The TMOUT register is always set with a full value for every transfer,
which (with a 200MHz clock) will give a full DRTO of ~84 milliseconds.
This is normally good enough to complete the request, but setting a full
value makes it impossible to test shorter timeouts, when for example
testing data read times on different SD cards.
Add a function to set any value smaller than the maximum of 0xFFFFFF.
Signed-off-by: Mårten Lindahl <marten.lindahl@xxxxxxxx>
---
v2:
- Calculate new value before checking boundaries
- Include CLKDIV register to get proper value
v3:
- Use 'if-else' instead of 'goto'
- Don't touch response field when maximize data field
v4:
- Prevent 32bit divider overflow by splitting the operation
- Changed %06x to %#08x as suggested by Doug
- Rephrased commit msg as suggested by Doug
drivers/mmc/host/dw_mmc.c | 28 +++++++++++++++++++++++++++-
1 file changed, 27 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index d977f34f6b55..8e9d33e1b96c 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -1283,6 +1283,32 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot, bool force_clkinit)
mci_writel(host, CTYPE, (slot->ctype << slot->id));
}
+static void dw_mci_set_data_timeout(struct dw_mci *host,
+ unsigned int timeout_ns)
+{
+ unsigned int clk_div, tmp, tmout;
+
+ clk_div = (mci_readl(host, CLKDIV) & 0xFF) * 2;
+ if (clk_div == 0)
+ clk_div = 1;
+
+ tmp = DIV_ROUND_UP_ULL((u64)timeout_ns * host->bus_hz, NSEC_PER_SEC);
+ tmp = DIV_ROUND_UP(tmp, clk_div);
+
+ /* TMOUT[7:0] (RESPONSE_TIMEOUT) */
+ tmout = 0xFF; /* Set maximum */
+
+ /* TMOUT[31:8] (DATA_TIMEOUT) */
+ if (!tmp || tmp > 0xFFFFFF)
+ tmout |= (0xFFFFFF << 8);
+ else
+ tmout |= (tmp & 0xFFFFFF) << 8;
+
+ mci_writel(host, TMOUT, tmout);
+ dev_dbg(host->dev, "timeout_ns: %u => TMOUT[31:8]: 0x%#08x",
+ timeout_ns, tmout >> 8);
+}
+
static void __dw_mci_start_request(struct dw_mci *host,
struct dw_mci_slot *slot,
struct mmc_command *cmd)
@@ -1303,7 +1329,7 @@ static void __dw_mci_start_request(struct dw_mci *host,
data = cmd->data;
if (data) {
- mci_writel(host, TMOUT, 0xFFFFFFFF);
+ dw_mci_set_data_timeout(host, data->timeout_ns);
mci_writel(host, BYTCNT, data->blksz*data->blocks);
mci_writel(host, BLKSIZ, data->blksz);
}
--
2.20.1
