Thread (41 messages) 41 messages, 3 authors, 2018-07-30

[PATCH 06/19] mmc: mmci: add variant properties to define cpsm & cmdresp bits

From: Ulf Hansson <hidden>
Date: 2018-07-05 14:20:49
Also in: linux-devicetree, linux-mmc, lkml

On 12 June 2018 at 15:14, Ludovic Barre [off-list ref] wrote:
quoted hunk ↗ jump to hunk
From: Ludovic Barre <redacted>

This patch adds command variant properties to define
cpsm enable bit and responses.
Needed to support the STM32 variant (shift of cpsm bit,
specific definition of commands response).

Signed-off-by: Ludovic Barre <redacted>
---
 drivers/mmc/host/mmci.c | 47 +++++++++++++++++++++++++++++++++++++++++++----
 drivers/mmc/host/mmci.h |  8 ++++++++
 2 files changed, 51 insertions(+), 4 deletions(-)
diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 801c86b..52562fc 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -51,6 +51,10 @@ static unsigned int fmax = 515633;
 static struct variant_data variant_arm = {
        .fifosize               = 16 * 4,
        .fifohalfsize           = 8 * 4,
+       .cmdreg_cpsm_enable     = MCI_CPSM_ENABLE,
+       .cmdreg_lrsp_crc        = MCI_CPSM_RESPONSE | MCI_CPSM_LONGRSP,
+       .cmdreg_srsp_crc        = MCI_CPSM_RESPONSE,
+       .cmdreg_srsp            = MCI_CPSM_RESPONSE,
Do these really needs to be a superset of each other?

Maybe it becomes easier for the STM32 variant later though...

[...]
quoted hunk ↗ jump to hunk
@@ -603,16 +639,19 @@ mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c)
While at it, would you mind folding in a cleanup patch removing the
"u32 c" as in-parameter? It's currently always set to "0" by the
caller, so it's not needed.
        dev_dbg(mmc_dev(host->mmc), "op %02x arg %08x flags %08x\n",
            cmd->opcode, cmd->arg, cmd->flags);

-       if (readl(base + MMCICOMMAND) & MCI_CPSM_ENABLE) {
+       if (readl(base + MMCICOMMAND) & host->variant->cmdreg_cpsm_enable) {
                writel(0, base + MMCICOMMAND);
                mmci_reg_delay(host);
        }

-       c |= cmd->opcode | MCI_CPSM_ENABLE;
+       c |= cmd->opcode | host->variant->cmdreg_cpsm_enable;
        if (cmd->flags & MMC_RSP_PRESENT) {
                if (cmd->flags & MMC_RSP_136)
-                       c |= MCI_CPSM_LONGRSP;
-               c |= MCI_CPSM_RESPONSE;
+                       c |= host->variant->cmdreg_lrsp_crc;
This looks weird. Probably because of the naming of the variant data.

Perhaps rename to "cmdreg_lrsp", thus skipping the "_crc" suffix?
+               else if (cmd->flags & MMC_RSP_CRC)
+                       c |= host->variant->cmdreg_srsp_crc;
Why is here an else? We can have both MMC_RSP_136 and MMC_RSP_CRC bits
set, right!?
+               else
+                       c |= host->variant->cmdreg_srsp;
What do you think about using a switch-case, perhaps with fall-through
- and then adding those bits that are needed for each response
bit+variant instead? Could that make this more readable?
quoted hunk ↗ jump to hunk
        }
        if (/*interrupt*/0)
                c |= MCI_CPSM_INTERRUPT;
diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
index 7265ca6..e173305 100644
--- a/drivers/mmc/host/mmci.h
+++ b/drivers/mmc/host/mmci.h
@@ -239,6 +239,10 @@ struct mmci_host;
  * @clkreg_enable: enable value for MMCICLOCK register
  * @clkreg_8bit_bus_enable: enable value for 8 bit bus
  * @clkreg_neg_edge_enable: enable value for inverted data/cmd output
+ * @cmdreg_cpsm_enable: enable value for CPSM
+ * @cmdreg_lrsp_crc: enable value for long response with crc
+ * @cmdreg_srsp_crc: enable value for short response with crc
+ * @cmdreg_srsp: enable value for short response without crc
  * @datalength_bits: number of bits in the MMCIDATALENGTH register
  * @fifosize: number of bytes that can be written when MMCI_TXFIFOEMPTY
  *           is asserted (likewise for RX)
@@ -282,6 +286,10 @@ struct variant_data {
        unsigned int            clkreg_enable;
        unsigned int            clkreg_8bit_bus_enable;
        unsigned int            clkreg_neg_edge_enable;
+       unsigned int            cmdreg_cpsm_enable;
+       unsigned int            cmdreg_lrsp_crc;
+       unsigned int            cmdreg_srsp_crc;
+       unsigned int            cmdreg_srsp;
        unsigned int            datalength_bits;
        unsigned int            fifosize;
        unsigned int            fifohalfsize;
--
2.7.4
Kind regards
Uffe
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help