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From:   Ludovic Barre <ludovic.Barre@st.com>
To:     Ulf Hansson <ulf.hansson@linaro.org>,
        Rob Herring <robh+dt@kernel.org>
CC:     Maxime Coquelin <mcoquelin.stm32@gmail.com>,
        Alexandre Torgue <alexandre.torgue@st.com>,
        Gerald Baeza <gerald.baeza@st.com>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>, <devicetree@vger.kernel.org>,
        <linux-mmc@vger.kernel.org>, Ludovic Barre <ludovic.barre@st.com>
Subject: [PATCH 10/19] mmc: mmci: add variant property to allow remain data
Date:   Tue, 12 Jun 2018 15:14:31 +0200
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From: Ludovic Barre <ludovic.barre@st.com>

This patch adds a boolean property to read remaining data.
Needed to support the STM32 sdmmc variant. MMCIDATACNT
register should be read only after the data transfer is complete.
When reading after an error event the read data count value may be
different from the real number of data bytes transferred.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
---
 drivers/mmc/host/mmci.c | 17 +++++++++++++++--
 drivers/mmc/host/mmci.h |  3 +++
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 83c3572..abddad7 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -58,6 +58,7 @@ static struct variant_data variant_arm = {
 	.datalength_bits	= 16,
 	.datactrl_blocksz	= 11,
 	.datactrl_dpsm_enable	= MCI_DPSM_ENABLE,
+	.datacnt_remain		= true,
 	.pwrreg_powerup		= MCI_PWR_UP,
 	.f_max			= 100000000,
 	.reversed_irq_handling	= true,
@@ -78,6 +79,7 @@ static struct variant_data variant_arm_extended_fifo = {
 	.datalength_bits	= 16,
 	.datactrl_blocksz	= 11,
 	.datactrl_dpsm_enable	= MCI_DPSM_ENABLE,
+	.datacnt_remain		= true,
 	.pwrreg_powerup		= MCI_PWR_UP,
 	.f_max			= 100000000,
 	.mmcimask1		= true,
@@ -98,6 +100,7 @@ static struct variant_data variant_arm_extended_fifo_hwfc = {
 	.datalength_bits	= 16,
 	.datactrl_blocksz	= 11,
 	.datactrl_dpsm_enable	= MCI_DPSM_ENABLE,
+	.datacnt_remain		= true,
 	.pwrreg_powerup		= MCI_PWR_UP,
 	.f_max			= 100000000,
 	.mmcimask1		= true,
@@ -120,6 +123,7 @@ static struct variant_data variant_u300 = {
 	.datactrl_blocksz	= 11,
 	.datactrl_dpsm_enable	= MCI_DPSM_ENABLE,
 	.datactrl_mask_sdio	= MCI_DPSM_ST_SDIOEN,
+	.datacnt_remain		= true,
 	.st_sdio			= true,
 	.pwrreg_powerup		= MCI_PWR_ON,
 	.f_max			= 100000000,
@@ -146,6 +150,7 @@ static struct variant_data variant_nomadik = {
 	.datactrl_blocksz	= 11,
 	.datactrl_dpsm_enable	= MCI_DPSM_ENABLE,
 	.datactrl_mask_sdio	= MCI_DPSM_ST_SDIOEN,
+	.datacnt_remain		= true,
 	.st_sdio		= true,
 	.st_clkdiv		= true,
 	.pwrreg_powerup		= MCI_PWR_ON,
@@ -175,6 +180,7 @@ static struct variant_data variant_ux500 = {
 	.datactrl_blocksz	= 11,
 	.datactrl_dpsm_enable	= MCI_DPSM_ENABLE,
 	.datactrl_mask_sdio	= MCI_DPSM_ST_SDIOEN,
+	.datacnt_remain		= true,
 	.st_sdio		= true,
 	.st_clkdiv		= true,
 	.pwrreg_powerup		= MCI_PWR_ON,
@@ -209,6 +215,7 @@ static struct variant_data variant_ux500v2 = {
 	.datactrl_blocksz	= 11,
 	.datactrl_dpsm_enable	= MCI_DPSM_ENABLE,
 	.datactrl_mask_sdio	= MCI_DPSM_ST_SDIOEN,
+	.datacnt_remain		= true,
 	.st_sdio		= true,
 	.st_clkdiv		= true,
 	.blksz_datactrl16	= true,
@@ -244,6 +251,7 @@ static struct variant_data variant_stm32 = {
 	.datactrl_blocksz	= 11,
 	.datactrl_dpsm_enable	= MCI_DPSM_ENABLE,
 	.datactrl_mask_sdio	= MCI_DPSM_ST_SDIOEN,
+	.datacnt_remain		= true,
 	.st_sdio		= true,
 	.st_clkdiv		= true,
 	.pwrreg_powerup		= MCI_PWR_ON,
@@ -270,6 +278,7 @@ static struct variant_data variant_qcom = {
 	.datalength_bits	= 24,
 	.datactrl_blocksz	= 11,
 	.datactrl_dpsm_enable	= MCI_DPSM_ENABLE,
+	.datacnt_remain		= true,
 	.pwrreg_powerup		= MCI_PWR_UP,
 	.f_max			= 208000000,
 	.explicit_mclk_control	= true,
@@ -711,8 +720,12 @@ mmci_data_irq(struct mmci_host *host, struct mmc_data *data,
 		 * can be as much as a FIFO-worth of data ahead.  This
 		 * matters for FIFO overruns only.
 		 */
-		remain = readl(host->base + MMCIDATACNT);
-		success = data->blksz * data->blocks - remain;
+		if (host->variant->datacnt_remain) {
+			remain = readl(host->base + MMCIDATACNT);
+			success = data->blksz * data->blocks - remain;
+		} else {
+			success = 0;
+		}
 
 		dev_dbg(mmc_dev(host->mmc), "MCI ERROR IRQ, status 0x%08x at 0x%08x\n",
 			status_err, success);
diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
index 5091025..12ee2e6 100644
--- a/drivers/mmc/host/mmci.h
+++ b/drivers/mmc/host/mmci.h
@@ -260,6 +260,8 @@ struct mmci_host;
  * @datactrl_blksz: block size in power of two
  * @datactrl_dpsm_enable: enable value for DPSM
  * @datactrl_first: true if data must be setup before send command
+ * @datacnt_remain: true if you could read datacnt register
+ *                  to define remain data
  * @pwrreg_powerup: power up value for MMCIPOWER register
  * @f_max: maximum clk frequency supported by the controller.
  * @signal_direction: input/out direction of bus signals can be indicated
@@ -303,6 +305,7 @@ struct variant_data {
 	unsigned int		datactrl_blocksz;
 	unsigned int		datactrl_dpsm_enable;
 	bool			datactrl_first;
+	bool			datacnt_remain;
 	bool			st_sdio;
 	bool			st_clkdiv;
 	bool			blksz_datactrl16;
-- 
2.7.4