[PATCH v23 09/14] mmc: renesas_sdhi: Add write32_hook for CTL_SD_CARD_CLK_CTL register writes

From: Biju Das <[email protected]>

Add a write32_hook, analogous to the existing write16_hook, so that
sd_ctrl_write32() can wait for the SD bus to become idle before
certain 32-bit register writes.

renesas_sdhi_write32_hook() checks whether the target register is
CTL_SD_CARD_CLK_CTL and, if so, waits for TMIO_STAT_SCLKDIVEN via
renesas_sdhi_wait_idle() before the write proceeds. Other registers
are unaffected. As with write16_hook, the write is skipped if the
hook returns a non-zero error.

Signed-off-by: Biju Das <[email protected]>
---
v23:
 * New patch.
---
 drivers/mmc/host/renesas_sdhi_core.c | 9 +++++++++
 drivers/mmc/host/tmio_mmc.h          | 7 +++++++
 2 files changed, 16 insertions(+)

diff --git a/drivers/mmc/host/renesas_sdhi_core.c b/drivers/mmc/host/renesas_sdhi_core.c
index ebbce7f010be..ba109a15b47b 100644
--- a/drivers/mmc/host/renesas_sdhi_core.c
+++ b/drivers/mmc/host/renesas_sdhi_core.c
@@ -969,6 +969,14 @@ static int renesas_sdhi_write16_hook(struct tmio_mmc_host *host, int addr)
 	return 0;
 }
 
+static int renesas_sdhi_write32_hook(struct tmio_mmc_host *host, int addr)
+{
+	if (addr == CTL_SD_CARD_CLK_CTL)
+		return renesas_sdhi_wait_idle(host, TMIO_STAT_SCLKDIVEN);
+
+	return 0;
+}
+
 static int renesas_sdhi_multi_io_quirk(struct mmc_card *card,
 				       unsigned int direction, int blk_size)
 {
@@ -1203,6 +1211,7 @@ int renesas_sdhi_probe(struct platform_device *pdev,
 	}
 
 	host->write16_hook = renesas_sdhi_write16_hook;
+	host->write32_hook = renesas_sdhi_write32_hook;
 	host->clk_enable = renesas_sdhi_clk_enable;
 	host->clk_disable = renesas_sdhi_clk_disable;
 	host->set_clock = renesas_sdhi_set_clock;
diff --git a/drivers/mmc/host/tmio_mmc.h b/drivers/mmc/host/tmio_mmc.h
index b9de03325c58..8d6d65a51be7 100644
--- a/drivers/mmc/host/tmio_mmc.h
+++ b/drivers/mmc/host/tmio_mmc.h
@@ -190,6 +190,7 @@ struct tmio_mmc_host {
 	int (*multi_io_quirk)(struct mmc_card *card,
 			      unsigned int direction, int blk_size);
 	int (*write16_hook)(struct tmio_mmc_host *host, int addr);
+	int (*write32_hook)(struct tmio_mmc_host *host, int addr);
 	void (*reset)(struct tmio_mmc_host *host, bool preserve);
 	bool (*check_retune)(struct tmio_mmc_host *host, struct mmc_request *mrq);
 	void (*fixup_request)(struct tmio_mmc_host *host, struct mmc_request *mrq);
@@ -284,6 +285,12 @@ static inline void sd_ctrl_write32_as_16_and_16(struct tmio_mmc_host *host,
 
 static inline void sd_ctrl_write32(struct tmio_mmc_host *host, int addr, u32 val)
 {
+	/* If there is a hook and it returns non-zero then there
+	 * is an error and the write should be skipped
+	 */
+	if (host->write32_hook && host->write32_hook(host, addr))
+		return;
+
 	iowrite32(val, host->ctl + (addr << host->bus_shift));
 }
 
-- 
2.43.0