[PATCH/RFC v2 0/5] mmc: renesas_sdhi: add R-Car Gen-3 DMA support

[PATCH/RFC v2 0/5] mmc: renesas_sdhi: add R-Car Gen-3 DMA support

[Simon Horman]

Hi,

this short series adds support for R-Car Gen-3 Internal DMAC to the SDHI
driver.

The approach taken is as follows:

1. Refactor the TMIO DMA code so that it is provided by a set of callbacks
   rather than compiled-in function calls; Refactor the DMA SDHI to use
   this.
2. Rename tmio_mmc_dma.c as renesas_sdhi_sysc_dmac.c which better reflects
   what it is is, particularly after step 2.
3. Add max_segs restriction
4. Add Gen3 DMA code as a separate set of callbacks

Changes since v3:
* Cleanup and more renaming as suggested by Wolfram Sang
* max_segs restriction

Testing:

As described on http://elinux.org/Tests:r-car-gen3-sdhi-dma

Performance appears to be less than expected,
4.7Mb/s read for a card observed to read at 20Mb/s on r8a7790/Koelsch.

I will inviestigate this further.


Simon Horman (2):
  mmc: sh_mobile_sdhi, tmio: make dma more modular
  mmc: sh_mobile_sdhi: rename DMA source file as
    renesas_sdhi_sysc_dmac.c

Yoshihiro Shimoda (3):
  mmc: tmio: add max_segs and max_blk_count in tmio_mmc_data
  mmc: sh_mobile_sdhi: add some SoC specific data for R-Car Gen3
  mmc: renesas_sdhi: add support for R-Car Gen3 SDHI DMAC

 drivers/mmc/host/Kconfig                           |  18 ++
 drivers/mmc/host/Makefile                          |   7 +-
 drivers/mmc/host/renesas_sdhi_internal_dmac.c      | 192 +++++++++++++++++++++
 .../{tmio_mmc_dma.c => renesas_sdhi_sysc_dmac.c}   |  55 ++++--
 drivers/mmc/host/sh_mobile_sdhi.c                  |  49 ++++++
 drivers/mmc/host/tmio_mmc.h                        |  39 +----
 drivers/mmc/host/tmio_mmc_pio.c                    |  49 +++++-
 include/linux/mfd/tmio.h                           |   2 +
 8 files changed, 360 insertions(+), 51 deletions(-)
 create mode 100644 drivers/mmc/host/renesas_sdhi_internal_dmac.c
 rename drivers/mmc/host/{tmio_mmc_dma.c => renesas_sdhi_sysc_dmac.c} (83%)

-- 
2.7.0.rc3.207.g0ac5344

[PATCH/RFC v2 1/5] mmc: sh_mobile_sdhi, tmio: make dma more modular

[Simon Horman]

Refactor DMA support to allow it to be provided by a set of call-backs
that are provided by a host driver. The motivation is to allow multiple
DMA implementations to be provided and instantiated at run-time.

Instantiate the existing DMA implementation from the sh_mobile_sdhi driver
which appears to match the current use-case. This has the side effect
of moving the DMA code from the tmio_core to the sh_mobile_sdhi driver.

A follow-up patch will change the source file for the SDHI DMA
implementation accordingly.

Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
---
v2
* Fix compilation issue due to error in Makefile
* Use MMC_SDHI_SYSC_DMA rather than MMC_SDHI_DMA as new Kconfig symbole
  to better reflect revamped file rename in a follow-up patch.

Todo: Investigate removing ifdef
---
 drivers/mmc/host/Kconfig          |  9 ++++++++
 drivers/mmc/host/Makefile         |  4 +++-
 drivers/mmc/host/sh_mobile_sdhi.c | 13 +++++++++++
 drivers/mmc/host/tmio_mmc.h       | 39 ++++++++------------------------
 drivers/mmc/host/tmio_mmc_dma.c   | 26 +++++++++++++++++-----
 drivers/mmc/host/tmio_mmc_pio.c   | 47 +++++++++++++++++++++++++++++++++++++++
 6 files changed, 102 insertions(+), 36 deletions(-)

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 5274f503a39a..a0b6c1773e33 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -554,10 +554,19 @@ config MMC_SDHI
 	depends on SUPERH || ARM || ARM64
 	depends on SUPERH || ARCH_RENESAS || COMPILE_TEST
 	select MMC_TMIO_CORE
+	select MMC_SDHI_SYSC_DMA if (SUPERH || ARM)
 	help
 	  This provides support for the SDHI SD/SDIO controller found in
 	  SuperH and ARM SH-Mobile SoCs
 
+config MMC_SDHI_SYSC_DMA
+	tristate "DMA support use of SYSC DMAC with SDHI SD/SDIO controller"
+	depends on SUPERH || ARM || COMPILE_TEST
+	depends on MMC_SDHI
+	help
+	  This provides DMA support for the SDHI SD/SDIO controller
+	  found in SuperH and Renesas ARM based SoCs.
+
 config MMC_CB710
 	tristate "ENE CB710 MMC/SD Interface support"
 	depends on PCI
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index e2bdaaf43184..4ed6f250213a 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -37,8 +37,10 @@ obj-$(CONFIG_MMC_SDRICOH_CS)	+= sdricoh_cs.o
 obj-$(CONFIG_MMC_TMIO)		+= tmio_mmc.o
 obj-$(CONFIG_MMC_TMIO_CORE)	+= tmio_mmc_core.o
 tmio_mmc_core-y			:= tmio_mmc_pio.o
-tmio_mmc_core-$(subst m,y,$(CONFIG_MMC_SDHI))	+= tmio_mmc_dma.o
 obj-$(CONFIG_MMC_SDHI)		+= sh_mobile_sdhi.o
+ifeq ($(subst m,y,$(CONFIG_MMC_SDHI_SYSC_DMA)),y)
+obj-$(CONFIG_MMC_SDHI)		+= tmio_mmc_dma.o
+endif
 obj-$(CONFIG_MMC_CB710)		+= cb710-mmc.o
 obj-$(CONFIG_MMC_VIA_SDMMC)	+= via-sdmmc.o
 obj-$(CONFIG_SDH_BFIN)		+= bfin_sdh.o
diff --git a/drivers/mmc/host/sh_mobile_sdhi.c b/drivers/mmc/host/sh_mobile_sdhi.c
index c3b651bf89cb..45543ed37e5f 100644
--- a/drivers/mmc/host/sh_mobile_sdhi.c
+++ b/drivers/mmc/host/sh_mobile_sdhi.c
@@ -106,6 +106,15 @@ struct sh_mobile_sdhi {
 	struct pinctrl_state *pins_default, *pins_uhs;
 };
 
+#if IS_ENABLED(MMC_SDHI_SYSC_DMA)
+int tmio_mmc_init_dma(void);
+#else
+static int tmio_mmc_init_dma(void)
+{
+       return -EINVAL;
+}
+#endif
+
 static void sh_mobile_sdhi_sdbuf_width(struct tmio_mmc_host *host, int width)
 {
 	u32 val;
@@ -363,6 +372,10 @@ static int sh_mobile_sdhi_probe(struct platform_device *pdev)
 		host->bus_shift = of_data->bus_shift;
 	}
 
+	ret = tmio_mmc_init_dma();
+	if (ret < 0)
+		goto efree;
+
 	host->dma		= dma_priv;
 	host->write16_hook	= sh_mobile_sdhi_write16_hook;
 	host->clk_enable	= sh_mobile_sdhi_clk_enable;
diff --git a/drivers/mmc/host/tmio_mmc.h b/drivers/mmc/host/tmio_mmc.h
index 7f63ec05bdf4..cbe0212fbbf4 100644
--- a/drivers/mmc/host/tmio_mmc.h
+++ b/drivers/mmc/host/tmio_mmc.h
@@ -187,37 +187,16 @@ static inline void tmio_mmc_kunmap_atomic(struct scatterlist *sg,
 	local_irq_restore(*flags);
 }
 
-#if defined(CONFIG_MMC_SDHI) || defined(CONFIG_MMC_SDHI_MODULE)
-void tmio_mmc_start_dma(struct tmio_mmc_host *host, struct mmc_data *data);
-void tmio_mmc_enable_dma(struct tmio_mmc_host *host, bool enable);
-void tmio_mmc_request_dma(struct tmio_mmc_host *host, struct tmio_mmc_data *pdata);
-void tmio_mmc_release_dma(struct tmio_mmc_host *host);
-void tmio_mmc_abort_dma(struct tmio_mmc_host *host);
-#else
-static inline void tmio_mmc_start_dma(struct tmio_mmc_host *host,
-			       struct mmc_data *data)
-{
-}
-
-static inline void tmio_mmc_enable_dma(struct tmio_mmc_host *host, bool enable)
-{
-}
-
-static inline void tmio_mmc_request_dma(struct tmio_mmc_host *host,
-				 struct tmio_mmc_data *pdata)
-{
-	host->chan_tx = NULL;
-	host->chan_rx = NULL;
-}
-
-static inline void tmio_mmc_release_dma(struct tmio_mmc_host *host)
-{
-}
+struct tmio_mmc_dma_ops {
+	void (*start)(struct tmio_mmc_host *host, struct mmc_data *data);
+	void (*enable)(struct tmio_mmc_host *host, bool enable);
+	void (*request)(struct tmio_mmc_host *host,
+			struct tmio_mmc_data *pdata);
+	void (*release)(struct tmio_mmc_host *host);
+	void (*abort)(struct tmio_mmc_host *host);
+};
 
-static inline void tmio_mmc_abort_dma(struct tmio_mmc_host *host)
-{
-}
-#endif
+void tmio_set_dma_ops(const struct tmio_mmc_dma_ops *ops);
 
 #ifdef CONFIG_PM
 int tmio_mmc_host_runtime_suspend(struct device *dev);
diff --git a/drivers/mmc/host/tmio_mmc_dma.c b/drivers/mmc/host/tmio_mmc_dma.c
index fa8a936a3d9b..381bc40e506b 100644
--- a/drivers/mmc/host/tmio_mmc_dma.c
+++ b/drivers/mmc/host/tmio_mmc_dma.c
@@ -22,7 +22,7 @@
 
 #define TMIO_MMC_MIN_DMA_LEN 8
 
-void tmio_mmc_enable_dma(struct tmio_mmc_host *host, bool enable)
+static void tmio_mmc_enable_dma(struct tmio_mmc_host *host, bool enable)
 {
 	if (!host->chan_tx || !host->chan_rx)
 		return;
@@ -31,7 +31,7 @@ void tmio_mmc_enable_dma(struct tmio_mmc_host *host, bool enable)
 		host->dma->enable(host, enable);
 }
 
-void tmio_mmc_abort_dma(struct tmio_mmc_host *host)
+static void tmio_mmc_abort_dma(struct tmio_mmc_host *host)
 {
 	tmio_mmc_enable_dma(host, false);
 
@@ -187,7 +187,7 @@ pio:
 	}
 }
 
-void tmio_mmc_start_dma(struct tmio_mmc_host *host,
+static void tmio_mmc_start_dma(struct tmio_mmc_host *host,
 			       struct mmc_data *data)
 {
 	if (data->flags & MMC_DATA_READ) {
@@ -244,7 +244,8 @@ out:
 	spin_unlock_irq(&host->lock);
 }
 
-void tmio_mmc_request_dma(struct tmio_mmc_host *host, struct tmio_mmc_data *pdata)
+static void tmio_mmc_request_dma(struct tmio_mmc_host *host,
+				 struct tmio_mmc_data *pdata)
 {
 	/* We can only either use DMA for both Tx and Rx or not use it at all */
 	if (!host->dma || (!host->pdev->dev.of_node &&
@@ -324,7 +325,7 @@ ecfgtx:
 	host->chan_tx = NULL;
 }
 
-void tmio_mmc_release_dma(struct tmio_mmc_host *host)
+static void tmio_mmc_release_dma(struct tmio_mmc_host *host)
 {
 	if (host->chan_tx) {
 		struct dma_chan *chan = host->chan_tx;
@@ -341,3 +342,18 @@ void tmio_mmc_release_dma(struct tmio_mmc_host *host)
 		host->bounce_buf = NULL;
 	}
 }
+
+static struct tmio_mmc_dma_ops tmio_mmc_dma_ops __initdata = {
+	.start = tmio_mmc_start_dma,
+	.enable = tmio_mmc_enable_dma,
+	.request = tmio_mmc_request_dma,
+	.release = tmio_mmc_release_dma,
+	.abort = tmio_mmc_abort_dma,
+};
+
+int tmio_mmc_init_dma(void)
+{
+	tmio_set_dma_ops(&tmio_mmc_dma_ops);
+
+	return 0;
+}
diff --git a/drivers/mmc/host/tmio_mmc_pio.c b/drivers/mmc/host/tmio_mmc_pio.c
index 92467efc4e2c..c0020c331595 100644
--- a/drivers/mmc/host/tmio_mmc_pio.c
+++ b/drivers/mmc/host/tmio_mmc_pio.c
@@ -52,17 +52,63 @@
 
 #include "tmio_mmc.h"
 
+static struct tmio_mmc_dma_ops tmio_dma_ops;
+
+void tmio_set_dma_ops(const struct tmio_mmc_dma_ops *ops)
+{
+	tmio_dma_ops = *ops;
+}
+EXPORT_SYMBOL(tmio_set_dma_ops);
+
+static inline void tmio_mmc_start_dma(struct tmio_mmc_host *host,
+				      struct mmc_data *data)
+{
+	if (tmio_dma_ops.start)
+		tmio_dma_ops.start(host, data);
+}
+
+static inline void tmio_mmc_enable_dma(struct tmio_mmc_host *host, bool enable)
+{
+	if (tmio_dma_ops.enable)
+		tmio_dma_ops.enable(host, enable);
+}
+
+static inline void tmio_mmc_request_dma(struct tmio_mmc_host *host,
+					struct tmio_mmc_data *pdata)
+{
+	if (tmio_dma_ops.request) {
+		tmio_dma_ops.request(host, pdata);
+	} else {
+		host->chan_tx = NULL;
+		host->chan_rx = NULL;
+	}
+}
+
+static inline void tmio_mmc_release_dma(struct tmio_mmc_host *host)
+{
+	if (tmio_dma_ops.release)
+		tmio_dma_ops.release(host);
+}
+
+static inline void tmio_mmc_abort_dma(struct tmio_mmc_host *host)
+{
+	if (tmio_dma_ops.abort)
+		tmio_dma_ops.abort(host);
+}
+
 void tmio_mmc_enable_mmc_irqs(struct tmio_mmc_host *host, u32 i)
 {
 	host->sdcard_irq_mask &= ~(i & TMIO_MASK_IRQ);
 	sd_ctrl_write32_as_16_and_16(host, CTL_IRQ_MASK, host->sdcard_irq_mask);
 }
+EXPORT_SYMBOL(tmio_mmc_enable_mmc_irqs);
 
 void tmio_mmc_disable_mmc_irqs(struct tmio_mmc_host *host, u32 i)
 {
 	host->sdcard_irq_mask |= (i & TMIO_MASK_IRQ);
 	sd_ctrl_write32_as_16_and_16(host, CTL_IRQ_MASK, host->sdcard_irq_mask);
 }
+EXPORT_SYMBOL(tmio_mmc_disable_mmc_irqs);
 
 static void tmio_mmc_ack_mmc_irqs(struct tmio_mmc_host *host, u32 i)
 {
@@ -519,6 +565,7 @@ void tmio_mmc_do_data_irq(struct tmio_mmc_host *host)
 
 	schedule_work(&host->done);
 }
+EXPORT_SYMBOL(tmio_mmc_do_data_irq);
 
 static void tmio_mmc_data_irq(struct tmio_mmc_host *host)
 {
-- 
2.7.0.rc3.207.g0ac5344

[PATCH/RFC v2 2/5] mmc: sh_mobile_sdhi: rename DMA source file as renesas_sdhi_sysc_dmac.c

[Simon Horman]

Rename the source file for DMA for SDHI as a follow-up to attaching
DMA code to the SDHI driver rather than the tmio_core driver and
prepartation for allowing more than one DMA provider.

The name Renesas is chosen as the the SDHI driver is applicable to a wider
range of SoCs than SH-Mobile, Renesas seems to be a more appropriate name.
However, the SDHI driver source itself, is left as sh_mobile_sdhi to
avoid unnecessary churn.

The name sysc_dmac was chosen to reflect the type of DMA used.

Internal symbols have also been renamed to reflect the filename change.

Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
---
v2
* Use renesas_sdhi_sysc_dmac rather than renesas_sdhi_dmac as file name
* Rename symbols to reflect filename change
* Drop bogus use of __initdata
---
 drivers/mmc/host/Makefile                          |  2 +-
 .../{tmio_mmc_dma.c => renesas_sdhi_sysc_dmac.c}   | 57 +++++++++++-----------
 drivers/mmc/host/sh_mobile_sdhi.c                  |  6 +--
 3 files changed, 33 insertions(+), 32 deletions(-)
 rename drivers/mmc/host/{tmio_mmc_dma.c => renesas_sdhi_sysc_dmac.c} (83%)

diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index 4ed6f250213a..da5377e3ee4e 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -39,7 +39,7 @@ obj-$(CONFIG_MMC_TMIO_CORE)	+= tmio_mmc_core.o
 tmio_mmc_core-y			:= tmio_mmc_pio.o
 obj-$(CONFIG_MMC_SDHI)		+= sh_mobile_sdhi.o
 ifeq ($(subst m,y,$(CONFIG_MMC_SDHI_SYSC_DMA)),y)
-obj-$(CONFIG_MMC_SDHI)		+= tmio_mmc_dma.o
+obj-$(CONFIG_MMC_SDHI)		+= renesas_sdhi_sysc_dmac.o
 endif
 obj-$(CONFIG_MMC_CB710)		+= cb710-mmc.o
 obj-$(CONFIG_MMC_VIA_SDMMC)	+= via-sdmmc.o
diff --git a/drivers/mmc/host/tmio_mmc_dma.c b/drivers/mmc/host/renesas_sdhi_sysc_dmac.c
similarity index 83%
rename from drivers/mmc/host/tmio_mmc_dma.c
rename to drivers/mmc/host/renesas_sdhi_sysc_dmac.c
index 381bc40e506b..a73055924c52 100644
--- a/drivers/mmc/host/tmio_mmc_dma.c
+++ b/drivers/mmc/host/renesas_sdhi_sysc_dmac.c
@@ -1,5 +1,5 @@
 /*
- * linux/drivers/mmc/tmio_mmc_dma.c
+ * linux/drivers/mmc/renesas_sdhi_sysc_dmac_dma.c
  *
  * Copyright (C) 2010-2011 Guennadi Liakhovetski
  *
@@ -22,7 +22,8 @@
 
 #define TMIO_MMC_MIN_DMA_LEN 8
 
-static void tmio_mmc_enable_dma(struct tmio_mmc_host *host, bool enable)
+static void sdhi_sysc_dmac_enable_dma(struct tmio_mmc_host *host,
+				      bool enable)
 {
 	if (!host->chan_tx || !host->chan_rx)
 		return;
@@ -31,19 +32,19 @@ static void tmio_mmc_enable_dma(struct tmio_mmc_host *host, bool enable)
 		host->dma->enable(host, enable);
 }
 
-static void tmio_mmc_abort_dma(struct tmio_mmc_host *host)
+static void sdhi_sysc_dmac_abort_dma(struct tmio_mmc_host *host)
 {
-	tmio_mmc_enable_dma(host, false);
+	sdhi_sysc_dmac_enable_dma(host, false);
 
 	if (host->chan_rx)
 		dmaengine_terminate_all(host->chan_rx);
 	if (host->chan_tx)
 		dmaengine_terminate_all(host->chan_tx);
 
-	tmio_mmc_enable_dma(host, true);
+	sdhi_sysc_dmac_enable_dma(host, true);
 }
 
-static void tmio_mmc_start_dma_rx(struct tmio_mmc_host *host)
+static void sdhi_sysc_dmac_start_dma_rx(struct tmio_mmc_host *host)
 {
 	struct scatterlist *sg = host->sg_ptr, *sg_tmp;
 	struct dma_async_tx_descriptor *desc = NULL;
@@ -97,7 +98,7 @@ static void tmio_mmc_start_dma_rx(struct tmio_mmc_host *host)
 pio:
 	if (!desc) {
 		/* DMA failed, fall back to PIO */
-		tmio_mmc_enable_dma(host, false);
+		sdhi_sysc_dmac_enable_dma(host, false);
 		if (ret >= 0)
 			ret = -EIO;
 		host->chan_rx = NULL;
@@ -113,7 +114,7 @@ pio:
 	}
 }
 
-static void tmio_mmc_start_dma_tx(struct tmio_mmc_host *host)
+static void sdhi_sysc_dmac_start_dma_tx(struct tmio_mmc_host *host)
 {
 	struct scatterlist *sg = host->sg_ptr, *sg_tmp;
 	struct dma_async_tx_descriptor *desc = NULL;
@@ -171,7 +172,7 @@ static void tmio_mmc_start_dma_tx(struct tmio_mmc_host *host)
 pio:
 	if (!desc) {
 		/* DMA failed, fall back to PIO */
-		tmio_mmc_enable_dma(host, false);
+		sdhi_sysc_dmac_enable_dma(host, false);
 		if (ret >= 0)
 			ret = -EIO;
 		host->chan_tx = NULL;
@@ -187,19 +188,19 @@ pio:
 	}
 }
 
-static void tmio_mmc_start_dma(struct tmio_mmc_host *host,
+static void sdhi_sysc_dmac_start_dma(struct tmio_mmc_host *host,
 			       struct mmc_data *data)
 {
 	if (data->flags & MMC_DATA_READ) {
 		if (host->chan_rx)
-			tmio_mmc_start_dma_rx(host);
+			sdhi_sysc_dmac_start_dma_rx(host);
 	} else {
 		if (host->chan_tx)
-			tmio_mmc_start_dma_tx(host);
+			sdhi_sysc_dmac_start_dma_tx(host);
 	}
 }
 
-static void tmio_mmc_issue_tasklet_fn(unsigned long priv)
+static void sdhi_sysc_dmac_issue_tasklet_fn(unsigned long priv)
 {
 	struct tmio_mmc_host *host = (struct tmio_mmc_host *)priv;
 	struct dma_chan *chan = NULL;
@@ -221,7 +222,7 @@ static void tmio_mmc_issue_tasklet_fn(unsigned long priv)
 		dma_async_issue_pending(chan);
 }
 
-static void tmio_mmc_tasklet_fn(unsigned long arg)
+static void sdhi_sysc_dmac_tasklet_fn(unsigned long arg)
 {
 	struct tmio_mmc_host *host = (struct tmio_mmc_host *)arg;
 
@@ -244,8 +245,8 @@ out:
 	spin_unlock_irq(&host->lock);
 }
 
-static void tmio_mmc_request_dma(struct tmio_mmc_host *host,
-				 struct tmio_mmc_data *pdata)
+static void sdhi_sysc_dmac_request_dma(struct tmio_mmc_host *host,
+				       struct tmio_mmc_data *pdata)
 {
 	/* We can only either use DMA for both Tx and Rx or not use it at all */
 	if (!host->dma || (!host->pdev->dev.of_node &&
@@ -307,11 +308,11 @@ static void tmio_mmc_request_dma(struct tmio_mmc_host *host,
 		if (!host->bounce_buf)
 			goto ebouncebuf;
 
-		tasklet_init(&host->dma_complete, tmio_mmc_tasklet_fn, (unsigned long)host);
-		tasklet_init(&host->dma_issue, tmio_mmc_issue_tasklet_fn, (unsigned long)host);
+		tasklet_init(&host->dma_complete, sdhi_sysc_dmac_tasklet_fn, (unsigned long)host);
+		tasklet_init(&host->dma_issue, sdhi_sysc_dmac_issue_tasklet_fn, (unsigned long)host);
 	}
 
-	tmio_mmc_enable_dma(host, true);
+	sdhi_sysc_dmac_enable_dma(host, true);
 
 	return;
 
@@ -325,7 +326,7 @@ ecfgtx:
 	host->chan_tx = NULL;
 }
 
-static void tmio_mmc_release_dma(struct tmio_mmc_host *host)
+static void sdhi_sysc_dmac_release_dma(struct tmio_mmc_host *host)
 {
 	if (host->chan_tx) {
 		struct dma_chan *chan = host->chan_tx;
@@ -343,17 +344,17 @@ static void tmio_mmc_release_dma(struct tmio_mmc_host *host)
 	}
 }
 
-static struct tmio_mmc_dma_ops tmio_mmc_dma_ops __initdata = {
-	.start = tmio_mmc_start_dma,
-	.enable = tmio_mmc_enable_dma,
-	.request = tmio_mmc_request_dma,
-	.release = tmio_mmc_release_dma,
-	.abort = tmio_mmc_abort_dma,
+static struct tmio_mmc_dma_ops sdhi_sysc_dmac_dma_ops = {
+	.start = sdhi_sysc_dmac_start_dma,
+	.enable = sdhi_sysc_dmac_enable_dma,
+	.request = sdhi_sysc_dmac_request_dma,
+	.release = sdhi_sysc_dmac_release_dma,
+	.abort = sdhi_sysc_dmac_abort_dma,
 };
 
-int tmio_mmc_init_dma(void)
+int sdhi_sysc_dmac_init_dma(void)
 {
-	tmio_set_dma_ops(&tmio_mmc_dma_ops);
+	tmio_set_dma_ops(&sdhi_sysc_dmac_dma_ops);
 
 	return 0;
 }
diff --git a/drivers/mmc/host/sh_mobile_sdhi.c b/drivers/mmc/host/sh_mobile_sdhi.c
index 45543ed37e5f..320059c61c6c 100644
--- a/drivers/mmc/host/sh_mobile_sdhi.c
+++ b/drivers/mmc/host/sh_mobile_sdhi.c
@@ -107,9 +107,9 @@ struct sh_mobile_sdhi {
 };
 
 #if IS_ENABLED(MMC_SDHI_SYSC_DMA)
-int tmio_mmc_init_dma(void);
+int sdhi_sysc_dmac_init_dma(void);
 #else
-static int tmio_mmc_init_dma(void)
+static int sdhi_sysc_dmac_init_dma(void)
 {
        return -EINVAL;
 }
@@ -372,7 +372,7 @@ static int sh_mobile_sdhi_probe(struct platform_device *pdev)
 		host->bus_shift = of_data->bus_shift;
 	}
 
-	ret = tmio_mmc_init_dma();
+	ret = sdhi_sysc_dmac_init_dma();
 	if (ret < 0)
 		goto efree;
 
-- 
2.7.0.rc3.207.g0ac5344

[PATCH/RFC v2 3/5] mmc: tmio: add max_segs and max_blk_count in tmio_mmc_data

[Simon Horman]

From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>

To change each value from related driver (e.g. sh_mobile_sdhi driver),
this patch adds these member in the struct tmio_mmc_data.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Ai Kyuse <ai.kyuse.uw@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
---
v2
* First post
---
 drivers/mmc/host/tmio_mmc_pio.c | 2 +-
 include/linux/mfd/tmio.h        | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/tmio_mmc_pio.c b/drivers/mmc/host/tmio_mmc_pio.c
index c0020c331595..39dd8402e126 100644
--- a/drivers/mmc/host/tmio_mmc_pio.c
+++ b/drivers/mmc/host/tmio_mmc_pio.c
@@ -1124,7 +1124,7 @@ int tmio_mmc_host_probe(struct tmio_mmc_host *_host,
 
 	mmc->caps |= MMC_CAP_4_BIT_DATA | pdata->capabilities;
 	mmc->caps2 |= pdata->capabilities2;
-	mmc->max_segs = 32;
+	mmc->max_segs = pdata->max_segs ? pdata->max_segs : 32;
 	mmc->max_blk_size = 512;
 	mmc->max_blk_count = (PAGE_SIZE / mmc->max_blk_size) *
 		mmc->max_segs;
diff --git a/include/linux/mfd/tmio.h b/include/linux/mfd/tmio.h
index 7a26286db895..3b95dc7eb314 100644
--- a/include/linux/mfd/tmio.h
+++ b/include/linux/mfd/tmio.h
@@ -125,6 +125,8 @@ struct tmio_mmc_data {
 	unsigned int			cd_gpio;
 	int				alignment_shift;
 	dma_addr_t			dma_rx_offset;
+	unsigned int			max_blk_count;
+	unsigned short			max_segs;
 	void (*set_pwr)(struct platform_device *host, int state);
 	void (*set_clk_div)(struct platform_device *host, int state);
 };
-- 
2.7.0.rc3.207.g0ac5344

[PATCH/RFC v2 4/5] mmc: sh_mobile_sdhi: add some SoC specific data for R-Car Gen3

[Simon Horman]

From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>

To avoid complicate code in own dma code for gen3, this patch
adds set max_segs to 1. Then, the tmio driver will get requests
as sg_len = 1 only.

In the performance point of view, the CONFIG_MMC_BLOCK_BOUNCE should
be set. Otherwise, mmc block layer will set 4-kbyte each as a request.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Ai Kyuse <ai.kyuse.uw@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
---
v2
* First post
---
 drivers/mmc/host/sh_mobile_sdhi.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/mmc/host/sh_mobile_sdhi.c b/drivers/mmc/host/sh_mobile_sdhi.c
index 320059c61c6c..51b5327557fa 100644
--- a/drivers/mmc/host/sh_mobile_sdhi.c
+++ b/drivers/mmc/host/sh_mobile_sdhi.c
@@ -54,6 +54,8 @@ struct sh_mobile_sdhi_of_data {
 	enum dma_slave_buswidth dma_buswidth;
 	dma_addr_t dma_rx_offset;
 	unsigned bus_shift;
+	unsigned int max_blk_count;
+	unsigned short max_segs;
 };
 
 static const struct sh_mobile_sdhi_of_data of_default_cfg = {
@@ -79,6 +81,9 @@ static const struct sh_mobile_sdhi_of_data of_rcar_gen3_compatible = {
 			  TMIO_MMC_CLK_ACTUAL | TMIO_MMC_MIN_RCAR2,
 	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ,
 	.bus_shift	= 2,
+	/* Gen3 SDHI DMAC can handle 0xffffffff blk count, but seg = 1 */
+	.max_blk_count  = 0xffffffff,
+	.max_segs = 1,
 };
 
 static const struct of_device_id sh_mobile_sdhi_of_match[] = {
@@ -368,6 +373,8 @@ static int sh_mobile_sdhi_probe(struct platform_device *pdev)
 		mmc_data->capabilities |= of_data->capabilities;
 		mmc_data->capabilities2 |= of_data->capabilities2;
 		mmc_data->dma_rx_offset = of_data->dma_rx_offset;
+		mmc_data->max_blk_count = of_data->max_blk_count;
+		mmc_data->max_segs = of_data->max_segs;
 		dma_priv->dma_buswidth = of_data->dma_buswidth;
 		host->bus_shift = of_data->bus_shift;
 	}
-- 
2.7.0.rc3.207.g0ac5344

[PATCH/RFC v2 5/5] mmc: renesas_sdhi: add support for R-Car Gen3 SDHI DMAC

[Simon Horman]

From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>

R-Car Gen3 has a dedicated DMA controller for SDHI module. Since
the DMAC is in a part of SDHI module and is not suitable as dmaengine,
this patch adds a different code as tmio_mmc_dma_gen3.c.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Ai Kyuse <ai.kyuse.uw@renesas.com>
---
v2 [Simon Horman]
* Correct build error in Mekefile
* Correct inverted logic in sh_mobile_sdhi_init_dma()
* Use renesas_sdhi_internal_dmac.c as new file name to better reflect
  the contents.

v1 [Simon Horman]
* Use newly introduced tmio_set_dma_ops() to allow driver
  to be compiled along side non-Gen3 SDHI DMA driver
  - - Use renesas_sdhi_dma_gen3.c rather than tmio_mmc_dma_gen3.c
      as source file name as driver is now attached to renesas_sdhi
      rather than tmio_core driver.
* Remove debugging code

v0 [Yoshihiro Shimoda]
---
 drivers/mmc/host/Kconfig                      |   9 ++
 drivers/mmc/host/Makefile                     |   3 +
 drivers/mmc/host/renesas_sdhi_internal_dmac.c | 192 ++++++++++++++++++++++++++
 drivers/mmc/host/sh_mobile_sdhi.c             |  31 ++++-
 4 files changed, 234 insertions(+), 1 deletion(-)
 create mode 100644 drivers/mmc/host/renesas_sdhi_internal_dmac.c

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index a0b6c1773e33..72471498b2b8 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -555,6 +555,7 @@ config MMC_SDHI
 	depends on SUPERH || ARCH_RENESAS || COMPILE_TEST
 	select MMC_TMIO_CORE
 	select MMC_SDHI_SYSC_DMA if (SUPERH || ARM)
+	select MMC_SDHI_INTERNAL_DMA if ARM64
 	help
 	  This provides support for the SDHI SD/SDIO controller found in
 	  SuperH and ARM SH-Mobile SoCs
@@ -567,6 +568,14 @@ config MMC_SDHI_SYSC_DMA
 	  This provides DMA support for the SDHI SD/SDIO controller
 	  found in SuperH and Renesas ARM based SoCs.
 
+config MMC_SDHI_INTERNAL_DMA
+	tristate "DMA support for Internal DMAC with SDHI SD/SDIO controller"
+	depends on ARM64
+	depends on MMC_SDHI
+	help
+	  This provides DMA support for the SDHI SD/SDIO controller
+	  found in Renesas arm64 based SoCs.
+
 config MMC_CB710
 	tristate "ENE CB710 MMC/SD Interface support"
 	depends on PCI
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index da5377e3ee4e..9c7e73b0c7d5 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -41,6 +41,9 @@ obj-$(CONFIG_MMC_SDHI)		+= sh_mobile_sdhi.o
 ifeq ($(subst m,y,$(CONFIG_MMC_SDHI_SYSC_DMA)),y)
 obj-$(CONFIG_MMC_SDHI)		+= renesas_sdhi_sysc_dmac.o
 endif
+ifeq ($(subst m,y,$(CONFIG_MMC_SDHI_INTERNAL_DMA)),y)
+obj-$(CONFIG_MMC_SDHI)		+= renesas_sdhi_internal_dmac.o
+endif
 obj-$(CONFIG_MMC_CB710)		+= cb710-mmc.o
 obj-$(CONFIG_MMC_VIA_SDMMC)	+= via-sdmmc.o
 obj-$(CONFIG_SDH_BFIN)		+= bfin_sdh.o
diff --git a/drivers/mmc/host/renesas_sdhi_internal_dmac.c b/drivers/mmc/host/renesas_sdhi_internal_dmac.c
new file mode 100644
index 000000000000..7f50cfa27d06
--- /dev/null
+++ b/drivers/mmc/host/renesas_sdhi_internal_dmac.c
@@ -0,0 +1,192 @@
+/*
+ * linux/drivers/mmc/renesas_sdhi_internal_dmac.c
+ *
+ * Copyright (C) 2015 Renesas Electronics Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * R-Car Gen3 DMA function for TMIO MMC implementations
+ */
+
+#include <linux/bug.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/mfd/tmio.h>
+#include <linux/mmc/host.h>
+#include <linux/pagemap.h>
+#include <linux/scatterlist.h>
+
+#include "tmio_mmc.h"
+
+#define DM_CM_DTRAN_MODE	0x820
+#define DM_CM_DTRAN_CTRL	0x828
+#define DM_CM_RST		0x830
+#define DM_CM_INFO1		0x840
+#define DM_CM_INFO1_MASK	0x848
+#define DM_CM_INFO2		0x850
+#define DM_CM_INFO2_MASK	0x858
+#define DM_DTRAN_ADDR		0x880
+
+/* DM_CM_DTRAN_MODE */
+#define DTRAN_MODE_CH_NUM_CH0	0	/* "downstream" = for write commands */
+#define DTRAN_MODE_CH_NUM_CH1	BIT(16)	/* "uptream" = for read commands */
+#define DTRAN_MODE_BUS_WID_TH	(BIT(5) | BIT(4))
+#define DTRAN_MODE_ADDR_MODE	BIT(0)	/* 1 = Increment address */
+
+/* DM_CM_DTRAN_CTRL */
+#define DTRAN_CTRL_DM_START	BIT(0)
+
+/* DM_CM_RST */
+#define RST_DTRANRST1		BIT(9)
+#define RST_DTRANRST0		BIT(8)
+#define RST_RESERVED_BITS	GENMASK_ULL(32, 0)
+
+/* DM_CM_INFO1 and DM_CM_INFO1_MASK */
+#define INFO1_DTRANEND1		BIT(17)
+#define INFO1_DTRANEND0		BIT(16)
+
+/* DM_CM_INFO2 and DM_CM_INFO2_MASK */
+#define INFO2_DTRANERR1		BIT(17)
+#define INFO2_DTRANERR0		BIT(16)
+
+/*
+ * Specification of this driver:
+ * - host->chan_{rx,tx} will be used as a flag of enabling/disabling the dma
+ * - Since this SDHI DMAC register set has actual 32-bit and "bus_shift" is 2,
+ *   this driver cannot use original sd_ctrl_{write,read}32 functions.
+ */
+
+static void tmio_dm_write(struct tmio_mmc_host *host, int addr, u64 val)
+{
+	writeq(val, host->ctl + addr);
+}
+
+static void sdhi_internal_dmac_enable_dma(struct tmio_mmc_host *host,
+					  bool enable)
+{
+	if (!host->chan_tx || !host->chan_rx)
+		return;
+
+	if (host->dma->enable)
+		host->dma->enable(host, enable);
+}
+
+static void sdhi_internal_dmac_abort_dma(struct tmio_mmc_host *host)
+{
+	u64 val = RST_DTRANRST1 | RST_DTRANRST0;
+
+	sdhi_internal_dmac_enable_dma(host, false);
+
+	tmio_dm_write(host, DM_CM_RST, RST_RESERVED_BITS & ~val);
+	tmio_dm_write(host, DM_CM_RST, RST_RESERVED_BITS | val);
+
+	sdhi_internal_dmac_enable_dma(host, true);
+}
+
+static void sdhi_internal_dmac_start_dma(struct tmio_mmc_host *host,
+			       struct mmc_data *data)
+{
+	struct scatterlist *sg = host->sg_ptr;
+	u32 dtran_mode = DTRAN_MODE_BUS_WID_TH | DTRAN_MODE_ADDR_MODE;
+	enum dma_data_direction dir;
+	int ret;
+	u32 irq_mask;
+
+	/* This DMAC cannot handle if sg_len is not 1 */
+	WARN_ON(host->sg_len > 1);
+
+	/* This DMAC cannot handle if buffer is not 8-bytes alignment */
+	if (!IS_ALIGNED(sg->offset, 8)) {
+		host->force_pio = true;
+		return;
+	}
+
+	if (data->flags & MMC_DATA_READ) {
+		dtran_mode |= DTRAN_MODE_CH_NUM_CH1;
+		dir = DMA_FROM_DEVICE;
+		irq_mask = TMIO_STAT_RXRDY;
+	} else {
+		dtran_mode |= DTRAN_MODE_CH_NUM_CH0;
+		dir = DMA_TO_DEVICE;
+		irq_mask = TMIO_STAT_TXRQ;
+	}
+
+	ret = dma_map_sg(&host->pdev->dev, sg, host->sg_len, dir);
+	if (ret < 0) {
+		dev_err(&host->pdev->dev, "%s: dma_map_sg failed\n", __func__);
+		return;
+	}
+
+	sdhi_internal_dmac_enable_dma(host, true);
+
+	/* disable PIO irqs to avoid "PIO IRQ in DMA mode!" */
+	tmio_mmc_disable_mmc_irqs(host, irq_mask);
+
+	/* set dma parameters */
+	tmio_dm_write(host, DM_CM_DTRAN_MODE, dtran_mode);
+	tmio_dm_write(host, DM_DTRAN_ADDR, sg->dma_address);
+}
+
+static void sdhi_internal_dmac_issue_tasklet_fn(unsigned long arg)
+{
+	struct tmio_mmc_host *host = (struct tmio_mmc_host *)arg;
+
+	tmio_mmc_enable_mmc_irqs(host, TMIO_STAT_DATAEND);
+
+	/* start the DMAC */
+	tmio_dm_write(host, DM_CM_DTRAN_CTRL, DTRAN_CTRL_DM_START);
+}
+
+static void sdhi_internal_dmac_complete_tasklet_fn(unsigned long arg)
+{
+	struct tmio_mmc_host *host = (struct tmio_mmc_host *)arg;
+	enum dma_data_direction dir;
+
+	if (!host->data)
+		return;
+
+	if (host->data->flags & MMC_DATA_READ)
+		dir = DMA_FROM_DEVICE;
+	else
+		dir = DMA_TO_DEVICE;
+
+	dma_unmap_sg(&host->pdev->dev, host->sg_ptr, host->sg_len, dir);
+	tmio_mmc_do_data_irq(host);
+}
+
+static void sdhi_internal_dmac_request_dma(struct tmio_mmc_host *host,
+					   struct tmio_mmc_data *pdata)
+{
+	/* Each value is set to non-zero to assume "enabling" each DMA */
+	host->chan_rx = host->chan_tx = (void *)0xdeadbeaf;
+
+	tasklet_init(&host->dma_complete,
+		     sdhi_internal_dmac_complete_tasklet_fn,
+		     (unsigned long)host);
+	tasklet_init(&host->dma_issue, sdhi_internal_dmac_issue_tasklet_fn,
+		     (unsigned long)host);
+}
+
+static void sdhi_internal_dmac_release_dma(struct tmio_mmc_host *host)
+{
+	/* Each value is set to zero to assume "disabling" each DMA */
+	host->chan_rx = host->chan_tx = NULL;
+}
+
+static struct tmio_mmc_dma_ops sdhi_internal_dmac_dma_ops = {
+	.start = sdhi_internal_dmac_start_dma,
+	.enable = sdhi_internal_dmac_enable_dma,
+	.request = sdhi_internal_dmac_request_dma,
+	.release = sdhi_internal_dmac_release_dma,
+	.abort = sdhi_internal_dmac_abort_dma,
+};
+
+int sdhi_internal_dmac_init_dma(void)
+{
+	tmio_set_dma_ops(&sdhi_internal_dmac_dma_ops);
+
+	return 0;
+}
diff --git a/drivers/mmc/host/sh_mobile_sdhi.c b/drivers/mmc/host/sh_mobile_sdhi.c
index 51b5327557fa..9359ff3a774a 100644
--- a/drivers/mmc/host/sh_mobile_sdhi.c
+++ b/drivers/mmc/host/sh_mobile_sdhi.c
@@ -47,6 +47,11 @@
 
 #define host_to_priv(host) container_of((host)->pdata, struct sh_mobile_sdhi, mmc_data)
 
+enum tmio_mmc_dmac_type {
+	TMIO_MMC_SYSC_DMAC	= 0,
+	TMIO_MMC_INTERNAL_DMAC,
+};
+
 struct sh_mobile_sdhi_of_data {
 	unsigned long tmio_flags;
 	unsigned long capabilities;
@@ -56,6 +61,7 @@ struct sh_mobile_sdhi_of_data {
 	unsigned bus_shift;
 	unsigned int max_blk_count;
 	unsigned short max_segs;
+	enum tmio_mmc_dmac_type dmac_type;
 };
 
 static const struct sh_mobile_sdhi_of_data of_default_cfg = {
@@ -84,6 +90,7 @@ static const struct sh_mobile_sdhi_of_data of_rcar_gen3_compatible = {
 	/* Gen3 SDHI DMAC can handle 0xffffffff blk count, but seg = 1 */
 	.max_blk_count  = 0xffffffff,
 	.max_segs = 1,
+	.dmac_type	= TMIO_MMC_INTERNAL_DMAC,
 };
 
 static const struct of_device_id sh_mobile_sdhi_of_match[] = {
@@ -120,6 +127,26 @@ static int sdhi_sysc_dmac_init_dma(void)
 }
 #endif
 
+#if IS_ENABLED(CONFIG_MMC_SDHI_INTERNAL_DMA)
+int sdhi_internal_dmac_init_dma(void);
+#else
+static int sdhi_internal_dmac_init_dma(void)
+{
+	return -EINVAL;
+}
+#endif
+
+static int sh_mobile_sdhi_init_dma(enum tmio_mmc_dmac_type dmac_type)
+{
+	switch (dmac_type) {
+	case TMIO_MMC_INTERNAL_DMAC:
+		return sdhi_internal_dmac_init_dma();
+
+	case TMIO_MMC_SYSC_DMAC:
+		return sdhi_sysc_dmac_init_dma();
+	}
+}
+
 static void sh_mobile_sdhi_sdbuf_width(struct tmio_mmc_host *host, int width)
 {
 	u32 val;
@@ -326,6 +353,7 @@ static int sh_mobile_sdhi_probe(struct platform_device *pdev)
 {
 	const struct of_device_id *of_id =
 		of_match_device(sh_mobile_sdhi_of_match, &pdev->dev);
+	enum tmio_mmc_dmac_type dmac_type = TMIO_MMC_SYSC_DMAC;
 	struct sh_mobile_sdhi *priv;
 	struct tmio_mmc_data *mmc_data;
 	struct tmio_mmc_data *mmd = pdev->dev.platform_data;
@@ -377,9 +405,10 @@ static int sh_mobile_sdhi_probe(struct platform_device *pdev)
 		mmc_data->max_segs = of_data->max_segs;
 		dma_priv->dma_buswidth = of_data->dma_buswidth;
 		host->bus_shift = of_data->bus_shift;
+		dmac_type = of_data->dmac_type;
 	}
 
-	ret = sdhi_sysc_dmac_init_dma();
+	ret = sh_mobile_sdhi_init_dma(dmac_type);
 	if (ret < 0)
 		goto efree;
 
-- 
2.7.0.rc3.207.g0ac5344

Re: [PATCH/RFC v2 5/5] mmc: renesas_sdhi: add support for R-Car Gen3 SDHI DMAC

[Arnd Bergmann]

On Thursday, June 30, 2016 12:05:40 AM CEST Simon Horman wrote:
> @@ -120,6 +127,26 @@ static int sdhi_sysc_dmac_init_dma(void)
>  }
>  #endif
>  
> +#if IS_ENABLED(CONFIG_MMC_SDHI_INTERNAL_DMA)
> +int sdhi_internal_dmac_init_dma(void);
> +#else
> +static int sdhi_internal_dmac_init_dma(void)
> +{
> +       return -EINVAL;
> +}
> +#endif
> +
> +static int sh_mobile_sdhi_init_dma(enum tmio_mmc_dmac_type dmac_type)
> +{
> +       switch (dmac_type) {
> +       case TMIO_MMC_INTERNAL_DMAC:
> +               return sdhi_internal_dmac_init_dma();
> +
> +       case TMIO_MMC_SYSC_DMAC:
> +               return sdhi_sysc_dmac_init_dma();
> +       }
> +}
> +

I think it would be nicer to turn the logic around and handle the
different kinds of TMIO hardware like we do it for the sdhci types:

Make the common portion of the driver a module that just exports
functions but doesn't register a driver, and then put each variant
(PIO, internal DMA, SYSC-DMA) into a separate module that registers
its own driver.

Do you think that makes sense in this case?

	Arnd

Re: [PATCH/RFC v2 5/5] mmc: renesas_sdhi: add support for R-Car Gen3 SDHI DMAC

[Geert Uytterhoeven]

On Thu, Jun 30, 2016 at 12:05 AM, Simon Horman
<horms+renesas@verge.net.au> wrote:
> --- a/drivers/mmc/host/sh_mobile_sdhi.c
> +++ b/drivers/mmc/host/sh_mobile_sdhi.c

> +static int sh_mobile_sdhi_init_dma(enum tmio_mmc_dmac_type dmac_type)
> +{
> +       switch (dmac_type) {
> +       case TMIO_MMC_INTERNAL_DMAC:
> +               return sdhi_internal_dmac_init_dma();
> +
> +       case TMIO_MMC_SYSC_DMAC:
> +               return sdhi_sysc_dmac_init_dma();
> +       }
> +}

Depending on compiler version and optimization level:

drivers/mmc/host/sh_mobile_sdhi.c:172:1: warning: control reaches end
of non-void function [-Wreturn-type]

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH/RFC v2 1/5] mmc: sh_mobile_sdhi, tmio: make dma more modular

[Geert Uytterhoeven]

Hi Simon,

On Thu, Jun 30, 2016 at 12:05 AM, Simon Horman
<horms+renesas@verge.net.au> wrote:
> Refactor DMA support to allow it to be provided by a set of call-backs
> that are provided by a host driver. The motivation is to allow multiple
> DMA implementations to be provided and instantiated at run-time.
>
> Instantiate the existing DMA implementation from the sh_mobile_sdhi driver
> which appears to match the current use-case. This has the side effect
> of moving the DMA code from the tmio_core to the sh_mobile_sdhi driver.
>
> A follow-up patch will change the source file for the SDHI DMA
> implementation accordingly.
>
> Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
> ---
> v2
> * Fix compilation issue due to error in Makefile
> * Use MMC_SDHI_SYSC_DMA rather than MMC_SDHI_DMA as new Kconfig symbole
>   to better reflect revamped file rename in a follow-up patch.
>
> Todo: Investigate removing ifdef
> ---
>  drivers/mmc/host/Kconfig          |  9 ++++++++
>  drivers/mmc/host/Makefile         |  4 +++-
>  drivers/mmc/host/sh_mobile_sdhi.c | 13 +++++++++++
>  drivers/mmc/host/tmio_mmc.h       | 39 ++++++++------------------------
>  drivers/mmc/host/tmio_mmc_dma.c   | 26 +++++++++++++++++-----
>  drivers/mmc/host/tmio_mmc_pio.c   | 47 +++++++++++++++++++++++++++++++++++++++
>  6 files changed, 102 insertions(+), 36 deletions(-)
>
> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> index 5274f503a39a..a0b6c1773e33 100644
> --- a/drivers/mmc/host/Kconfig
> +++ b/drivers/mmc/host/Kconfig
> @@ -554,10 +554,19 @@ config MMC_SDHI
>         depends on SUPERH || ARM || ARM64
>         depends on SUPERH || ARCH_RENESAS || COMPILE_TEST
>         select MMC_TMIO_CORE
> +       select MMC_SDHI_SYSC_DMA if (SUPERH || ARM)

MMC_SDHI_SYS_DMAC?

>         help
>           This provides support for the SDHI SD/SDIO controller found in
>           SuperH and ARM SH-Mobile SoCs
>
> +config MMC_SDHI_SYSC_DMA

MMC_SDHI_SYS_DMAC??

> +       tristate "DMA support use of SYSC DMAC with SDHI SD/SDIO controller"

SYS DMAC

(SYSC is the System Controller for Power Areas)

> +       depends on SUPERH || ARM || COMPILE_TEST
> +       depends on MMC_SDHI
> +       help
> +         This provides DMA support for the SDHI SD/SDIO controller
> +         found in SuperH and Renesas ARM based SoCs.
> +
>  config MMC_CB710
>         tristate "ENE CB710 MMC/SD Interface support"
>         depends on PCI
> diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
> index e2bdaaf43184..4ed6f250213a 100644
> --- a/drivers/mmc/host/Makefile
> +++ b/drivers/mmc/host/Makefile
> @@ -37,8 +37,10 @@ obj-$(CONFIG_MMC_SDRICOH_CS) += sdricoh_cs.o
>  obj-$(CONFIG_MMC_TMIO)         += tmio_mmc.o
>  obj-$(CONFIG_MMC_TMIO_CORE)    += tmio_mmc_core.o
>  tmio_mmc_core-y                        := tmio_mmc_pio.o
> -tmio_mmc_core-$(subst m,y,$(CONFIG_MMC_SDHI))  += tmio_mmc_dma.o
>  obj-$(CONFIG_MMC_SDHI)         += sh_mobile_sdhi.o
> +ifeq ($(subst m,y,$(CONFIG_MMC_SDHI_SYSC_DMA)),y)
> +obj-$(CONFIG_MMC_SDHI)         += tmio_mmc_dma.o
> +endif
>  obj-$(CONFIG_MMC_CB710)                += cb710-mmc.o
>  obj-$(CONFIG_MMC_VIA_SDMMC)    += via-sdmmc.o
>  obj-$(CONFIG_SDH_BFIN)         += bfin_sdh.o
> diff --git a/drivers/mmc/host/sh_mobile_sdhi.c b/drivers/mmc/host/sh_mobile_sdhi.c
> index c3b651bf89cb..45543ed37e5f 100644
> --- a/drivers/mmc/host/sh_mobile_sdhi.c
> +++ b/drivers/mmc/host/sh_mobile_sdhi.c
> @@ -106,6 +106,15 @@ struct sh_mobile_sdhi {
>         struct pinctrl_state *pins_default, *pins_uhs;
>  };
>
> +#if IS_ENABLED(MMC_SDHI_SYSC_DMA)

This should be "#if IS_ENABLED(CONFIG_MMC_SDHI_SYSC_DMA)",
else probing fails on all platforms where SDHI uses the SYS DMAC:

    sh_mobile_sdhi: probe of ee100000.sd failed with error -22

> +int tmio_mmc_init_dma(void);
> +#else
> +static int tmio_mmc_init_dma(void)
> +{
> +       return -EINVAL;

Still, I don't know if this is the right approach: if CONFIG_MMC_SDHI_SYSC_DMA
is ever disabled, the driver will just fail during probing, instead of falling
back to PIO.

> +}
> +#endif
> +

And there's another issue:

    WARNING: modpost: Found 1 section mismatch(es).
    To see full details build your kernel with:
    'make CONFIG_DEBUG_SECTION_MISMATCH=y'

Doing that doesn't help much, though:

    WARNING: drivers/built-in.o(.text+0x190f7c): Section mismatch in
reference from
    the function tmio_mmc_init_dma() to the (unknown reference)
    .init.data:(unknown)
    The function tmio_mmc_init_dma() references
    the (unknown reference) __initdata (unknown).
    This is often because tmio_mmc_init_dma lacks a __initdata
    annotation or the annotation of (unknown) is wrong.

The warning goes away later in the series, though.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH/RFC v2 1/5] mmc: sh_mobile_sdhi, tmio: make dma more modular

[Simon Horman]

On Tue, Jul 05, 2016 at 07:05:55PM +0200, Geert Uytterhoeven wrote:
> Hi Simon,
> 
> On Thu, Jun 30, 2016 at 12:05 AM, Simon Horman
> <horms+renesas@verge.net.au> wrote:
> > Refactor DMA support to allow it to be provided by a set of call-backs
> > that are provided by a host driver. The motivation is to allow multiple
> > DMA implementations to be provided and instantiated at run-time.
> >
> > Instantiate the existing DMA implementation from the sh_mobile_sdhi driver
> > which appears to match the current use-case. This has the side effect
> > of moving the DMA code from the tmio_core to the sh_mobile_sdhi driver.
> >
> > A follow-up patch will change the source file for the SDHI DMA
> > implementation accordingly.
> >
> > Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
> > ---
> > v2
> > * Fix compilation issue due to error in Makefile
> > * Use MMC_SDHI_SYSC_DMA rather than MMC_SDHI_DMA as new Kconfig symbole
> >   to better reflect revamped file rename in a follow-up patch.
> >
> > Todo: Investigate removing ifdef
> > ---
> >  drivers/mmc/host/Kconfig          |  9 ++++++++
> >  drivers/mmc/host/Makefile         |  4 +++-
> >  drivers/mmc/host/sh_mobile_sdhi.c | 13 +++++++++++
> >  drivers/mmc/host/tmio_mmc.h       | 39 ++++++++------------------------
> >  drivers/mmc/host/tmio_mmc_dma.c   | 26 +++++++++++++++++-----
> >  drivers/mmc/host/tmio_mmc_pio.c   | 47 +++++++++++++++++++++++++++++++++++++++
> >  6 files changed, 102 insertions(+), 36 deletions(-)
> >
> > diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> > index 5274f503a39a..a0b6c1773e33 100644
> > --- a/drivers/mmc/host/Kconfig
> > +++ b/drivers/mmc/host/Kconfig
> > @@ -554,10 +554,19 @@ config MMC_SDHI
> >         depends on SUPERH || ARM || ARM64
> >         depends on SUPERH || ARCH_RENESAS || COMPILE_TEST
> >         select MMC_TMIO_CORE
> > +       select MMC_SDHI_SYSC_DMA if (SUPERH || ARM)
> 
> MMC_SDHI_SYS_DMAC?
> 
> >         help
> >           This provides support for the SDHI SD/SDIO controller found in
> >           SuperH and ARM SH-Mobile SoCs
> >
> > +config MMC_SDHI_SYSC_DMA
> 
> MMC_SDHI_SYS_DMAC??
> 
> > +       tristate "DMA support use of SYSC DMAC with SDHI SD/SDIO controller"
> 
> SYS DMAC
> 
> (SYSC is the System Controller for Power Areas)

Thanks, I will use SYS DMAC (everywhere).

> > +       depends on SUPERH || ARM || COMPILE_TEST
> > +       depends on MMC_SDHI
> > +       help
> > +         This provides DMA support for the SDHI SD/SDIO controller
> > +         found in SuperH and Renesas ARM based SoCs.
> > +
> >  config MMC_CB710
> >         tristate "ENE CB710 MMC/SD Interface support"
> >         depends on PCI
> > diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
> > index e2bdaaf43184..4ed6f250213a 100644
> > --- a/drivers/mmc/host/Makefile
> > +++ b/drivers/mmc/host/Makefile
> > @@ -37,8 +37,10 @@ obj-$(CONFIG_MMC_SDRICOH_CS) += sdricoh_cs.o
> >  obj-$(CONFIG_MMC_TMIO)         += tmio_mmc.o
> >  obj-$(CONFIG_MMC_TMIO_CORE)    += tmio_mmc_core.o
> >  tmio_mmc_core-y                        := tmio_mmc_pio.o
> > -tmio_mmc_core-$(subst m,y,$(CONFIG_MMC_SDHI))  += tmio_mmc_dma.o
> >  obj-$(CONFIG_MMC_SDHI)         += sh_mobile_sdhi.o
> > +ifeq ($(subst m,y,$(CONFIG_MMC_SDHI_SYSC_DMA)),y)
> > +obj-$(CONFIG_MMC_SDHI)         += tmio_mmc_dma.o
> > +endif
> >  obj-$(CONFIG_MMC_CB710)                += cb710-mmc.o
> >  obj-$(CONFIG_MMC_VIA_SDMMC)    += via-sdmmc.o
> >  obj-$(CONFIG_SDH_BFIN)         += bfin_sdh.o
> > diff --git a/drivers/mmc/host/sh_mobile_sdhi.c b/drivers/mmc/host/sh_mobile_sdhi.c
> > index c3b651bf89cb..45543ed37e5f 100644
> > --- a/drivers/mmc/host/sh_mobile_sdhi.c
> > +++ b/drivers/mmc/host/sh_mobile_sdhi.c
> > @@ -106,6 +106,15 @@ struct sh_mobile_sdhi {
> >         struct pinctrl_state *pins_default, *pins_uhs;
> >  };
> >
> > +#if IS_ENABLED(MMC_SDHI_SYSC_DMA)
> 
> This should be "#if IS_ENABLED(CONFIG_MMC_SDHI_SYSC_DMA)",
> else probing fails on all platforms where SDHI uses the SYS DMAC:
> 
>     sh_mobile_sdhi: probe of ee100000.sd failed with error -22

Ooops, I will fix that.

> > +int tmio_mmc_init_dma(void);
> > +#else
> > +static int tmio_mmc_init_dma(void)
> > +{
> > +       return -EINVAL;
> 
> Still, I don't know if this is the right approach: if CONFIG_MMC_SDHI_SYSC_DMA
> is ever disabled, the driver will just fail during probing, instead of falling
> back to PIO.

I will switch things around to allow fallback to PIO.

> 
> > +}
> > +#endif
> > +
> 
> And there's another issue:
> 
>     WARNING: modpost: Found 1 section mismatch(es).
>     To see full details build your kernel with:
>     'make CONFIG_DEBUG_SECTION_MISMATCH=y'
> 
> Doing that doesn't help much, though:
> 
>     WARNING: drivers/built-in.o(.text+0x190f7c): Section mismatch in
> reference from
>     the function tmio_mmc_init_dma() to the (unknown reference)
>     .init.data:(unknown)
>     The function tmio_mmc_init_dma() references
>     the (unknown reference) __initdata (unknown).
>     This is often because tmio_mmc_init_dma lacks a __initdata
>     annotation or the annotation of (unknown) is wrong.
> 
> The warning goes away later in the series, though.

I think this is due to the __initdata annotation of
tmio_mmc_dma_ops which is removed later in the series. I will remove it
here.

> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds
>