() On Thu, 14 Apr 2022 at 05:45, Tony Huang <tonyhuang.sunplus@xxxxxxxxx> wrote: > > Addressed comments from kernel test robot. > Remove unused vairable. Add previous prototype. > Addressed make error and warning in kernel 5.18-rc1. I think a new driver deserves some information about the HW in the commit message. We don't need details, but some top level information would be good. Can you please add this? > > Signed-off-by: Tony Huang <tonyhuang.sunplus@xxxxxxxxx> > --- > Changes in v5: > - Addressed comments from Krzysztof. > - Remove the relevant sdcard code. > - Submit the emmc code only. > > Changes in v6: > - Addressed comments from Arnd. > - Use SYSTEM_SLEEP_PM_OPS instead of SET_SYSTEM_SLEEP_PM_OPS. > - Use RUNTIME_PM_OPS instead of SET_RUNTIME_PM_OPS. > - Remove #ifdef check. > - Fixed mutex lock and unlock imbalance issue. > > Changes in v7: > - Addressed comments from kernel test robot. > - Remove unused vairable. > - Add previous prototype. > - Addressed make error and warning in kernel 5.18-rc1. > > MAINTAINERS | 1 + > drivers/mmc/host/Kconfig | 9 + > drivers/mmc/host/Makefile | 1 + > drivers/mmc/host/sunplus-mmc.c | 1183 ++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 1194 insertions(+) > create mode 100644 drivers/mmc/host/sunplus-mmc.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index cdd809a..2439234 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -18874,6 +18874,7 @@ M: Tony Huang <tonyhuang.sunplus@xxxxxxxxx> > M: Li-hao Kuo <lhjeff911@xxxxxxxxx> > S: Maintained > F: Documentation/devicetree/bindings/mmc/sunplus,mmc.yaml > +F: drivers/mmc/host/sunplus-mmc.c > > SUNPLUS OCOTP DRIVER > M: Vincent Shih <vincent.sunplus@xxxxxxxxx> > diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig > index af6c3c3..d99ee3b 100644 > --- a/drivers/mmc/host/Kconfig > +++ b/drivers/mmc/host/Kconfig > @@ -14,6 +14,15 @@ config MMC_DEBUG > added host drivers please don't invent their private macro for > debugging. > > +config MMC_SUNPLUS > + tristate "Sunplus SP7021 MMC Controller" > + depends on ARCH_SUNPLUS || COMPILE_TEST > + help > + If you say yes here, you will get support for eMMC host interface > + on Sunplus SoCs. > + > + If unsure, say N > + > config MMC_ARMMMCI > tristate "ARM AMBA Multimedia Card Interface support" > depends on ARM_AMBA > diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile > index 4e4ceb3..ba0c6d0 100644 > --- a/drivers/mmc/host/Makefile > +++ b/drivers/mmc/host/Makefile > @@ -97,6 +97,7 @@ obj-$(CONFIG_MMC_SDHCI_MICROCHIP_PIC32) += sdhci-pic32.o > obj-$(CONFIG_MMC_SDHCI_BRCMSTB) += sdhci-brcmstb.o > obj-$(CONFIG_MMC_SDHCI_OMAP) += sdhci-omap.o > obj-$(CONFIG_MMC_SDHCI_SPRD) += sdhci-sprd.o > +obj-$(CONFIG_MMC_SUNPLUS) += sunplus-mmc.o > obj-$(CONFIG_MMC_CQHCI) += cqhci.o > cqhci-y += cqhci-core.o > cqhci-$(CONFIG_MMC_CRYPTO) += cqhci-crypto.o > diff --git a/drivers/mmc/host/sunplus-mmc.c b/drivers/mmc/host/sunplus-mmc.c > new file mode 100644 > index 0000000..9183437 > --- /dev/null > +++ b/drivers/mmc/host/sunplus-mmc.c > @@ -0,0 +1,1183 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Copyright (c) Sunplus Inc. > + * Author: Tony Huang <tonyhuang.sunplus@xxxxxxxxx> > + * Author: Li-hao Kuo <lhjeff911@xxxxxxxxx> > + */ > + > +#include <linux/bitfield.h> > +#include <linux/clk.h> > +#include <linux/delay.h> > +#include <linux/dma-mapping.h> > +#include <linux/interrupt.h> > +#include <linux/mmc/core.h> > +#include <linux/mmc/host.h> > +#include <linux/mmc/mmc.h> > +#include <linux/mmc/sdio.h> > +#include <linux/mmc/slot-gpio.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/of_device.h> > +#include <linux/platform_device.h> > +#include <linux/pm.h> > +#include <linux/pm_runtime.h> > +#include <linux/reset.h> > + > +#define SPMMC_MIN_CLK 400000 > +#define SPMMC_MAX_CLK 52000000 > +#define SPMMC_MAX_BLK_COUNT 65536 > +#define SPMMC_MAX_TUNABLE_DLY 7 > + > +#define SPMMC_CARD_MEDIATYPE_SRCDST_REG 0x0000 > +#define SPMMC_MEDIA_TYPE GENMASK(2, 0) > +#define SPMMC_DMA_SOURCE GENMASK(6, 4) > +#define SPMMC_DMA_DESTINATION GENMASK(10, 8) > +#define SPMMC_MEDIA_NONE 0 > +#define SPMMC_MEDIA_SD 6 > +#define SPMMC_MEDIA_MS 7 > + > +#define SPMMC_SDRAM_SECTOR_0_SIZE_REG 0x0008 > +#define SPMMC_DMA_BASE_ADDR_REG 0x000C > +#define SPMMC_HW_DMA_CTRL_REG 0x0010 > +#define SPMMC_HW_DMA_RST BIT(9) > +#define SPMMC_DMAIDLE BIT(10) > + > +#define SPMMC_MAX_DMA_MEMORY_SECTORS 8 > + > +#define SPMMC_SDRAM_SECTOR_1_ADDR_REG 0x0018 > + > +#define SPMMC_SD_INT_REG 0x0088 > +#define SPMMC_SDINT_SDCMPEN BIT(0) > +#define SPMMC_SDINT_SDCMP BIT(1) > +#define SPMMC_SDINT_SDCMPCLR BIT(2) > +#define SPMMC_SDINT_SDIOEN BIT(3) > +#define SPMMC_SDINT_SDIO BIT(4) > +#define SPMMC_SDINT_SDIOCLR BIT(5) > + > +#define SPMMC_SD_PAGE_NUM_REG 0x008C > + > +#define SPMMC_SD_CONFIG0_REG 0x0090 > +#define SPMMC_SD_PIO_MODE BIT(0) > +#define SPMMC_SD_DDR_MODE BIT(1) > +#define SPMMC_SD_LEN_MODE BIT(2) > +#define SPMMC_SD_TRANS_MODE GENMASK(5, 4) > +#define SPMMC_SD_AUTO_RESPONSE BIT(6) > +#define SPMMC_SD_CMD_DUMMY BIT(7) > +#define SPMMC_SD_RSP_CHK_EN BIT(8) > +#define SPMMC_SDIO_MODE BIT(9) > +#define SPMMC_SD_MMC_MODE BIT(10) > +#define SPMMC_SD_DATA_WD BIT(11) > +#define SPMMC_RX4_EN BIT(14) > +#define SPMMC_SD_RSP_TYPE BIT(15) > +#define SPMMC_MMC8_EN BIT(18) > +#define SPMMC_CLOCK_DIVISION GENMASK(31, 20) > + > +#define SPMMC_SDIO_CTRL_REG 0x0094 > +#define SPMMC_INT_MULTI_TRIG BIT(6) > + > +#define SPMMC_SD_RST_REG 0x0098 > +#define SPMMC_SD_CTRL_REG 0x009C > +#define SPMMC_NEW_COMMAND_TRIGGER BIT(0) > +#define SPMMC_DUMMY_CLOCK_TRIGGER BIT(1) > + > +#define SPMMC_SD_STATUS_REG 0x00A0 > +#define SPMMC_SDSTATUS_DUMMY_READY BIT(0) > +#define SPMMC_SDSTATUS_RSP_BUF_FULL BIT(1) > +#define SPMMC_SDSTATUS_TX_DATA_BUF_EMPTY BIT(2) > +#define SPMMC_SDSTATUS_RX_DATA_BUF_FULL BIT(3) > +#define SPMMC_SDSTATUS_CMD_PIN_STATUS BIT(4) > +#define SPMMC_SDSTATUS_DAT0_PIN_STATUS BIT(5) > +#define SPMMC_SDSTATUS_RSP_TIMEOUT BIT(6) > +#define SPMMC_SDSTATUS_CARD_CRC_CHECK_TIMEOUT BIT(7) > +#define SPMMC_SDSTATUS_STB_TIMEOUT BIT(8) > +#define SPMMC_SDSTATUS_RSP_CRC7_ERROR BIT(9) > +#define SPMMC_SDSTATUS_CRC_TOKEN_CHECK_ERROR BIT(10) > +#define SPMMC_SDSTATUS_RDATA_CRC16_ERROR BIT(11) > +#define SPMMC_SDSTATUS_SUSPEND_STATE_READY BIT(12) > +#define SPMMC_SDSTATUS_BUSY_CYCLE BIT(13) > +#define SPMMC_SDSTATUS_DAT1_PIN_STATUS BIT(14) > +#define SPMMC_SDSTATUS_SD_SENSE_STATUS BIT(15) > +#define SPMMC_SDSTATUS_BOOT_ACK_TIMEOUT BIT(16) > +#define SPMMC_SDSTATUS_BOOT_DATA_TIMEOUT BIT(17) > +#define SPMMC_SDSTATUS_BOOT_ACK_ERROR BIT(18) > + > +#define SPMMC_SD_STATE_REG 0x00A4 > +#define SPMMC_CRCTOKEN_CHECK_RESULT GENMASK(6, 4) > +#define SPMMC_SDSTATE_ERROR BIT(13) > +#define SPMMC_SDSTATE_FINISH BIT(14) > + > +#define SPMMC_SD_HW_STATE_REG 0x00A8 > +#define SPMMC_SD_BLOCKSIZE_REG 0x00AC > + > +#define SPMMC_SD_CONFIG1_REG 0x00B0 > +#define SPMMC_TX_DUMMY_NUM GENMASK(8, 0) > +#define SPMMC_SD_HIGH_SPEED_EN BIT(31) > + > +#define SPMMC_SD_TIMING_CONFIG0_REG 0x00B4 > +#define SPMMC_SD_CLOCK_DELAY GENMASK(2, 0) > +#define SPMMC_SD_WRITE_DATA_DELAY GENMASK(6, 4) > +#define SPMMC_SD_WRITE_COMMAND_DELAY GENMASK(10, 8) > +#define SPMMC_SD_READ_RESPONSE_DELAY GENMASK(14, 12) > +#define SPMMC_SD_READ_DATA_DELAY GENMASK(18, 16) > +#define SPMMC_SD_READ_CRC_DELAY GENMASK(22, 20) > + > +#define SPMMC_SD_PIODATATX_REG 0x00BC > +#define SPMMC_SD_PIODATARX_REG 0x00C0 > +#define SPMMC_SD_CMDBUF0_3_REG 0x00C4 > +#define SPMMC_SD_CMDBUF4_REG 0x00C8 > +#define SPMMC_SD_RSPBUF0_3_REG 0x00CC > +#define SPMMC_SD_RSPBUF4_5_REG 0x00D0 > + > +#define SPMMC_MAX_RETRIES (8 * 8) > + > +struct spmmc_tuning_info { > + int enable_tuning; > + int need_tuning; > + int retried; /* how many times has been retried */ > + u32 rd_crc_dly:3; > + u32 rd_dat_dly:3; > + u32 rd_rsp_dly:3; > + u32 wr_cmd_dly:3; > + u32 wr_dat_dly:3; > + u32 clk_dly:3; > +}; > + > +static const u8 tuning_blk_pattern_4bit[] = { > + 0xff, 0x0f, 0xff, 0x00, 0xff, 0xcc, 0xc3, 0xcc, > + 0xc3, 0x3c, 0xcc, 0xff, 0xfe, 0xff, 0xfe, 0xef, > + 0xff, 0xdf, 0xff, 0xdd, 0xff, 0xfb, 0xff, 0xfb, > + 0xbf, 0xff, 0x7f, 0xff, 0x77, 0xf7, 0xbd, 0xef, > + 0xff, 0xf0, 0xff, 0xf0, 0x0f, 0xfc, 0xcc, 0x3c, > + 0xcc, 0x33, 0xcc, 0xcf, 0xff, 0xef, 0xff, 0xee, > + 0xff, 0xfd, 0xff, 0xfd, 0xdf, 0xff, 0xbf, 0xff, > + 0xbb, 0xff, 0xf7, 0xff, 0xf7, 0x7f, 0x7b, 0xde, > +}; > + > +static const u8 tuning_blk_pattern_8bit[] = { > + 0xff, 0xff, 0x00, 0xff, 0xff, 0xff, 0x00, 0x00, > + 0xff, 0xff, 0xcc, 0xcc, 0xcc, 0x33, 0xcc, 0xcc, > + 0xcc, 0x33, 0x33, 0xcc, 0xcc, 0xcc, 0xff, 0xff, > + 0xff, 0xee, 0xff, 0xff, 0xff, 0xee, 0xee, 0xff, > + 0xff, 0xff, 0xdd, 0xff, 0xff, 0xff, 0xdd, 0xdd, > + 0xff, 0xff, 0xff, 0xbb, 0xff, 0xff, 0xff, 0xbb, > + 0xbb, 0xff, 0xff, 0xff, 0x77, 0xff, 0xff, 0xff, > + 0x77, 0x77, 0xff, 0x77, 0xbb, 0xdd, 0xee, 0xff, > + 0xff, 0xff, 0xff, 0x00, 0xff, 0xff, 0xff, 0x00, > + 0x00, 0xff, 0xff, 0xcc, 0xcc, 0xcc, 0x33, 0xcc, > + 0xcc, 0xcc, 0x33, 0x33, 0xcc, 0xcc, 0xcc, 0xff, > + 0xff, 0xff, 0xee, 0xff, 0xff, 0xff, 0xee, 0xee, > + 0xff, 0xff, 0xff, 0xdd, 0xff, 0xff, 0xff, 0xdd, > + 0xdd, 0xff, 0xff, 0xff, 0xbb, 0xff, 0xff, 0xff, > + 0xbb, 0xbb, 0xff, 0xff, 0xff, 0x77, 0xff, 0xff, > + 0xff, 0x77, 0x77, 0xff, 0x77, 0xbb, 0xdd, 0xee, > +}; The tuning pattern should not be needed in a host driver. Please drop them. > + > +enum { > + SPMMC_DMA_MODE = 0, > + SPMMC_PIO_MODE = 1, Looks like a bool is better than enum with two values. Please convert. > +}; > + > +struct spmmc_host { > + void __iomem *base; > + struct clk *clk; > + struct reset_control *rstc; > + spinlock_t lock; /* Prevent races with irq handler */ > + struct mutex mrq_lock; /* protect spmmc_set_ios() context and spmmc_request() */ > + /* tasklet used to handle error then finish the request */ > + struct tasklet_struct tsklet_finish_req; We are moving away from tasklets for mmc hosts. Please use a threaded IRQ handler instead. > + struct mmc_host *mmc; > + struct mmc_request *mrq; /* current mrq */ > + int irq; > + int use_int; /* should raise irq when done? */ > + int power_state; /* current power state: off/up/on */ > + int ddr_enabled; > + int signal_voltage; > + int dmapio_mode; > + /* > + * for purpose of reducing context switch, only when transfer data that > + * length is greater than `dma_int_threshold' should use interrupt > + */ > + int dma_int_threshold; > + struct sg_mapping_iter sg_miter; /* for pio mode to access sglist */ > + int dma_use_int; /* should raise irq when dma done */ > + struct spmmc_tuning_info tuning_info; > +}; > + > +/* > + * wait for transaction done, return -1 if error. > + */ > +static inline int spmmc_wait_finish(struct spmmc_host *host) > +{ > + /* Wait for transaction finish */ > + unsigned long timeout = jiffies + msecs_to_jiffies(5000); Is there a specific reason why you have chosen 5000ms for this timeout? At least add a define for it. > + > + while (!time_after(jiffies, timeout)) { > + if (readl(host->base + SPMMC_SD_STATE_REG) & SPMMC_SDSTATE_FINISH) > + return 0; > + if (readl(host->base + SPMMC_SD_STATE_REG) & SPMMC_SDSTATE_ERROR) > + return -EIO; > + } Please replace this with readl_poll_timeout() - or with one of its variants. > + > + return -ETIMEDOUT; > +} > + > +static inline int spmmc_wait_sdstatus(struct spmmc_host *host, unsigned int status_bit) > +{ > + unsigned long timeout = jiffies + msecs_to_jiffies(5000); Why 5000ms? > + > + while (!time_after(jiffies, timeout)) { > + if (readl(host->base + SPMMC_SD_STATUS_REG) & status_bit) > + return 0; > + if (readl(host->base + SPMMC_SD_STATE_REG) & SPMMC_SDSTATE_ERROR) > + return -EIO; > + } readl_poll_timeout() > + > + return -ETIMEDOUT; > +} > + > +#define spmmc_wait_rspbuf_full(host) spmmc_wait_sdstatus(host, SPMMC_SDSTATUS_RSP_BUF_FULL) > +#define spmmc_wait_rxbuf_full(host) spmmc_wait_sdstatus(host, SPMMC_SDSTATUS_RX_DATA_BUF_FULL) > +#define spmmc_wait_txbuf_empty(host) spmmc_wait_sdstatus(host, SPMMC_SDSTATUS_TX_DATA_BUF_EMPTY) > + > +static void spmmc_get_rsp(struct spmmc_host *host, struct mmc_command *cmd) > +{ > + u32 value0_3, value4_5; > + > + if (unlikely(!(cmd->flags & MMC_RSP_PRESENT))) > + return; > + if (unlikely(cmd->flags & MMC_RSP_136)) { I think the two "unlikely" here are questionable. Can you explain why they are improving things - or let's just drop them!? > + if (spmmc_wait_rspbuf_full(host)) > + return; > + value0_3 = readl(host->base + SPMMC_SD_RSPBUF0_3_REG); > + value4_5 = readl(host->base + SPMMC_SD_RSPBUF4_5_REG) & 0xffff; > + cmd->resp[0] = (value0_3 << 8) | (value4_5 >> 8); > + cmd->resp[1] = value4_5 << 24; > + value0_3 = readl(host->base + SPMMC_SD_RSPBUF0_3_REG); > + value4_5 = readl(host->base + SPMMC_SD_RSPBUF4_5_REG) & 0xffff; > + cmd->resp[1] |= value0_3 >> 8; > + cmd->resp[2] = value0_3 << 24; > + cmd->resp[2] |= value4_5 << 8; > + value0_3 = readl(host->base + SPMMC_SD_RSPBUF0_3_REG); > + value4_5 = readl(host->base + SPMMC_SD_RSPBUF4_5_REG) & 0xffff; > + cmd->resp[2] |= value0_3 >> 24; > + cmd->resp[3] = value0_3 << 8; > + cmd->resp[3] |= value4_5 >> 8; > + } else { > + if (spmmc_wait_rspbuf_full(host)) > + return; > + value0_3 = readl(host->base + SPMMC_SD_RSPBUF0_3_REG); > + value4_5 = readl(host->base + SPMMC_SD_RSPBUF4_5_REG) & 0xffff; > + cmd->resp[0] = (value0_3 << 8) | (value4_5 >> 8); > + cmd->resp[1] = value4_5 << 24; > + } > +} > + > +static void spmmc_set_bus_clk(struct spmmc_host *host, int clk) > +{ > + unsigned int clkdiv; > + int f_min = host->mmc->f_min; > + int f_max = host->mmc->f_max; > + u32 value = readl(host->base + SPMMC_SD_CONFIG0_REG); > + > + if (clk < f_min) > + clk = f_min; > + if (clk > f_max) > + clk = f_max; > + > + clkdiv = (clk_get_rate(host->clk) + clk) / clk - 1; > + if (clkdiv > 0xfff) > + clkdiv = 0xfff; > + > + value |= FIELD_PREP(SPMMC_CLOCK_DIVISION, clkdiv); > + writel(value, host->base + SPMMC_SD_CONFIG0_REG); > + > + /* > + * In order to reduce the frequency of context switch, > + * if it is high speed or upper, we do not use interrupt > + * when send a command that without data transferring. > + */ This seems questionable to me. Not using IRQs, means that we will do polling instead, right? Polling means hogging the CPU, which certainly should be avoided, unless it's necessary. Therefore, I suggest you drop this feature for now. Let's instead consider this as a future improvement that can be done on top of the initial support - if it can be proven to be better. > + if (clk > 25000000) > + host->use_int = 0; > + else > + host->use_int = 1; > +} [...] > +/* > + * select the working mode of controller: sd/sdio/emmc > + */ > +static void spmmc_select_mode(struct spmmc_host *host) I guess you intend to extend this to be able to set the SDIO mode too, as a patch on top? In any case, I suggest you rename this function to spmmc_set_ sdmmc_mode() for now, to better reflect what the function does. Then when adding SDIO support we can change this, if needed. > +{ > + u32 value = readl(host->base + SPMMC_SD_CONFIG0_REG); > + > + value |= SPMMC_SD_MMC_MODE; > + value &= ~SPMMC_SDIO_MODE; > + writel(value, host->base + SPMMC_SD_CONFIG0_REG); > +} > + > +static void spmmc_sw_reset(struct spmmc_host *host) > +{ > + u32 value; > + > + /* > + * Must reset dma operation first, or it will > + * be stuck on sd_state == 0x1c00 because of > + * a controller software reset bug > + */ > + value = readl(host->base + SPMMC_HW_DMA_CTRL_REG); > + value |= SPMMC_DMAIDLE; > + writel(value, host->base + SPMMC_HW_DMA_CTRL_REG); > + value &= ~SPMMC_DMAIDLE; > + writel(value, host->base + SPMMC_HW_DMA_CTRL_REG); > + value = readl(host->base + SPMMC_HW_DMA_CTRL_REG); > + value |= SPMMC_HW_DMA_RST; > + writel(value, host->base + SPMMC_HW_DMA_CTRL_REG); > + writel(0x7, host->base + SPMMC_SD_RST_REG); > + while (readl(host->base + SPMMC_SD_HW_STATE_REG) & BIT(6)) > + ; White space. > +} > + > +static void spmmc_prepare_cmd(struct spmmc_host *host, struct mmc_command *cmd) > +{ > + u32 value; > + > + /* add start bit, according to spec, command format */ > + value = ((cmd->opcode | 0x40) << 24) | (cmd->arg >> 8); > + writel(value, host->base + SPMMC_SD_CMDBUF0_3_REG); > + writeb(cmd->arg & 0xff, host->base + SPMMC_SD_CMDBUF4_REG); > + > + /* disable interrupt if needed */ > + value = readl(host->base + SPMMC_SD_INT_REG); > + value |= SPMMC_SDINT_SDCMPCLR; /* sd_cmp_clr */ The comment seems a bit superfluous, please drop it. > + if (likely(!host->use_int || cmd->flags & MMC_RSP_136)) > + value &= ~SPMMC_SDINT_SDCMPEN; /* sdcmpen */ Ditto. > + else > + value |= SPMMC_SDINT_SDCMPEN; > + > + writel(value, host->base + SPMMC_SD_INT_REG); > + > + value = readl(host->base + SPMMC_SD_CONFIG0_REG); > + value &= ~SPMMC_SD_TRANS_MODE; /* sd_trans_mode */ Ditto. > + value |= SPMMC_SD_CMD_DUMMY; /* sdcmddummy */ Ditto. Or, perhaps this actually deserves a comment. What is this bit for? > + if (likely(cmd->flags & MMC_RSP_PRESENT)) { Again, I think using "likely" here is questionable. Please explain how it helps - or drop it. > + value |= SPMMC_SD_AUTO_RESPONSE; /* sdautorsp */ > + } else { > + value &= ~SPMMC_SD_AUTO_RESPONSE; > + writel(value, host->base + SPMMC_SD_CONFIG0_REG); > + > + return; > + } > + /* > + * Currently, host is not capable of checking R2's CRC7, > + * thus, enable crc7 check only for 48 bit response commands > + */ > + if (likely(cmd->flags & MMC_RSP_CRC && !(cmd->flags & MMC_RSP_136))) Ditto. > + value |= SPMMC_SD_RSP_CHK_EN; /* sdrspchk_en */ Here's another comment that doesn't add anything. Please drop this and all following similar types of comments. I will stop commenting on them from now on. I will also stop commenting on "likely/unlikely", as the similar comments that have already been made, apply to the rest of the code too. > + else > + value &= ~SPMMC_SD_RSP_CHK_EN; > + > + if (unlikely(cmd->flags & MMC_RSP_136)) > + value |= SPMMC_SD_RSP_TYPE; /* sdrsptype */ > + else > + value &= ~SPMMC_SD_RSP_TYPE; > + writel(value, host->base + SPMMC_SD_CONFIG0_REG); > +} > + > +static void spmmc_prepare_data(struct spmmc_host *host, struct mmc_data *data) > +{ > + u32 value, srcdst; > + > + writel(data->blocks - 1, host->base + SPMMC_SD_PAGE_NUM_REG); > + writel(data->blksz - 1, host->base + SPMMC_SD_BLOCKSIZE_REG); > + value = readl(host->base + SPMMC_SD_CONFIG0_REG); > + if (data->flags & MMC_DATA_READ) { > + value |= FIELD_PREP(SPMMC_SD_TRANS_MODE, 2); /* sd_trans_mode */ > + value &= ~SPMMC_SD_AUTO_RESPONSE; /* sdautorsp */ > + value &= ~SPMMC_SD_CMD_DUMMY; /* sdcmddummy */ > + srcdst = readl(host->base + SPMMC_CARD_MEDIATYPE_SRCDST_REG); > + srcdst |= FIELD_PREP(SPMMC_DMA_SOURCE, 0x2); > + srcdst |= FIELD_PREP(SPMMC_DMA_DESTINATION, 0x1); > + writel(srcdst, host->base + SPMMC_CARD_MEDIATYPE_SRCDST_REG); > + } else { > + value |= FIELD_PREP(SPMMC_SD_TRANS_MODE, 1); > + srcdst = readl(host->base + SPMMC_CARD_MEDIATYPE_SRCDST_REG); > + srcdst |= FIELD_PREP(SPMMC_DMA_SOURCE, 0x1); > + srcdst |= FIELD_PREP(SPMMC_DMA_DESTINATION, 0x2); > + writel(srcdst, host->base + SPMMC_CARD_MEDIATYPE_SRCDST_REG); > + } > + > + value |= SPMMC_SD_LEN_MODE; > + if (likely(host->dmapio_mode == SPMMC_DMA_MODE)) { > + struct scatterlist *sg; > + dma_addr_t dma_addr; > + unsigned int dma_size; > + u32 *reg_addr; > + int dma_direction = data->flags & MMC_DATA_READ ? DMA_FROM_DEVICE : DMA_TO_DEVICE; Feel free to use mmc_get_dma_dir() instead. > + int i, count = 1; > + > + count = dma_map_sg(host->mmc->parent, data->sg, data->sg_len, dma_direction); > + if (unlikely(!count || count > SPMMC_MAX_DMA_MEMORY_SECTORS)) { > + data->error = -EINVAL; > + > + return; > + } > + for_each_sg(data->sg, sg, count, i) { > + dma_addr = sg_dma_address(sg); > + dma_size = sg_dma_len(sg) / data->blksz - 1; > + if (i == 0) { > + writel(dma_addr, host->base + SPMMC_DMA_BASE_ADDR_REG); > + writel(dma_size, host->base + SPMMC_SDRAM_SECTOR_0_SIZE_REG); > + } else { > + reg_addr = host->base + SPMMC_SDRAM_SECTOR_1_ADDR_REG + (i - 1) * 2; > + writel(dma_addr, reg_addr); > + writel(dma_size, reg_addr + 1); > + } > + } > + value &= ~SPMMC_SD_PIO_MODE; /* sdpiomode */ > + writel(value, host->base + SPMMC_SD_CONFIG0_REG); > + /* enable interrupt if needed */ > + if (!host->use_int && data->blksz * data->blocks > host->dma_int_threshold) { > + host->dma_use_int = 1; > + value = readl(host->base + SPMMC_SD_INT_REG); > + value |= SPMMC_SDINT_SDCMPEN; /* sdcmpen */ > + writel(value, host->base + SPMMC_SD_INT_REG); > + } > + } else { > + value |= SPMMC_SD_PIO_MODE; > + value |= SPMMC_RX4_EN; /* rx4_en */ > + writel(value, host->base + SPMMC_SD_CONFIG0_REG); > + } > +} > + > +static inline void spmmc_trigger_transaction(struct spmmc_host *host) > +{ > + u32 value = readl(host->base + SPMMC_SD_CTRL_REG); > + > + value |= SPMMC_NEW_COMMAND_TRIGGER; /* trigger transaction */ > + writel(value, host->base + SPMMC_SD_CTRL_REG); > +} > + > +static void spmmc_send_stop_cmd(struct spmmc_host *host) > +{ > + struct mmc_command stop = {}; > + u32 value; > + > + stop.opcode = MMC_STOP_TRANSMISSION; > + stop.arg = 0; > + stop.flags = MMC_RSP_R1B; > + spmmc_prepare_cmd(host, &stop); > + value = readl(host->base + SPMMC_SD_INT_REG); > + value &= ~SPMMC_SDINT_SDCMPEN; > + value |= FIELD_PREP(SPMMC_SDINT_SDCMPEN, 0); /* sdcmpen */ > + writel(value, host->base + SPMMC_SD_INT_REG); > + spmmc_trigger_transaction(host); > + spmmc_wait_finish(host); > +} > + > +/* > + * check if error occurred during transaction. > + * @host - host > + * @mrq - the mrq > + * @return 0 if no error otherwise the error number. It looks a bit weird that we suddenly start documenting functions like this. Perhaps a simple comment is sufficient? > + */ > +static int spmmc_check_error(struct spmmc_host *host, struct mmc_request *mrq) > +{ > + int ret = 0; > + struct mmc_command *cmd = mrq->cmd; > + struct mmc_data *data = mrq->data; > + > + u32 value = readl(host->base + SPMMC_SD_STATE_REG); > + u32 crc_token = FIELD_GET(SPMMC_CRCTOKEN_CHECK_RESULT, value); > + > + if (unlikely(value & SPMMC_SDSTATE_ERROR)) { > + u32 timing_cfg0 = 0; > + > + value = readl(host->base + SPMMC_SD_STATUS_REG); > + > + if (host->tuning_info.enable_tuning) { > + timing_cfg0 = readl(host->base + SPMMC_SD_TIMING_CONFIG0_REG); > + host->tuning_info.rd_crc_dly = FIELD_GET(SPMMC_SD_READ_CRC_DELAY, > + timing_cfg0); > + host->tuning_info.rd_dat_dly = FIELD_GET(SPMMC_SD_READ_DATA_DELAY, > + timing_cfg0); > + host->tuning_info.rd_rsp_dly = FIELD_GET(SPMMC_SD_READ_RESPONSE_DELAY, > + timing_cfg0); > + host->tuning_info.wr_cmd_dly = FIELD_GET(SPMMC_SD_WRITE_COMMAND_DELAY, > + timing_cfg0); > + host->tuning_info.wr_dat_dly = FIELD_GET(SPMMC_SD_WRITE_DATA_DELAY, > + timing_cfg0); > + } > + > + if (value & SPMMC_SDSTATUS_RSP_TIMEOUT) { > + ret = -ETIMEDOUT; > + host->tuning_info.wr_cmd_dly++; > + } else if (value & SPMMC_SDSTATUS_RSP_CRC7_ERROR) { > + ret = -EILSEQ; > + host->tuning_info.rd_rsp_dly++; > + } else if (data) { > + if ((value & SPMMC_SDSTATUS_STB_TIMEOUT)) { > + ret = -ETIMEDOUT; > + host->tuning_info.rd_dat_dly++; > + } else if (value & SPMMC_SDSTATUS_RDATA_CRC16_ERROR) { > + ret = -EILSEQ; > + host->tuning_info.rd_dat_dly++; > + } else if (value & SPMMC_SDSTATUS_CARD_CRC_CHECK_TIMEOUT) { > + ret = -ETIMEDOUT; > + host->tuning_info.rd_crc_dly++; > + } else if (value & SPMMC_SDSTATUS_CRC_TOKEN_CHECK_ERROR) { > + ret = -EILSEQ; > + if (crc_token == 0x5) > + host->tuning_info.wr_dat_dly++; > + else > + host->tuning_info.rd_crc_dly++; > + } > + } > + cmd->error = ret; > + if (data) { > + data->error = ret; > + data->bytes_xfered = 0; > + } > + if (!host->tuning_info.need_tuning && host->tuning_info.enable_tuning) > + cmd->retries = SPMMC_MAX_RETRIES; /* retry it */ > + spmmc_sw_reset(host); > + usleep_range(5000, 5250); Why these values? Can you please add a comment about why? > + > + if (host->tuning_info.enable_tuning) { > + timing_cfg0 |= FIELD_PREP(SPMMC_SD_READ_CRC_DELAY, > + host->tuning_info.rd_crc_dly); > + timing_cfg0 |= FIELD_PREP(SPMMC_SD_READ_DATA_DELAY, > + host->tuning_info.rd_dat_dly); > + timing_cfg0 |= FIELD_PREP(SPMMC_SD_READ_RESPONSE_DELAY, > + host->tuning_info.rd_rsp_dly); > + timing_cfg0 |= FIELD_PREP(SPMMC_SD_WRITE_COMMAND_DELAY, > + host->tuning_info.wr_cmd_dly); > + timing_cfg0 |= FIELD_PREP(SPMMC_SD_WRITE_DATA_DELAY, > + host->tuning_info.wr_dat_dly); > + writel(timing_cfg0, host->base + SPMMC_SD_TIMING_CONFIG0_REG); > + } > + } else if (data) { > + data->error = 0; > + data->bytes_xfered = data->blocks * data->blksz; > + } > + host->tuning_info.need_tuning = ret; > + /* controller will not send cmd 12 automatically if error occurred */ > + if (cmd->opcode == MMC_READ_MULTIPLE_BLOCK || > + cmd->opcode == MMC_WRITE_MULTIPLE_BLOCK) { > + spmmc_send_stop_cmd(host); > + spmmc_sw_reset(host); > + } > + > + return ret; > +} > + > +/* > + * the strategy is: > + * 1. if several continuous delays are acceptable, we choose a middle one; > + * 2. otherwise, we choose the first one. > + */ > +static inline int __find_best_delay(u8 candidate_dly) > +{ > + int f, w, value; > + > + if (!candidate_dly) > + return 0; > + f = ffs(candidate_dly) - 1; > + w = hweight8(candidate_dly); > + value = ((1 << w) - 1) << f; > + if (0xff == (value & ~candidate_dly)) > + return (f + w / 2); > + else > + return (f); > +} > + > +static inline __maybe_unused void spmmc_txdummy(struct spmmc_host *host, int count) It's certainly unused. Please drop it. > +{ > + u32 value; > + > + count &= 0x1ff; > + value = readl(host->base + SPMMC_SD_CONFIG1_REG); > + value |= FIELD_PREP(SPMMC_TX_DUMMY_NUM, count); > + writel(value, host->base + SPMMC_SD_CONFIG1_REG); > + value = readl(host->base + SPMMC_SD_CTRL_REG); > + value |= SPMMC_DUMMY_CLOCK_TRIGGER; /* trigger tx dummy */ > + writel(value, host->base + SPMMC_SD_CTRL_REG); > +} > + > +static void spmmc_xfer_data_pio(struct spmmc_host *host, struct mmc_data *data) > +{ > + u32 *buf; /* tx/rx 4 bytes one time in pio mode */ Please move the comments to separate lines. > + int data_left = data->blocks * data->blksz; > + int consumed, remain; > + > + struct sg_mapping_iter *sg_miter = &host->sg_miter; > + unsigned int flags = 0; > + > + if (data->flags & MMC_DATA_WRITE) > + flags |= SG_MITER_FROM_SG; > + else > + flags |= SG_MITER_TO_SG; > + sg_miter_start(&host->sg_miter, data->sg, data->sg_len, flags); > + while (data_left > 0) { > + consumed = 0; > + if (!sg_miter_next(sg_miter)) > + break; > + buf = sg_miter->addr; > + remain = sg_miter->length; > + do { > + if (data->flags & MMC_DATA_WRITE) { > + if (spmmc_wait_txbuf_empty(host)) > + goto done; > + writel(*buf, host->base + SPMMC_SD_PIODATATX_REG); > + } else { > + if (spmmc_wait_rxbuf_full(host)) > + goto done; > + *buf = readl(host->base + SPMMC_SD_PIODATARX_REG); > + } > + buf++; > + consumed += 4; > + remain -= 4; > + } while (remain); > + sg_miter->consumed = consumed; > + data_left -= consumed; > + } > +done: > + sg_miter_stop(sg_miter); > +} > + > +static void spmmc_controller_init(struct spmmc_host *host) > +{ > + u32 value; > + int ret = reset_control_assert(host->rstc); > + > + if (!ret) { > + usleep_range(1000, 1250); > + ret = reset_control_deassert(host->rstc); > + } > + > + value = readl(host->base + SPMMC_CARD_MEDIATYPE_SRCDST_REG); > + value |= FIELD_PREP(SPMMC_MEDIA_TYPE, SPMMC_MEDIA_SD); > + writel(value, host->base + SPMMC_CARD_MEDIATYPE_SRCDST_REG); > + host->signal_voltage = MMC_SIGNAL_VOLTAGE_330; I don't see where host->signal_voltage is being used. Please drop it. > +} > + > +static void spmmc_set_power_mode(struct spmmc_host *host, struct mmc_ios *ios) > +{ > + if (host->power_state == ios->power_mode) > + return; > + > + switch (ios->power_mode) { > + /* power off->up->on */ Actually we have MMC_POWER_UNDEFINED too, which is what we start with from the mmc core point of view. > + case MMC_POWER_ON: > + spmmc_controller_init(host); > + pm_runtime_get_sync(host->mmc->parent); Why are you controlling the runtime PM from here? Is the controller itself powering the SD/eMMC card? In most cases we have external regulators for that, see" vmmc" and mmc_regulator_get_supply(). > + break; > + case MMC_POWER_UP: > + break; > + case MMC_POWER_OFF: > + pm_runtime_put(host->mmc->parent); > + break; > + } > + host->power_state = ios->power_mode; > +} > + > +/* > + * 1. unmap scatterlist if needed; > + * 2. get response & check error conditions; > + * 3. unlock host->mrq_lock > + * 4. notify mmc layer the request is done > + */ > +static void spmmc_finish_request(struct spmmc_host *host, struct mmc_request *mrq) > +{ > + struct mmc_command *cmd; > + struct mmc_data *data; > + > + if (!mrq) > + return; > + > + cmd = mrq->cmd; > + data = mrq->data; > + > + if (data && SPMMC_DMA_MODE == host->dmapio_mode) { > + int dma_direction = data->flags & MMC_DATA_READ ? DMA_FROM_DEVICE : DMA_TO_DEVICE; mmc_get_dma_dir() > + > + dma_unmap_sg(host->mmc->parent, data->sg, data->sg_len, dma_direction); > + host->dma_use_int = 0; > + } > + spmmc_get_rsp(host, cmd); > + spmmc_check_error(host, mrq); > + host->mrq = NULL; > + mmc_request_done(host->mmc, mrq); > +} > + > +/* Interrupt Service Routine */ > +static irqreturn_t spmmc_irq(int irq, void *dev_id) > +{ > + struct spmmc_host *host = dev_id; > + u32 value = readl(host->base + SPMMC_SD_INT_REG); > + > + spin_lock(&host->lock); > + if ((value & SPMMC_SDINT_SDCMP) && (value & SPMMC_SDINT_SDCMPEN)) { > + value &= ~SPMMC_SDINT_SDCMPEN; /* disable sdcmp */ > + value |= SPMMC_SDINT_SDCMPCLR; /* sd_cmp_clr */ > + writel(value, host->base + SPMMC_SD_INT_REG); > + /* > + * if error occurred, we my need send cmd 12 to stop data transaction, > + * which is time consuming, so make use of tasklet to handle this. > + */ > + if (unlikely(readl(host->base + SPMMC_SD_STATE_REG) & SPMMC_SDSTATE_ERROR)) > + tasklet_schedule(&host->tsklet_finish_req); As I stated earlier, please use a threaded IRQ instead. > + else > + spmmc_finish_request(host, host->mrq); > + } > + if (value & SPMMC_SDINT_SDIO && > + (value & SPMMC_SDINT_SDIOEN)) { > + mmc_signal_sdio_irq(host->mmc); I was under the impression that SDIO support was going to be added on top. I suggest we drop this for now. Moreover, mmc_signal_sdio_irq() is the legacy interface. Please use sdio_signal_irq() instead, which also comes along with a few new host callbacks that need to be implemented. > + } > + spin_unlock(&host->lock); > + > + return IRQ_HANDLED; > +} > + > + [...] > +/* > + * Return values for the get_cd callback should be: > + * 0 for a absent card > + * 1 for a present card > + * -ENOSYS when not supported (equal to NULL callback) > + * or a negative errno value when something bad happened > + */ > +static int spmmc_get_cd(struct mmc_host *mmc) > +{ > + int ret = 0; > + > + if (mmc_can_gpio_cd(mmc)) > + ret = mmc_gpio_get_cd(mmc); > + > + if (ret < 0) > + ret = 0; > + > + return ret; > +} > + > +static int spmmc_execute_tuning(struct mmc_host *mmc, u32 opcode) > +{ > + struct spmmc_host *host = mmc_priv(mmc); > + const u8 *blk_pattern; > + u8 *blk_test; > + int blksz; > + u8 smpl_dly = 0, candidate_dly = 0; > + u32 value; > + > + if (mmc->ios.bus_width == MMC_BUS_WIDTH_8) { > + blk_pattern = tuning_blk_pattern_8bit; > + blksz = sizeof(tuning_blk_pattern_8bit); > + } else if (mmc->ios.bus_width == MMC_BUS_WIDTH_4) { > + blk_pattern = tuning_blk_pattern_4bit; > + blksz = sizeof(tuning_blk_pattern_4bit); > + } else { > + return -EINVAL; > + } > + > + blk_test = kmalloc(blksz, GFP_KERNEL); > + if (!blk_test) > + return -ENOMEM; > + > + host->tuning_info.enable_tuning = 0; > + do { > + struct mmc_request mrq = {NULL}; > + struct mmc_command cmd = {0}; > + struct mmc_command stop = {0}; > + struct mmc_data data = {0}; > + struct scatterlist sg; > + > + cmd.opcode = opcode; > + cmd.arg = 0; > + cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC; > + > + stop.opcode = MMC_STOP_TRANSMISSION; > + stop.arg = 0; > + stop.flags = MMC_RSP_R1B | MMC_CMD_AC; > + > + data.blksz = blksz; > + data.blocks = 1; > + data.flags = MMC_DATA_READ; > + data.sg = &sg; > + data.sg_len = 1; > + > + sg_init_one(&sg, blk_test, blksz); > + mrq.cmd = &cmd; > + mrq.stop = &stop; > + mrq.data = &data; > + host->mrq = &mrq; Please convert this code into using mmc_send_tuning() and mmc_send_abort_tuning() instead. > + > + value = readl(host->base + SPMMC_SD_TIMING_CONFIG0_REG); > + value |= FIELD_PREP(SPMMC_SD_READ_RESPONSE_DELAY, smpl_dly); > + value |= FIELD_PREP(SPMMC_SD_READ_DATA_DELAY, smpl_dly); > + value |= FIELD_PREP(SPMMC_SD_READ_CRC_DELAY, smpl_dly); > + writel(value, host->base + SPMMC_SD_TIMING_CONFIG0_REG); > + > + mmc_wait_for_req(mmc, &mrq); > + if (!cmd.error && !data.error) { > + if (!memcmp(blk_pattern, blk_test, blksz)) > + candidate_dly |= (1 << smpl_dly); > + } > + } while (smpl_dly++ <= SPMMC_MAX_TUNABLE_DLY); > + host->tuning_info.enable_tuning = 1; > + > + if (candidate_dly) { > + smpl_dly = __find_best_delay(candidate_dly); > + value = readl(host->base + SPMMC_SD_TIMING_CONFIG0_REG); > + value |= FIELD_PREP(SPMMC_SD_READ_RESPONSE_DELAY, smpl_dly); > + value |= FIELD_PREP(SPMMC_SD_READ_DATA_DELAY, smpl_dly); > + value |= FIELD_PREP(SPMMC_SD_READ_CRC_DELAY, smpl_dly); > + writel(value, host->base + SPMMC_SD_TIMING_CONFIG0_REG); > + return 0; > + } > + > + return -EIO; > +} > + > +static void spmmc_enable_sdio_irq(struct mmc_host *mmc, int enable) Let's drop SDIO support for now. > +{ > + struct spmmc_host *host = mmc_priv(mmc); > + u32 value = readl(host->base + SPMMC_SD_INT_REG); > + > + value &= ~SPMMC_SDINT_SDIOCLR; > + value |= FIELD_PREP(SPMMC_SDINT_SDIOCLR, 1); /* sdio_int_clr */ > + if (enable) > + value |= SPMMC_SDINT_SDIOEN; > + else > + value &= ~SPMMC_SDINT_SDIOEN; > + writel(value, host->base + SPMMC_SD_INT_REG); > +} > + [...] > + > +static int spmmc_drv_probe(struct platform_device *pdev) > +{ > + struct mmc_host *mmc; > + struct resource *res; > + struct spmmc_host *host; > + int ret = 0; > + > + mmc = mmc_alloc_host(sizeof(*host), &pdev->dev); > + if (!mmc) { > + ret = -ENOMEM; > + goto probe_free_host; > + } > + > + host = mmc_priv(mmc); > + host->mmc = mmc; > + host->power_state = MMC_POWER_OFF; > + host->dma_int_threshold = 1024; > + host->dmapio_mode = SPMMC_DMA_MODE; > + > + host->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res); > + if (IS_ERR(host->base)) > + return PTR_ERR(host->base); > + > + host->clk = devm_clk_get(&pdev->dev, NULL); > + if (IS_ERR(host->clk)) > + return dev_err_probe(&pdev->dev, PTR_ERR(host->clk), "clk get fail\n"); > + > + host->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL); > + if (IS_ERR(host->rstc)) > + return dev_err_probe(&pdev->dev, PTR_ERR(host->rstc), "rst get fail\n"); > + > + host->irq = platform_get_irq(pdev, 0); > + if (host->irq <= 0) > + return host->irq; > + > + ret = devm_request_irq(&pdev->dev, host->irq, spmmc_irq, IRQF_SHARED, > + dev_name(&pdev->dev), host); > + if (ret) > + return ret; > + > + ret = clk_prepare_enable(host->clk); > + if (ret) > + return dev_err_probe(&pdev->dev, ret, "failed to enable clk\n"); > + > + ret = mmc_of_parse(mmc); > + if (ret) > + goto probe_free_host; > + > + spin_lock_init(&host->lock); > + mutex_init(&host->mrq_lock); > + tasklet_init(&host->tsklet_finish_req, tsklet_func_finish_req, (unsigned long)host); > + mmc->ops = &spmmc_ops; > + mmc->f_min = SPMMC_MIN_CLK; > + if (mmc->f_max > SPMMC_MAX_CLK) > + mmc->f_max = SPMMC_MAX_CLK; > + > + mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34; Please use mmc_regulator_get_supply() to get the ocr_avail mask instead of hardcoding it. > + mmc->max_seg_size = SPMMC_MAX_BLK_COUNT * 512; > + /* Host controller supports up to "SPMMC_MAX_DMA_MEMORY_SECTORS"*/ > + /* a.k.a. max scattered memory segments per request*/ > + mmc->max_segs = SPMMC_MAX_DMA_MEMORY_SECTORS; > + mmc->max_req_size = SPMMC_MAX_BLK_COUNT * 512; > + /* Limited by the max value of dma_size & data_length, set it to 512 bytes for now */ > + mmc->max_blk_size = 512; > + mmc->max_blk_count = SPMMC_MAX_BLK_COUNT; /* Limited by sd_page_num */ Please re-format the code and comment above so it becomes it more readable. Perhaps a few newlines would help. > + > + dev_set_drvdata(&pdev->dev, host); > + spmmc_controller_init(host); > + spmmc_select_mode(host); > + mmc_add_host(mmc); > + host->tuning_info.enable_tuning = 1; > + pm_runtime_set_active(&pdev->dev); > + pm_runtime_enable(&pdev->dev); To be safe, I suggest you call mmc_add_host() as the last thing in ->probe(). Otherwise you end up enabling runtime PM, when the host is already up and running from the core point of view. > + > + return ret; > + > +probe_free_host: > + if (mmc) > + mmc_free_host(mmc); > + > + return ret; > +} > + > +static int spmmc_drv_remove(struct platform_device *dev) > +{ > + struct spmmc_host *host = platform_get_drvdata(dev); > + > + mmc_remove_host(host->mmc); > + clk_disable(host->clk); > + clk_unprepare(host->clk); clk_disable_unprepare(). > + pm_runtime_disable(&dev->dev); > + platform_set_drvdata(dev, NULL); > + mmc_free_host(host->mmc); > + > + return 0; > +} > + > +static int spmmc_drv_suspend(struct platform_device *dev, pm_message_t state) This is a legacy PM callback, please drop it. > +{ > + struct spmmc_host *host; > + > + host = platform_get_drvdata(dev); > + mutex_lock(&host->mrq_lock); /* Make sure that no one is holding the controller */ > + mutex_unlock(&host->mrq_lock); > + clk_disable(host->clk); > + > + return 0; > +} > + > +static int spmmc_drv_resume(struct platform_device *dev) Ditto. > +{ > + struct spmmc_host *host; > + > + host = platform_get_drvdata(dev); > + > + return clk_enable(host->clk); > +} > + > +static int spmmc_pm_suspend(struct device *dev) > +{ > + pm_runtime_force_suspend(dev); Just point the PM callback to pm_runtime_force_suspend() instead of adding an unessary wrapper function. > + > + return 0; > +} > + > +static int spmmc_pm_resume(struct device *dev) > +{ > + pm_runtime_force_resume(dev); Just point the PM callback to pm_runtime_force_resume() instead of adding an unessary wrapper function. > + > + return 0; > +} > + > +static int spmmc_pm_runtime_suspend(struct device *dev) You proably need __maybe_unused here. > +{ > + struct spmmc_host *host; > + > + host = dev_get_drvdata(dev); > + clk_disable(host->clk); clk_disable_unprepare() > + > + return 0; > +} > + > +static int spmmc_pm_runtime_resume(struct device *dev) You proably need __maybe_unused here. > +{ > + struct spmmc_host *host; > + > + host = dev_get_drvdata(dev); > + > + return clk_enable(host->clk); clk_prepare_enable(). > +} > + > +static const struct dev_pm_ops spmmc_pm_ops = { > + SYSTEM_SLEEP_PM_OPS(spmmc_pm_suspend, spmmc_pm_resume) > + RUNTIME_PM_OPS(spmmc_pm_runtime_suspend, spmmc_pm_runtime_resume, NULL) > +}; > + > +static const struct of_device_id spmmc_of_table[] = { > + { > + .compatible = "sunplus,sp7021-mmc", > + }, > + {/* sentinel */} > +}; > +MODULE_DEVICE_TABLE(of, spmmc_of_table); > + > +static struct platform_driver spmmc_driver = { > + .probe = spmmc_drv_probe, > + .remove = spmmc_drv_remove, > + .suspend = spmmc_drv_suspend, > + .resume = spmmc_drv_resume, > + .driver = { > + .name = "spmmc", > + .pm = pm_ptr(&spmmc_pm_ops), > + .of_match_table = spmmc_of_table, > + }, > +}; > +module_platform_driver(spmmc_driver); > + > +MODULE_AUTHOR("Tony Huang <tonyhuang.sunplus@xxxxxxxxx>"); > +MODULE_AUTHOR("Li-hao Kuo <lhjeff911@xxxxxxxxx>"); > +MODULE_DESCRIPTION("Sunplus MMC controller driver"); > +MODULE_LICENSE("GPL"); > -- > 2.7.4 > Kind regards Uffe