mmc: dw_mmc: Add driver callbacks for data read timeout

Current dw_mci driver supports a TMOUT register which consists of a 24
bit field (TMOUT[31:8]) for the DATA_TIMEOUT. The maximum value of this
field is 0xFFFFFF, which with a 200MHz clock will give a full DRTO of:

0xFFFFFF / 200000000 => ~84 ms

However, the ARTPEC-8 SoC DWMMC IP version has a TMOUT register with an
extended DATA_TIMEOUT field, which supports longer timers for the DRTO.
In this version the DATA_TIMEOUT field is split into two, which with the
same 200MHz clock as above will allow a maximum timeout of:

((TMOUT[10:8] -1) * 0xFFFFFF + TMOUT[31:11] * 8) / 200000000 => ~587 ms

Add driver callbacks for implementation specific data timeout, and
implement callback functions for the ARTPEC-8 SoC.

Signed-off-by: Mårten Lindahl <marten.lindahl@axis.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20211220113026.21129-4-marten.lindahl@axis.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

1 files changed, 11 insertions, 1 deletions

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index bec4796283fe..05b72b3c5dc0 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -1287,9 +1287,13 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot, bool force_clkinit)
 static void dw_mci_set_data_timeout(struct dw_mci *host,
 				    unsigned int timeout_ns)
 {
+	const struct dw_mci_drv_data *drv_data = host->drv_data;
 	u32 clk_div, tmout;
 	u64 tmp;
 
+	if (drv_data && drv_data->set_data_timeout)
+		return drv_data->set_data_timeout(host, timeout_ns);
+
 	clk_div = (mci_readl(host, CLKDIV) & 0xFF) * 2;
 	if (clk_div == 0)
 		clk_div = 1;
@@ -1995,12 +1999,16 @@ static int dw_mci_data_complete(struct dw_mci *host, struct mmc_data *data)
 
 static void dw_mci_set_drto(struct dw_mci *host)
 {
+	const struct dw_mci_drv_data *drv_data = host->drv_data;
 	unsigned int drto_clks;
 	unsigned int drto_div;
 	unsigned int drto_ms;
 	unsigned long irqflags;
 
-	drto_clks = mci_readl(host, TMOUT) >> 8;
+	if (drv_data && drv_data->get_drto_clks)
+		drto_clks = drv_data->get_drto_clks(host);
+	else
+		drto_clks = mci_readl(host, TMOUT) >> 8;
 	drto_div = (mci_readl(host, CLKDIV) & 0xff) * 2;
 	if (drto_div == 0)
 		drto_div = 1;
@@ -2008,6 +2016,8 @@ static void dw_mci_set_drto(struct dw_mci *host)
 	drto_ms = DIV_ROUND_UP_ULL((u64)MSEC_PER_SEC * drto_clks * drto_div,
 				   host->bus_hz);
 
+	dev_dbg(host->dev, "drto_ms: %u\n", drto_ms);
+
 	/* add a bit spare time */
 	drto_ms += 10;