From 06f438dd389a699d27585f2a4d3685fd1ce05a75 Mon Sep 17 00:00:00 2001 From: Simon Horman Date: Thu, 3 Nov 2016 15:16:04 +0100 Subject: [PATCH] mmc: sh_mobile_sdhi: Add tuning support Add tuning support for use with SDR104 mode This includes adding support for the sampling clock controller (SCC). Based on work by Ai Kyuse. Cc: Ai Kyuse Signed-off-by: Simon Horman Acked-by: Wolfram Sang Tested-by: Wolfram Sang Signed-off-by: Ulf Hansson --- drivers/mmc/host/sh_mobile_sdhi.c | 265 +++++++++++++++++++++++++++++- 1 file changed, 264 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/host/sh_mobile_sdhi.c b/drivers/mmc/host/sh_mobile_sdhi.c index bda5e6745701..d46c2d00c182 100644 --- a/drivers/mmc/host/sh_mobile_sdhi.c +++ b/drivers/mmc/host/sh_mobile_sdhi.c @@ -47,6 +47,11 @@ #define host_to_priv(host) container_of((host)->pdata, struct sh_mobile_sdhi, mmc_data) +struct sh_mobile_sdhi_scc { + unsigned long clk_rate; /* clock rate for SDR104 */ + u32 tap; /* sampling clock position for SDR104 */ +}; + struct sh_mobile_sdhi_of_data { unsigned long tmio_flags; u32 tmio_ocr_mask; @@ -55,6 +60,9 @@ struct sh_mobile_sdhi_of_data { enum dma_slave_buswidth dma_buswidth; dma_addr_t dma_rx_offset; unsigned bus_shift; + int scc_offset; + struct sh_mobile_sdhi_scc *taps; + int taps_num; }; static const struct sh_mobile_sdhi_of_data of_default_cfg = { @@ -73,12 +81,35 @@ static const struct sh_mobile_sdhi_of_data of_rcar_gen1_compatible = { .capabilities = MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ, }; +/* Definitions for sampling clocks */ +static struct sh_mobile_sdhi_scc rcar_gen2_scc_taps[] = { + { + .clk_rate = 156000000, + .tap = 0x00000703, + }, + { + .clk_rate = 0, + .tap = 0x00000300, + }, +}; + static const struct sh_mobile_sdhi_of_data of_rcar_gen2_compatible = { .tmio_flags = TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_WRPROTECT_DISABLE | TMIO_MMC_CLK_ACTUAL | TMIO_MMC_MIN_RCAR2, .capabilities = MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ, .dma_buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES, .dma_rx_offset = 0x2000, + .scc_offset = 0x0300, + .taps = rcar_gen2_scc_taps, + .taps_num = ARRAY_SIZE(rcar_gen2_scc_taps), +}; + +/* Definitions for sampling clocks */ +static struct sh_mobile_sdhi_scc rcar_gen3_scc_taps[] = { + { + .clk_rate = 0, + .tap = 0x00000300, + }, }; static const struct sh_mobile_sdhi_of_data of_rcar_gen3_compatible = { @@ -86,6 +117,9 @@ static const struct sh_mobile_sdhi_of_data of_rcar_gen3_compatible = { TMIO_MMC_CLK_ACTUAL | TMIO_MMC_MIN_RCAR2, .capabilities = MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ, .bus_shift = 2, + .scc_offset = 0x1000, + .taps = rcar_gen3_scc_taps, + .taps_num = ARRAY_SIZE(rcar_gen3_scc_taps), }; static const struct of_device_id sh_mobile_sdhi_of_match[] = { @@ -113,6 +147,7 @@ struct sh_mobile_sdhi { struct tmio_mmc_dma dma_priv; struct pinctrl *pinctrl; struct pinctrl_state *pins_default, *pins_uhs; + void __iomem *scc_ctl; }; static void sh_mobile_sdhi_sdbuf_width(struct tmio_mmc_host *host, int width) @@ -263,6 +298,201 @@ static int sh_mobile_sdhi_start_signal_voltage_switch(struct mmc_host *mmc, return pinctrl_select_state(priv->pinctrl, pin_state); } +/* SCC registers */ +#define SH_MOBILE_SDHI_SCC_DTCNTL 0x000 +#define SH_MOBILE_SDHI_SCC_TAPSET 0x002 +#define SH_MOBILE_SDHI_SCC_DT2FF 0x004 +#define SH_MOBILE_SDHI_SCC_CKSEL 0x006 +#define SH_MOBILE_SDHI_SCC_RVSCNTL 0x008 +#define SH_MOBILE_SDHI_SCC_RVSREQ 0x00A + +/* Definitions for values the SH_MOBILE_SDHI_SCC_DTCNTL register */ +#define SH_MOBILE_SDHI_SCC_DTCNTL_TAPEN BIT(0) +#define SH_MOBILE_SDHI_SCC_DTCNTL_TAPNUM_SHIFT 16 +#define SH_MOBILE_SDHI_SCC_DTCNTL_TAPNUM_MASK 0xff + +/* Definitions for values the SH_MOBILE_SDHI_SCC_CKSEL register */ +#define SH_MOBILE_SDHI_SCC_CKSEL_DTSEL BIT(0) +/* Definitions for values the SH_MOBILE_SDHI_SCC_RVSCNTL register */ +#define SH_MOBILE_SDHI_SCC_RVSCNTL_RVSEN BIT(0) +/* Definitions for values the SH_MOBILE_SDHI_SCC_RVSREQ register */ +#define SH_MOBILE_SDHI_SCC_RVSREQ_RVSERR BIT(2) + +static inline u32 sd_scc_read32(struct tmio_mmc_host *host, + struct sh_mobile_sdhi *priv, int addr) +{ + return readl(priv->scc_ctl + (addr << host->bus_shift)); +} + +static inline void sd_scc_write32(struct tmio_mmc_host *host, + struct sh_mobile_sdhi *priv, + int addr, u32 val) +{ + writel(val, priv->scc_ctl + (addr << host->bus_shift)); +} + +static unsigned int sh_mobile_sdhi_init_tuning(struct tmio_mmc_host *host) +{ + struct sh_mobile_sdhi *priv; + + if (!(host->mmc->caps & MMC_CAP_UHS_SDR104)) + return 0; + + priv = host_to_priv(host); + + /* set sampling clock selection range */ + sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_DTCNTL, + 0x8 << SH_MOBILE_SDHI_SCC_DTCNTL_TAPNUM_SHIFT); + + /* Initialize SCC */ + sd_ctrl_write32_as_16_and_16(host, CTL_STATUS, 0x0); + + sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_DTCNTL, + SH_MOBILE_SDHI_SCC_DTCNTL_TAPEN | + sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_DTCNTL)); + + sd_ctrl_write16(host, CTL_SD_CARD_CLK_CTL, ~CLK_CTL_SCLKEN & + sd_ctrl_read16(host, CTL_SD_CARD_CLK_CTL)); + + sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_CKSEL, + SH_MOBILE_SDHI_SCC_CKSEL_DTSEL | + sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_CKSEL)); + + sd_ctrl_write16(host, CTL_SD_CARD_CLK_CTL, CLK_CTL_SCLKEN | + sd_ctrl_read16(host, CTL_SD_CARD_CLK_CTL)); + + sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_RVSCNTL, + ~SH_MOBILE_SDHI_SCC_RVSCNTL_RVSEN & + sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_RVSCNTL)); + + sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_DT2FF, host->scc_tappos); + + /* Read TAPNUM */ + return (sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_DTCNTL) >> + SH_MOBILE_SDHI_SCC_DTCNTL_TAPNUM_SHIFT) & + SH_MOBILE_SDHI_SCC_DTCNTL_TAPNUM_MASK; +} + +static void sh_mobile_sdhi_prepare_tuning(struct tmio_mmc_host *host, + unsigned long tap) +{ + struct sh_mobile_sdhi *priv = host_to_priv(host); + + /* Set sampling clock position */ + sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_TAPSET, tap); +} + +#define SH_MOBILE_SDHI_MAX_TAP 3 + +static int sh_mobile_sdhi_select_tuning(struct tmio_mmc_host *host) +{ + struct sh_mobile_sdhi *priv = host_to_priv(host); + unsigned long tap_cnt; /* counter of tuning success */ + unsigned long tap_set; /* tap position */ + unsigned long tap_start;/* start position of tuning success */ + unsigned long tap_end; /* end position of tuning success */ + unsigned long ntap; /* temporary counter of tuning success */ + unsigned long i; + + /* Clear SCC_RVSREQ */ + sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_RVSREQ, 0); + + /* + * Find the longest consecutive run of successful probes. If that + * is more than SH_MOBILE_SDHI_MAX_TAP probes long then use the + * center index as the tap. + */ + tap_cnt = 0; + ntap = 0; + tap_start = 0; + tap_end = 0; + for (i = 0; i < host->tap_num * 2; i++) { + if (test_bit(i, host->taps)) + ntap++; + else { + if (ntap > tap_cnt) { + tap_start = i - ntap; + tap_end = i - 1; + tap_cnt = ntap; + } + ntap = 0; + } + } + + if (ntap > tap_cnt) { + tap_start = i - ntap; + tap_end = i - 1; + tap_cnt = ntap; + } + + if (tap_cnt >= SH_MOBILE_SDHI_MAX_TAP) + tap_set = (tap_start + tap_end) / 2 % host->tap_num; + else + return -EIO; + + /* Set SCC */ + sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_TAPSET, tap_set); + + /* Enable auto re-tuning */ + sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_RVSCNTL, + SH_MOBILE_SDHI_SCC_RVSCNTL_RVSEN | + sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_RVSCNTL)); + + return 0; +} + + +static bool sh_mobile_sdhi_check_scc_error(struct tmio_mmc_host *host) +{ + struct sh_mobile_sdhi *priv; + + if (!(host->mmc->caps & MMC_CAP_UHS_SDR104)) + return 0; + + priv = host_to_priv(host); + + /* Check SCC error */ + if (sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_RVSCNTL) & + SH_MOBILE_SDHI_SCC_RVSCNTL_RVSEN && + sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_RVSREQ) & + SH_MOBILE_SDHI_SCC_RVSREQ_RVSERR) { + /* Clear SCC error */ + sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_RVSREQ, 0); + return true; + } + + return false; +} + +static void sh_mobile_sdhi_hw_reset(struct tmio_mmc_host *host) +{ + struct sh_mobile_sdhi *priv; + + if (!(host->mmc->caps & MMC_CAP_UHS_SDR104)) + return; + + priv = host_to_priv(host); + + /* Reset SCC */ + sd_ctrl_write16(host, CTL_SD_CARD_CLK_CTL, ~CLK_CTL_SCLKEN & + sd_ctrl_read16(host, CTL_SD_CARD_CLK_CTL)); + + sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_CKSEL, + ~SH_MOBILE_SDHI_SCC_CKSEL_DTSEL & + sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_CKSEL)); + + sd_ctrl_write16(host, CTL_SD_CARD_CLK_CTL, CLK_CTL_SCLKEN | + sd_ctrl_read16(host, CTL_SD_CARD_CLK_CTL)); + + sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_RVSCNTL, + ~SH_MOBILE_SDHI_SCC_RVSCNTL_RVSEN & + sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_RVSCNTL)); + + sd_scc_write32(host, priv, SH_MOBILE_SDHI_SCC_RVSCNTL, + ~SH_MOBILE_SDHI_SCC_RVSCNTL_RVSEN & + sd_scc_read32(host, priv, SH_MOBILE_SDHI_SCC_RVSCNTL)); +} + static int sh_mobile_sdhi_wait_idle(struct tmio_mmc_host *host) { int timeout = 1000; @@ -333,7 +563,7 @@ static int sh_mobile_sdhi_probe(struct platform_device *pdev) struct tmio_mmc_data *mmd = pdev->dev.platform_data; struct tmio_mmc_host *host; struct resource *res; - int irq, ret, i = 0; + int irq, ret, i; struct tmio_mmc_dma *dma_priv; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); @@ -393,6 +623,11 @@ static int sh_mobile_sdhi_probe(struct platform_device *pdev) host->card_busy = sh_mobile_sdhi_card_busy; host->start_signal_voltage_switch = sh_mobile_sdhi_start_signal_voltage_switch; + host->init_tuning = sh_mobile_sdhi_init_tuning; + host->prepare_tuning = sh_mobile_sdhi_prepare_tuning; + host->select_tuning = sh_mobile_sdhi_select_tuning; + host->check_scc_error = sh_mobile_sdhi_check_scc_error; + host->hw_reset = sh_mobile_sdhi_hw_reset; } /* Orginally registers were 16 bit apart, could be 32 or 64 nowadays */ @@ -433,6 +668,34 @@ static int sh_mobile_sdhi_probe(struct platform_device *pdev) if (ret < 0) goto efree; + if (host->mmc->caps & MMC_CAP_UHS_SDR104) { + host->mmc->caps |= MMC_CAP_HW_RESET; + + if (of_id && of_id->data) { + const struct sh_mobile_sdhi_of_data *of_data; + const struct sh_mobile_sdhi_scc *taps; + bool hit = false; + + of_data = of_id->data; + taps = of_data->taps; + + for (i = 0; i < of_data->taps_num; i++) { + if (taps[i].clk_rate == 0 || + taps[i].clk_rate == host->mmc->f_max) { + host->scc_tappos = taps->tap; + hit = true; + break; + } + } + + if (!hit) + dev_warn(&host->pdev->dev, "Unknown clock rate for SDR104\n"); + + priv->scc_ctl = host->ctl + of_data->scc_offset; + } + } + + i = 0; while (1) { irq = platform_get_irq(pdev, i); if (irq < 0) -- 2.20.1