OCTEON)       += octeon_mmc.o
>  obj-$(CONFIG_MMC_OMAP)         += omap.o
>  obj-$(CONFIG_MMC_OMAP_HS)      += omap_hsmmc.o
>  obj-$(CONFIG_MMC_ATMELMCI)     += atmel-mci.o
> diff --git a/drivers/mmc/host/octeon_mmc.c b/drivers/mmc/host/octeon_mmc.c
> new file mode 100644
> index 0000000..d2ef434
> --- /dev/null
> +++ b/drivers/mmc/host/octeon_mmc.c
> @@ -0,0 +1,1331 @@
> +/*
> + * Driver for MMC and SSD cards for Cavium OCTEON SOCs.
> + *
> + * This file is subject to the terms and conditions of the GNU General Public
> + * License.  See the file "COPYING" in the main directory of this archive
> + * for more details.
> + *
> + * Copyright (C) 2012-2016 Cavium Inc.
> + */
> +#include <linux/platform_device.h>
> +#include <linux/of_platform.h>
> +#include <linux/scatterlist.h>
> +#include <linux/interrupt.h>
> +#include <linux/blkdev.h>
> +#include <linux/device.h>
> +#include <linux/module.h>
> +#include <linux/delay.h>
> +#include <linux/init.h>
> +#include <linux/clk.h>
> +#include <linux/err.h>
> +#include <linux/io.h>
> +#include <linux/of.h>
> +
> +#include <linux/mmc/card.h>
> +#include <linux/mmc/host.h>
> +#include <linux/mmc/mmc.h>
> +#include <linux/mmc/sd.h>
> +#include <linux/mmc/slot-gpio.h>
> +#include <net/irda/parameters.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/regulator/consumer.h>
> +
> +#include <asm/byteorder.h>
> +#include <asm/octeon/octeon.h>

We shouldn't include SoC specific headers in a generic mmc driver.

If there are dependencies to perform SoC specific operations, then you
should use platform callbacks. Or better, if those operations can be
made through generic interfaces.

> +
> +#define DRV_NAME       "octeon_mmc"
> +
> +#define OCTEON_MAX_MMC                 4
> +
> +#define OCT_MIO_NDF_DMA_CFG            0x00
> +#define OCT_MIO_EMM_DMA_ADR            0x08
> +
> +#define OCT_MIO_EMM_CFG                        0x00
> +#define OCT_MIO_EMM_SWITCH             0x48
> +#define OCT_MIO_EMM_DMA                        0x50
> +#define OCT_MIO_EMM_CMD                        0x58
> +#define OCT_MIO_EMM_RSP_STS            0x60
> +#define OCT_MIO_EMM_RSP_LO             0x68
> +#define OCT_MIO_EMM_RSP_HI             0x70
> +#define OCT_MIO_EMM_INT                        0x78
> +#define OCT_MIO_EMM_INT_EN             0x80
> +#define OCT_MIO_EMM_WDOG               0x88
> +#define OCT_MIO_EMM_SAMPLE             0x90
> +#define OCT_MIO_EMM_STS_MASK           0x98
> +#define OCT_MIO_EMM_RCA                        0xa0
> +#define OCT_MIO_EMM_BUF_IDX            0xe0
> +#define OCT_MIO_EMM_BUF_DAT            0xe8
> +
> +#define CVMX_MIO_BOOT_CTL      CVMX_ADD_IO_SEG(0x00011800000000D0ull)
> +
> +struct octeon_mmc_host {
> +       void __iomem    *base;
> +       void __iomem    *ndf_base;
> +       u64     emm_cfg;
> +       u64     n_minus_one;  /* OCTEON II workaround location */
> +       int     last_slot;
> +
> +       struct semaphore mmc_serializer;
> +       struct mmc_request      *current_req;
> +       unsigned int            linear_buf_size;
> +       void                    *linear_buf;
> +       struct sg_mapping_iter smi;
> +       int sg_idx;
> +       bool dma_active;
> +
> +       struct platform_device  *pdev;
> +       struct gpio_desc *global_pwr_gpiod;
> +       bool dma_err_pending;
> +       bool need_bootbus_lock;
> +       bool big_dma_addr;
> +       bool need_irq_handler_lock;
> +       spinlock_t irq_handler_lock;
> +       bool has_ciu3;
> +
> +       struct octeon_mmc_slot  *slot[OCTEON_MAX_MMC];
> +};
> +
> +struct octeon_mmc_slot {
> +       struct mmc_host         *mmc;   /* slot-level mmc_core object */
> +       struct octeon_mmc_host  *host;  /* common hw for all 4 slots */
> +
> +       unsigned int            clock;
> +       unsigned int            sclock;
> +
> +       u64                     cached_switch;
> +       u64                     cached_rca;
> +
> +       unsigned int            cmd_cnt; /* sample delay */
> +       unsigned int            dat_cnt; /* sample delay */
> +
> +       int                     bus_width;
> +       int                     bus_id;
> +
> +       /* Legacy property - in future mmc->supply.vmmc should be used */
> +       struct gpio_desc        *pwr_gpiod;
> +};
> +
> +static int bb_size = 1 << 18;
> +module_param(bb_size, int, S_IRUGO);
> +MODULE_PARM_DESC(bb_size,
> +                "Size of DMA linearizing buffer (max transfer size).");
> +
> +static int ddr = 2;
> +module_param(ddr, int, S_IRUGO);
> +MODULE_PARM_DESC(ddr,
> +                "enable DoubleDataRate clocking: 0=no, 1=always, 2=at spi-max-frequency/2");

The module params here seem like a leftover from a debugging exercise.
Please remove them.

> +
> +static void octeon_mmc_acquire_bus(struct octeon_mmc_host *host)
> +{
> +       if (host->need_bootbus_lock) {
> +               down(&octeon_bootbus_sem);
> +               /* On cn70XX switch the mmc unit onto the bus. */
> +               if (OCTEON_IS_MODEL(OCTEON_CN70XX))

According to my upper comment about SoC specific code, please move
this code out of the driver.

You may use a DT compatible string to perform specific operations for
some versions of the IP/SoC, although not to call SoC specific code
directly.

This comment applies to other places for $subject patch as well,
although I am not going to comment on each of them. I leave that to
you to figure out.

> +                       writeq(0, (void __iomem *)CVMX_MIO_BOOT_CTL);
> +       } else {
> +               down(&host->mmc_serializer);
> +       }
> +}
> +

[...]

> +
> +/*
> + * The functions below are used for the EMMC-17978 workaround.
> + *
> + * Due to an imperfection in the design of the MMC bus hardware,
> + * the 2nd to last cache block of a DMA read must be locked into the L2 Cache.
> + * Otherwise, data corruption may occur.
> + */

Isn't these operations also depending on the SoC/Arch? If so, perhaps
you need a set of platform callbacks even for these.

> +
> +static inline void *phys_to_ptr(u64 address)
> +{
> +       return (void *)(address | (1ull<<63)); /* XKPHYS */
> +}
> +
> +/**
> + * Lock a single line into L2. The line is zeroed before locking
> + * to make sure no dram accesses are made.
> + *
> + * @addr   Physical address to lock
> + */
> +static void l2c_lock_line(u64 addr)
> +{
> +       char *addr_ptr = phys_to_ptr(addr);
> +       asm volatile (
> +               "cache 31, %[line]"     /* Unlock the line */
> +               :: [line] "m" (*addr_ptr));
> +}
> +
> +/**
> + * Locks a memory region in the L2 cache
> + *
> + * @start - start address to begin locking
> + * @len - length in bytes to lock
> + */
> +static void l2c_lock_mem_region(u64 start, u64 len)
> +{
> +       u64 end;
> +
> +       /* Round start/end to cache line boundaries */
> +       end = ALIGN(start + len - 1, CVMX_CACHE_LINE_SIZE);
> +       start = ALIGN(start, CVMX_CACHE_LINE_SIZE);
> +
> +       while (start <= end) {
> +               l2c_lock_line(start);
> +               start += CVMX_CACHE_LINE_SIZE;
> +       }
> +       asm volatile("sync");
> +}
> +
> +/**
> + * Unlock a single line in the L2 cache.
> + *
> + * @addr       Physical address to unlock
> + *
> + * Return Zero on success
> + */
> +static void l2c_unlock_line(u64 addr)
> +{
> +       char *addr_ptr = phys_to_ptr(addr);
> +       asm volatile (
> +               "cache 23, %[line]"     /* Unlock the line */
> +               :: [line] "m" (*addr_ptr));
> +}
> +
> +/**
> + * Unlock a memory region in the L2 cache
> + *
> + * @start - start address to unlock
> + * @len - length to unlock in bytes
> + */
> +static void l2c_unlock_mem_region(u64 start, u64 len)
> +{
> +       u64 end;
> +
> +       /* Round start/end to cache line boundaries */
> +       end = ALIGN(start + len - 1, CVMX_CACHE_LINE_SIZE);
> +       start = ALIGN(start, CVMX_CACHE_LINE_SIZE);
> +
> +       while (start <= end) {
> +               l2c_unlock_line(start);
> +               start += CVMX_CACHE_LINE_SIZE;
> +       }
> +}
> +

[...]

> +
> +static void octeon_mmc_dma_request(struct mmc_host *mmc,
> +                                  struct mmc_request *mrq)
> +{
> +       struct octeon_mmc_slot  *slot;
> +       struct octeon_mmc_host  *host;
> +       struct mmc_command *cmd;
> +       struct mmc_data *data;
> +       union cvmx_mio_emm_int emm_int;
> +       union cvmx_mio_emm_dma emm_dma;
> +       union cvmx_mio_ndf_dma_cfg dma_cfg;
> +
> +       cmd = mrq->cmd;
> +       if (mrq->data == NULL || mrq->data->sg == NULL || !mrq->data->sg_len ||
> +           mrq->stop == NULL || mrq->stop->opcode != MMC_STOP_TRANSMISSION) {
> +               dev_err(&mmc->card->dev,
> +                       "Error: octeon_mmc_dma_request no data\n");
> +               cmd->error = -EINVAL;
> +               if (mrq->done)
> +                       mrq->done(mrq);
> +               return;
> +       }
> +
> +       slot = mmc_priv(mmc);
> +       host = slot->host;
> +
> +       /* Only a single user of the bootbus at a time. */
> +       octeon_mmc_acquire_bus(host);
> +
> +       octeon_mmc_switch_to(slot);
> +
> +       data = mrq->data;
> +
> +       if (data->timeout_ns)
> +               writeq(octeon_mmc_timeout_to_wdog(slot, data->timeout_ns),
> +                      host->base + OCT_MIO_EMM_WDOG);
> +
> +       WARN_ON(host->current_req);
> +       host->current_req = mrq;
> +
> +       host->sg_idx = 0;
> +
> +       WARN_ON(data->blksz * data->blocks > host->linear_buf_size);
> +
> +       if ((data->flags & MMC_DATA_WRITE) && data->sg_len > 1) {
> +               size_t r = sg_copy_to_buffer(data->sg, data->sg_len,
> +                        host->linear_buf, data->blksz * data->blocks);
> +               WARN_ON(data->blksz * data->blocks != r);
> +       }
> +
> +       dma_cfg.u64 = 0;
> +       dma_cfg.s.en = 1;
> +       dma_cfg.s.rw = (data->flags & MMC_DATA_WRITE) ? 1 : 0;
> +#ifdef __LITTLE_ENDIAN
> +       dma_cfg.s.endian = 1;
> +#endif
> +       dma_cfg.s.size = ((data->blksz * data->blocks) / 8) - 1;
> +       if (!host->big_dma_addr) {
> +               if (data->sg_len > 1)
> +                       dma_cfg.s.adr = virt_to_phys(host->linear_buf);
> +               else
> +                       dma_cfg.s.adr = sg_phys(data->sg);
> +       }
> +       writeq(dma_cfg.u64, host->ndf_base + OCT_MIO_NDF_DMA_CFG);
> +       if (host->big_dma_addr) {
> +               u64 addr;
> +
> +               if (data->sg_len > 1)
> +                       addr = virt_to_phys(host->linear_buf);
> +               else
> +                       addr = sg_phys(data->sg);
> +               writeq(addr, host->ndf_base + OCT_MIO_EMM_DMA_ADR);
> +       }
> +
> +       emm_dma.u64 = 0;
> +       emm_dma.s.bus_id = slot->bus_id;
> +       emm_dma.s.dma_val = 1;
> +       emm_dma.s.sector = mmc_card_blockaddr(mmc->card) ? 1 : 0;
> +       emm_dma.s.rw = (data->flags & MMC_DATA_WRITE) ? 1 : 0;
> +       if (mmc_card_mmc(mmc->card) ||
> +           (mmc_card_sd(mmc->card) &&
> +               (mmc->card->scr.cmds & SD_SCR_CMD23_SUPPORT)))
> +               emm_dma.s.multi = 1;

Could you elaborate on exactly what you are doing here. I don't
understand why you need to check whether the card supports CMD23.

Moreover you must not access mmc->card unless you make sure there is a
valid pointer for it.

> +       emm_dma.s.block_cnt = data->blocks;
> +       emm_dma.s.card_addr = cmd->arg;
> +
> +       emm_int.u64 = 0;
> +       emm_int.s.dma_done = 1;
> +       emm_int.s.cmd_err = 1;
> +       emm_int.s.dma_err = 1;
> +       /* Clear the bit. */
> +       writeq(emm_int.u64, host->base + OCT_MIO_EMM_INT);
> +       if (!host->has_ciu3)
> +               writeq(emm_int.u64, host->base + OCT_MIO_EMM_INT_EN);
> +       host->dma_active = true;
> +
> +       if ((OCTEON_IS_MODEL(OCTEON_CN6XXX) ||
> +               OCTEON_IS_MODEL(OCTEON_CNF7XXX)) &&
> +           cmd->opcode == MMC_WRITE_MULTIPLE_BLOCK &&
> +           (data->blksz * data->blocks) > 1024) {
> +               host->n_minus_one = dma_cfg.s.adr +
> +                       (data->blksz * data->blocks) - 1024;
> +               l2c_lock_mem_region(host->n_minus_one, 512);
> +       }
> +
> +       if (mmc->card && mmc_card_sd(mmc->card))
> +               writeq(0x00b00000ull, host->base + OCT_MIO_EMM_STS_MASK);
> +       else
> +               writeq(0xe4f90080ull, host->base + OCT_MIO_EMM_STS_MASK);

Some explanation of what goes on here would be nice. You are writing
some magic mask depending on whether it SD or MMC.

Does that also mean this controller don't support SDIO? If so, you may
enable MMC_CAP2_NO_SDIO.

> +       writeq(emm_dma.u64, host->base + OCT_MIO_EMM_DMA);
> +}
> +
> +static void octeon_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
> +{
> +       struct octeon_mmc_slot  *slot;
> +       struct octeon_mmc_host  *host;
> +       struct mmc_command *cmd;
> +       union cvmx_mio_emm_int emm_int;
> +       union cvmx_mio_emm_cmd emm_cmd;
> +       struct octeon_mmc_cr_mods mods;
> +
> +       cmd = mrq->cmd;
> +
> +       if (cmd->opcode == MMC_READ_MULTIPLE_BLOCK ||
> +               cmd->opcode == MMC_WRITE_MULTIPLE_BLOCK) {

Instead of checking the opcode, perhaps you should check the number
blocks/bytes that is about to be transfers.

Or is there a particular reason to why multiblock transfers are required?

> +               octeon_mmc_dma_request(mmc, mrq);
> +               return;
> +       }
> +
> +       mods = octeon_mmc_get_cr_mods(cmd);
> +
> +       slot = mmc_priv(mmc);
> +       host = slot->host;

[...]

> +
> +static void octeon_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> +{
> +       struct octeon_mmc_slot  *slot;
> +       struct octeon_mmc_host  *host;
> +       int bus_width;
> +       int clock;
> +       bool ddr_clock;
> +       int hs_timing;
> +       int power_class = 10;
> +       int clk_period;
> +       int timeout = 2000;
> +       union cvmx_mio_emm_switch emm_switch;
> +       union cvmx_mio_emm_rsp_sts emm_sts;
> +
> +       slot = mmc_priv(mmc);
> +       host = slot->host;
> +
> +       /* Only a single user of the bootbus at a time. */
> +       octeon_mmc_acquire_bus(host);
> +
> +       octeon_mmc_switch_to(slot);
> +
> +       /*
> +        * Reset the chip on each power off
> +        */
> +       if (ios->power_mode == MMC_POWER_OFF) {
> +               octeon_mmc_reset_bus(slot);
> +               if (!IS_ERR(mmc->supply.vmmc))
> +                       regulator_disable(mmc->supply.vmmc);

You shouldn't access this regulator directly, as it's controlled by
the mmc core. Instead use mmc_regulator_set_ocr()

> +               else /* Legacy power GPIO */
> +                       gpiod_set_value_cansleep(slot->pwr_gpiod, 0);
> +       } else {
> +               if (!IS_ERR(mmc->supply.vmmc))
> +                       regulator_enable(mmc->supply.vmmc);

Similar comment as above. Use mmc_regulator_set_ocr().

> +               else /* Legacy power GPIO */
> +                       gpiod_set_value_cansleep(slot->pwr_gpiod, 1);
> +       }
> +
> +       switch (ios->bus_width) {
> +       case MMC_BUS_WIDTH_8:
> +               bus_width = 2;
> +               break;
> +       case MMC_BUS_WIDTH_4:
> +               bus_width = 1;
> +               break;
> +       case MMC_BUS_WIDTH_1:
> +               bus_width = 0;
> +               break;
> +       default:
> +               bus_width = 0;
> +               break;
> +       }

[...]

> +static const struct mmc_host_ops octeon_mmc_ops = {
> +       .request        = octeon_mmc_request,
> +       .set_ios        = octeon_mmc_set_ios,
> +       .get_ro         = mmc_gpio_get_ro,
> +       .get_cd         = mmc_gpio_get_cd,
> +};
> +
> +static void octeon_mmc_set_clock(struct octeon_mmc_slot *slot,
> +                                unsigned int clock)
> +{
> +       struct mmc_host *mmc = slot->mmc;
> +
> +       clock = min(clock, mmc->f_max);
> +       clock = max(clock, mmc->f_min);
> +       slot->clock = clock;
> +}
> +
> +static int octeon_mmc_initlowlevel(struct octeon_mmc_slot *slot,
> +                                  int bus_width)
> +{
> +       union cvmx_mio_emm_switch emm_switch;
> +       struct octeon_mmc_host *host = slot->host;
> +
> +       host->emm_cfg |= 1ull << slot->bus_id;
> +       writeq(host->emm_cfg, slot->host->base + OCT_MIO_EMM_CFG);
> +       octeon_mmc_set_clock(slot, 400000);
> +
> +       /* Program initial clock speed and power */
> +       emm_switch.u64 = 0;
> +       emm_switch.s.power_class = 10;
> +       emm_switch.s.clk_hi = (slot->sclock / slot->clock) / 2;
> +       emm_switch.s.clk_lo = (slot->sclock / slot->clock) / 2;
> +
> +       writeq(emm_switch.u64, host->base + OCT_MIO_EMM_SWITCH);
> +       emm_switch.s.bus_id = slot->bus_id;
> +       writeq(emm_switch.u64, host->base + OCT_MIO_EMM_SWITCH);
> +       slot->cached_switch = emm_switch.u64;
> +
> +       writeq(((u64)slot->clock * 850ull) / 1000ull,
> +              host->base + OCT_MIO_EMM_WDOG);
> +       writeq(0xe4f90080ull, host->base + OCT_MIO_EMM_STS_MASK);
> +       writeq(1, host->base + OCT_MIO_EMM_RCA);

Perhaps some comments explaining what goes on.

> +       return 0;
> +}
> +
> +static int octeon_mmc_slot_probe(struct platform_device *slot_pdev,
> +                                struct octeon_mmc_host *host)
> +{
> +       struct mmc_host *mmc;
> +       struct octeon_mmc_slot *slot;
> +       struct device *dev = &slot_pdev->dev;
> +       struct device_node *node = slot_pdev->dev.of_node;
> +       u32 id, bus_width, max_freq, cmd_skew, dat_skew;
> +       u64 clock_period;
> +       int ret;
> +
> +       ret = of_property_read_u32(node, "reg", &id);
> +       if (ret) {
> +               dev_err(dev, "Missing or invalid reg property on %s\n",
> +                       of_node_full_name(node));
> +               return ret;
> +       }
> +
> +       if (id >= OCTEON_MAX_MMC || host->slot[id]) {
> +               dev_err(dev, "Invalid reg property on %s\n",
> +                       of_node_full_name(node));
> +               return -EINVAL;
> +       }
> +
> +       mmc = mmc_alloc_host(sizeof(struct octeon_mmc_slot), dev);
> +       if (!mmc) {
> +               dev_err(dev, "alloc host failed\n");
> +               return -ENOMEM;
> +       }
> +
> +       slot = mmc_priv(mmc);
> +       slot->mmc = mmc;
> +       slot->host = host;
> +
> +       /*
> +        * The "cavium,bus-max-width" property is DEPRECATED and should
> +        * not be used. We handle it here to support older firmware.
> +        * Going forward, the standard "bus-width" property is used
> +        * instead of the Cavium-specific property.
> +        */

I think you should call mmc_of_parse() as it will parse for the common
mmc DT properties.

After that, you should parse for the deprecated mmc cavium DT
properties and when such is found, update the corresponding values for
bus width and max freq.

Perhaps you also need a default value for max freq, so you need to
check that as the final thing.

> +       ret = of_property_read_u32(node, "bus-width", &bus_width);
> +       if (ret) {
> +               /* Try legacy "cavium,bus-max-width" property. */
> +               ret = of_property_read_u32(node, "cavium,bus-max-width",
> +                                          &bus_width);
> +               if (ret) {
> +                       /* No bus width specified, use default. */
> +                       bus_width = 8;
> +                       dev_info(dev, "Default bus width %u used for slot %u\n",
> +                                bus_width, id);
> +               }
> +       }
> +
> +
> +       switch (bus_width) {
> +       case 1:
> +       case 4:
> +       case 8:
> +               break;
> +       default:
> +               dev_err(dev, "Invalid bus width for slot %u\n", id);
> +               ret = -EINVAL;
> +               goto err;
> +       }
> +
> +       /*
> +        * The "spi-max-frequency" property is DEPRECATED and should
> +        * not be used. We handle it here to support older firmware.
> +        * Going forward, the standard "max-frequency" property is
> +        * used instead.
> +        */
> +       ret = of_property_read_u32(node, "max-frequency", &max_freq);
> +       if (ret) {
> +               /* Try legacy "spi-max-frequency" property. */
> +               ret = of_property_read_u32(node, "spi-max-frequency",
> +                                          &max_freq);
> +               if (ret) {
> +                       /* No frequency properties found, use default. */
> +                       max_freq = 52000000;
> +                       dev_info(dev, "Default %u frequency used for slot %u\n",
> +                                id, max_freq);
> +               }
> +       }
> +
> +       /* Get regulators and the supported OCR mask */
> +       ret = mmc_regulator_get_supply(mmc);
> +       if (ret == -EPROBE_DEFER)
> +               goto err;
> +
> +       /* Alternatively a GPIO may be specified to control slot power */
> +       slot->pwr_gpiod = devm_gpiod_get_optional(dev, "power", GPIOD_OUT_LOW);

No, I am not happy with this as we discussed earlier. You need to
parse the DTB from SoC specifc code and manage the power GPIO from
there.

Ideally you should register the power GPIO as a GPIO regulator for the
cavium mmc slot device.

In that way you will get the calculated OCR mask just by calling
mmc_regulator_get_supply() and you don't need to use the GPIO API to
deal with powers.

> +
> +       /* Octeon specific DT properties */
> +       ret = of_property_read_u32(node, "cavium,cmd-clk-skew", &cmd_skew);
> +       if (ret)
> +               cmd_skew = 0;
> +
> +       ret = of_property_read_u32(node, "cavium,dat-clk-skew", &dat_skew);
> +       if (ret)
> +               dat_skew = 0;
> +
> +       /*
> +        * Set up host parameters.
> +        */
> +       mmc->ops = &octeon_mmc_ops;
> +       mmc->f_min = 400000;
> +       mmc->f_max = max_freq;
> +       mmc->caps = MMC_CAP_MMC_HIGHSPEED | MMC_CAP_SD_HIGHSPEED |
> +                   MMC_CAP_8_BIT_DATA | MMC_CAP_4_BIT_DATA |

The MMC_CAP_8_BIT_DATA and MMC_CAP_4_BIT_DATA is supposed to be
assigned depending on the configuration in DTS, not hardcoded like
this.

There's actually also DT bindings parses by mmc_of_parse() for
MMC_CAP_MMC_HIGHSPEED and MMC_CAP_SD_HIGHSPEED, although if you know
that your HW always supports these modes, it's fine to enabled them
like this.

> +                   MMC_CAP_ERASE;

To use MMC_CAP_ERASE, it's recomended to notify the mmc core about
your used request busy timeout.

So please assign the mmc->max_busy_timeout to its correct value.

> +       mmc->ocr_avail = MMC_VDD_27_28 | MMC_VDD_28_29 | MMC_VDD_29_30 |
> +                        MMC_VDD_30_31 | MMC_VDD_31_32 | MMC_VDD_32_33 |
> +                        MMC_VDD_33_34 | MMC_VDD_34_35 | MMC_VDD_35_36;

This you need to explain. I thought your power GPIO only supported on
and off. In other words it's a fixed regulator, no?

Anyway, when you converted to GPIO regulators you will get this mask
assigned by calling mmc_regulator_get_supply(), so you don't need any
of this at all.

> +
> +       /* post-sdk23 caps */
> +       mmc->caps |=
> +               ((mmc->f_max >= 12000000) * MMC_CAP_UHS_SDR12) |
> +               ((mmc->f_max >= 25000000) * MMC_CAP_UHS_SDR25) |
> +               ((mmc->f_max >= 50000000) * MMC_CAP_UHS_SDR50) |
> +               MMC_CAP_CMD23;

Supporting UHS mode requires you to be able to switch the I/O voltage
level from ~3.3 V to 1.8 V.

How do you manage that without implementing the following host ops?
->start_signal_voltage_switch()
->card_busy()

Also note that we have common mmc DT bindings for MMC_CAP_UHS*, which
is parsed via mmc_of_parse().

> +
> +       if ((!IS_ERR(mmc->supply.vmmc)) || (slot->pwr_gpiod))
> +               mmc->caps |= MMC_CAP_POWER_OFF_CARD;

This cap is used only for SDIO scenarios. I don't think you need it!?

> +
> +       /* "1.8v" capability is actually 1.8-or-3.3v */

Yes, there is a lacking capablity for eMMC 3.3 V, although I don't
think you need to care here...

> +       if (ddr)
> +               mmc->caps |= MMC_CAP_UHS_DDR50 | MMC_CAP_1_8V_DDR;

... I assume it's safe to enable MMC_CAP_1_8V_DDR as that applies to
eMMCs. Or you HW only supports 3.3V I/O voltage for eMMCs?

Although, because of the upper comment about UHS modes, you should
probably not enable MMC_CAP_UHS_DDR50 at all.

> +
> +       mmc->max_segs = 64;
> +       mmc->max_seg_size = host->linear_buf_size;
> +       mmc->max_req_size = host->linear_buf_size;
> +       mmc->max_blk_size = 512;
> +       mmc->max_blk_count = mmc->max_req_size / 512;
> +
> +       slot->clock = mmc->f_min;
> +       slot->sclock = octeon_get_io_clock_rate();
> +
> +       clock_period = 1000000000000ull / slot->sclock; /* period in pS */
> +       slot->cmd_cnt = (cmd_skew + clock_period / 2) / clock_period;
> +       slot->dat_cnt = (dat_skew + clock_period / 2) / clock_period;
> +
> +       slot->bus_width = bus_width;
> +       slot->bus_id = id;
> +       slot->cached_rca = 1;
> +
> +       /* Only a single user of the bootbus at a time. */
> +       octeon_mmc_acquire_bus(host);
> +       host->slot[id] = slot;
> +
> +       octeon_mmc_switch_to(slot);
> +       /* Initialize MMC Block. */
> +       octeon_mmc_initlowlevel(slot, bus_width);
> +
> +       octeon_mmc_release_bus(host);
> +
> +       ret = mmc_add_host(mmc);
> +       if (ret) {
> +               dev_err(dev, "mmc_add_host() returned %d\n", ret);
> +               goto err;
> +       }
> +
> +       return 0;
> +
> +err:
> +       slot->host->slot[id] = NULL;
> +
> +       gpiod_set_value_cansleep(slot->pwr_gpiod, 0);
> +
> +       mmc_free_host(slot->mmc);
> +       return ret;
> +}
> +
> +static int octeon_mmc_slot_remove(struct octeon_mmc_slot *slot)
> +{
> +       mmc_remove_host(slot->mmc);
> +
> +       slot->host->slot[slot->bus_id] = NULL;
> +
> +       gpiod_set_value_cansleep(slot->pwr_gpiod, 0);
> +
> +       mmc_free_host(slot->mmc);
> +
> +       return 0;
> +}
> +
> +static int octeon_mmc_probe(struct platform_device *pdev)
> +{
> +       struct octeon_mmc_host *host;
> +       struct resource *res;
> +       void __iomem *base;
> +       int mmc_irq[9];
> +       int i;
> +       int ret = 0;
> +       struct device_node *node = pdev->dev.of_node;
> +       struct device_node *cn;
> +       bool cn78xx_style;
> +       u64 t;
> +
> +       host = devm_kzalloc(&pdev->dev, sizeof(*host), GFP_KERNEL);
> +       if (!host) {
> +               dev_err(&pdev->dev, "devm_kzalloc failed\n");
> +               return -ENOMEM;
> +       }
> +
> +       spin_lock_init(&host->irq_handler_lock);
> +       sema_init(&host->mmc_serializer, 1);
> +
> +       cn78xx_style = of_device_is_compatible(node, "cavium,octeon-7890-mmc");
> +       if (cn78xx_style) {
> +               host->need_bootbus_lock = false;
> +               host->big_dma_addr = true;
> +               host->need_irq_handler_lock = true;
> +               host->has_ciu3 = true;
> +               /*
> +                * First seven are the EMM_INT bits 0..6, then two for
> +                * the EMM_DMA_INT bits
> +                */
> +               for (i = 0; i < 9; i++) {
> +                       mmc_irq[i] = platform_get_irq(pdev, i);
> +                       if (mmc_irq[i] < 0)
> +                               return mmc_irq[i];
> +
> +                       /* work around legacy u-boot device trees */
> +                       irq_set_irq_type(mmc_irq[i], IRQ_TYPE_EDGE_RISING);
> +               }
> +       } else {
> +               host->need_bootbus_lock = true;
> +               host->big_dma_addr = false;
> +               host->need_irq_handler_lock = false;
> +               host->has_ciu3 = false;
> +               /* First one is EMM second NDF_DMA */
> +               for (i = 0; i < 2; i++) {
> +                       mmc_irq[i] = platform_get_irq(pdev, i);
> +                       if (mmc_irq[i] < 0)
> +                               return mmc_irq[i];
> +               }
> +       }
> +       host->last_slot = -1;
> +
> +       if (bb_size < 512 || bb_size >= (1 << 24))
> +               bb_size = 1 << 18;
> +       host->linear_buf_size = bb_size;
> +       host->linear_buf = devm_kzalloc(&pdev->dev, host->linear_buf_size,
> +                                       GFP_KERNEL);
> +
> +       if (!host->linear_buf) {
> +               dev_err(&pdev->dev, "devm_kzalloc failed\n");
> +               return -ENOMEM;
> +       }
> +
> +       host->pdev = pdev;
> +
> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +       if (!res) {
> +               dev_err(&pdev->dev, "Platform resource[0] is missing\n");
> +               return -ENXIO;
> +       }
> +       base = devm_ioremap_resource(&pdev->dev, res);
> +       if (IS_ERR(base))
> +               return PTR_ERR(base);
> +       host->base = (void __iomem *)base;
> +
> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> +       if (!res) {
> +               dev_err(&pdev->dev, "Platform resource[1] is missing\n");
> +               return -EINVAL;
> +       }
> +       base = devm_ioremap_resource(&pdev->dev, res);
> +       if (IS_ERR(base))
> +               return PTR_ERR(base);
> +       host->ndf_base = (void __iomem *)base;
> +
> +       /*
> +        * Clear out any pending interrupts that may be left over from
> +        * bootloader.
> +        */
> +       t = readq(host->base + OCT_MIO_EMM_INT);
> +       writeq(t, host->base + OCT_MIO_EMM_INT);
> +       if (cn78xx_style) {
> +               /* Only CMD_DONE, DMA_DONE, CMD_ERR, DMA_ERR */
> +               for (i = 1; i <= 4; i++) {
> +                       ret = devm_request_irq(&pdev->dev, mmc_irq[i],
> +                                              octeon_mmc_interrupt,
> +                                              0, DRV_NAME, host);
> +                       if (ret < 0) {
> +                               dev_err(&pdev->dev, "Error: devm_request_irq %d\n",
> +                                       mmc_irq[i]);
> +                               return ret;
> +                       }
> +               }
> +       } else {
> +               ret = devm_request_irq(&pdev->dev, mmc_irq[0],
> +                                      octeon_mmc_interrupt, 0, DRV_NAME, host);
> +               if (ret < 0) {
> +                       dev_err(&pdev->dev, "Error: devm_request_irq %d\n",
> +                               mmc_irq[0]);
> +                       return ret;
> +               }
> +       }
> +
> +       host->global_pwr_gpiod = devm_gpiod_get_optional(&pdev->dev, "power",
> +                                                               GPIOD_OUT_HIGH);

Again, please don't use power GPIOS in the driver. Ideally you should
register the power GPIO as a GPIO regulator for the cavium mmc device.

Although I wonder what this "global" power GPIO actually is powering?

Perhaps it is just needed to allow the child node slots to power the
cards? If so, it should be registered as a supply (parent) for those
GPIO regulators instead and then you don't need to deal with it at all
in the driver...

> +       if (IS_ERR(host->global_pwr_gpiod)) {
> +               dev_err(&host->pdev->dev, "Invalid POWER GPIO\n");
> +               return PTR_ERR(host->global_pwr_gpiod);
> +       }
> +
> +       platform_set_drvdata(pdev, host);
> +
> +       for_each_child_of_node(node, cn) {
> +               struct platform_device *slot_pdev;
> +
> +               slot_pdev = of_platform_device_create(cn, NULL, &pdev->dev);
> +               ret = octeon_mmc_slot_probe(slot_pdev, host);
> +               if (ret) {
> +                       dev_err(&host->pdev->dev, "Error populating slots\n");
> +                       gpiod_set_value_cansleep(host->global_pwr_gpiod, 0);
> +                       return ret;
> +               }
> +       }
> +
> +       return 0;
> +}
> +

[...]

Kind regards
Uffe




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