[PATCH/RFC 4/4] mmc: renesas_sdhi: add support for R-Car Gen3 SDHI DMAC

Simon Horman
2016-06-15T04:02:39Z

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>
---
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 | 1 +
drivers/mmc/host/renesas_sdhi.c | 32 +++++-
drivers/mmc/host/renesas_sdhi_dma_gen3.c | 190 +++++++++++++++++++++++++++++++
4 files changed, 231 insertions(+), 1 deletion(-)
create mode 100644 drivers/mmc/host/renesas_sdhi_dma_gen3.c

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 7ccae04632aa..5b9af094daba 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -565,6 +565,7 @@ config MMC_SDHI
depends on SUPERH || ARCH_RENESAS || COMPILE_TEST
select MMC_TMIO_CORE
select MMC_SDHI_DMA if (SUPERH || ARM)
+ select MMC_SDHI_DMA_GEN3 if ARM64
help
This provides support for the SDHI SD/SDIO controller found in
SuperH, and Renesas ARM and arm64 based SoCs.
@@ -577,6 +578,14 @@ config MMC_SDHI_DMA
This provides DMA support for the DMA support the SDHI SD/SDIO
found in SuperH and Renesas ARM based SoCs.

+config MMC_SDHI_DMA_GEN3
+ tristate "DMA support for R-Car Gen3 Renesas SDHI SD/SDIO controller"
+ depends on ARM64
+ depends on MMC_SDHI
+ help
+ This provides DMA support for the DMA support the SDHI SD/SDIO
+ found in Renesas ARM and 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 0ea7fb6f3d5e..5557203ce8b9 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -39,6 +39,7 @@ obj-$(CONFIG_MMC_TMIO_CORE) += tmio_mmc_core.o
tmio_mmc_core-y := tmio_mmc_pio.o
obj-$(CONFIG_MMC_SDHI) += renesas_sdhi.o
renesas_sdhi-$(subst m,y,$(CONFIG_MMC_SDHI_DMA)) += renesas_sdhi_dma.o
+renesas_sdhi-$(subst m,y,$(CONFIG_MMC_SDHI_DMA_GEN3)) += renesas_sdhi_dma_gen3.o
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.c b/drivers/mmc/host/renesas_sdhi.c
index 4403dfe1413d..74fe25bfe5c4 100644
--- a/drivers/mmc/host/renesas_sdhi.c
+++ b/drivers/mmc/host/renesas_sdhi.c
@@ -47,6 +47,11 @@

#define host_to_priv(host) container_of((host)->pdata, struct sh_mobile_sdhi, mmc_data)

+enum tmio_mmc_dma_type {
+ TMIO_MMC_DMA_TYPE_DEFAULT = 0,
+ TMIO_MMC_DMA_TYPE_GEN3,
+};
+
struct sh_mobile_sdhi_of_data {
unsigned long tmio_flags;
unsigned long capabilities;
@@ -54,6 +59,7 @@ struct sh_mobile_sdhi_of_data {
enum dma_slave_buswidth dma_buswidth;
dma_addr_t dma_rx_offset;
unsigned bus_shift;
+ enum tmio_mmc_dma_type dma_type;
};

static const struct sh_mobile_sdhi_of_data of_default_cfg = {
@@ -79,6 +85,7 @@ 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,
+ .dma_type = TMIO_MMC_DMA_TYPE_GEN3,
};

static const struct of_device_id sh_mobile_sdhi_of_match[] = {
@@ -115,6 +122,27 @@ static int tmio_mmc_init_dma(void)
}
#endif

+#if IS_ENABLED(CONFIG_MMC_SDHI_DMA_GEN3)
+int tmio_mmc_init_dma_gen3(void);
+#else
+static int tmio_mmc_init_dma_gen3(void)
+{
+ return -EINVAL;
+}
+#endif
+
+static int sh_mobile_sdhi_init_dma(enum tmio_mmc_dma_type dma_type)
+{
+ switch (dma_type) {
+ case TMIO_MMC_DMA_TYPE_DEFAULT:
+ return tmio_mmc_init_dma_gen3();
+
+ case TMIO_MMC_DMA_TYPE_GEN3:
+ default:
+ return tmio_mmc_init_dma();
+ }
+}
+
static void sh_mobile_sdhi_sdbuf_width(struct tmio_mmc_host *host, int width)
{
u32 val;
@@ -321,6 +349,7 @@ 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_dma_type dma_type = TMIO_MMC_DMA_TYPE_DEFAULT;
struct sh_mobile_sdhi *priv;
struct tmio_mmc_data *mmc_data;
struct tmio_mmc_data *mmd = pdev->dev.platform_data;
@@ -370,9 +399,10 @@ static int sh_mobile_sdhi_probe(struct platform_device *pdev)
mmc_data->dma_rx_offset = of_data->dma_rx_offset;
dma_priv->dma_buswidth = of_data->dma_buswidth;
host->bus_shift = of_data->bus_shift;
+ dma_type = of_data->dma_type;
}

- ret = tmio_mmc_init_dma();
+ ret = sh_mobile_sdhi_init_dma(dma_type);
if (ret < 0)
goto efree;

diff --git a/drivers/mmc/host/renesas_sdhi_dma_gen3.c b/drivers/mmc/host/renesas_sdhi_dma_gen3.c
new file mode 100644
index 000000000000..55d6a65e12b3
--- /dev/null
+++ b/drivers/mmc/host/renesas_sdhi_dma_gen3.c
@@ -0,0 +1,190 @@
+/*
+ * linux/drivers/mmc/tmio_mmc_dma_gen3.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 tmio_mmc_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 tmio_mmc_abort_dma(struct tmio_mmc_host *host)
+{
+ u64 val = RST_DTRANRST1 | RST_DTRANRST0;
+
+ tmio_mmc_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);
+
+ tmio_mmc_enable_dma(host, true);
+}
+
+static void tmio_mmc_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;
+ }
+
+ tmio_mmc_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 tmio_mmc_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 tmio_mmc_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 tmio_mmc_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, tmio_mmc_complete_tasklet_fn,
+ (unsigned long)host);
+ tasklet_init(&host->dma_issue, tmio_mmc_issue_tasklet_fn,
+ (unsigned long)host);
+}
+
+static void tmio_mmc_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 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_gen3(void)
+{
+ tmio_set_dma_ops(&tmio_mmc_dma_ops);
+
+ return 0;
+}
--
2.1.4