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 <ai.kyuse.uw@xxxxxxxxxxx>
Signed-off-by: Simon Horman <horms+renesas@xxxxxxxxxxxx>
---
v6 [Simon Horman]
* Rebase to use host->taps
v5 [Simon Horman]
* As suggested by Ulf Hansson
- Use more descriptive name for callback to check for SSC error
* Correct return statement in sh_mobile_sdhi_hw_reset
* Reinstate Gen3 tuning support
v4 [Simon Horman]
As suggested by Geert Uytterhoeven:
* guard SDR104 specific portion of probe with host->mmc->caps &
MMC_CAP_UHS_SDR104
* As suggested by Wolfram Sang:
- Pass priv to sd_scc_{read,write}32 to save host_to_priv access
for each call
- Use 0x0 instead of other representations of 0 in hex
- Use CLK_CTL_SCLKEN
- Do not add unused SH_MOBILE_SDHI_MAX_TAP
- Use ternary operator in sh_mobile_sdhi_select_tuning
- Do include as yet unsupported HS200 in error string
* Reintroduce retuning support: This was removed in v3.
* Revert to algorithm in v1 patchset, on further reading of the documentation
it appears to be correct.
v3 [Simon Horman]
* As suggested by Kuninori Morimoto:
- Do not add unused retuning callback to struct tmio_mmc_host
- Change return type of prepare_tuning callback to void
- Add tap_size parameter to select_tuning callback
v2 [Simon Horman]
* As suggested by Kuninori Morimoto
- Use host->mmc->caps & MMC_CAP_UHS_SDR104 instead of
pdata->flags & TMIO_MMC_HAS_UHS_SCC to avoid needing the
MMC_CAP_UHS_SDR104 flag at all.
N.B: Morimoto-san suggested using but this flag is not actually
set there in by current probe come.
- Simplify logic in sh_mobile_sdhi_inquiry_tuning
* As suggested by Wolfram Sang
- Use clk_rate instead of clk for field in struct sh_mobile_sdhi_scc
- Remove inquiry_tuning callback which is now unnecessary as calling
of tuning is handled by the core
- Removed unused sh_mobile_sdhi_set_clk_div callback
- Save sci_base address rather than calculating it on each read and write
* Update selection logic in sh_mobile_sdhi_select_tuning to match spec
* Use bool instead of long for taps parameter of
sh_mobile_sdhi_select_tuning()
* Return 0 from sh_mobile_sdhi_init_tuning() if the
SDR104 capability is not set and thus tuning should not
be performed because it is not supported by the hardware
v1 [Simon Horman]
* Rebase
* Always use value of 0x8 for TAPNUM field of DTCNTL register
rather than reading value from DT property. There does not
seem to be a need to expose this in DT at this point.
* Do not include tmio_mmc_start_signal_voltage_switch changes which
are already in mainline in a different form
* Do not add renesas,clk-rate property as the max-frequency property, which
is now present in mainline, seems to provide the needed rate
* Omit Gen3 specific changes
* Do not provide renesas,mmc-scc-tappos DT property.
Instead, always use taps provided in driver.
* Do not parse sd-uhs-sdr50 and sd-uhs-sdr104 properties.
This is handled by the core.
v0 [Ai Kyuse]
Signed-off-by: Simon Horman <horms+renesas@xxxxxxxxxxxx>
---
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 49edff7fee49..32d3e01e0840 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;
unsigned long capabilities;
@@ -54,6 +59,9 @@ 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 = {
@@ -66,12 +74,35 @@ 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 = {
@@ -79,6 +110,9 @@ 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[] = {
@@ -105,6 +139,7 @@ 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)
@@ -255,6 +290,201 @@ 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(1)
+/* 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;
@@ -325,7 +555,7 @@ 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);
@@ -384,6 +614,11 @@ 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 */
@@ -424,6 +659,34 @@ 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)
--
2.7.0.rc3.207.g0ac5344
