* [PATCH v2] ARM: dts: imx6dl: disable dma support for spi on i.mx6dl
@ 2014-10-21 1:06 Robin Gong
2014-10-21 1:06 ` [PATCH v1] ARM: imx6: add pm_power_off support for i.mx6 chips Robin Gong
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Robin Gong @ 2014-10-21 1:06 UTC (permalink / raw)
To: vinod.koul, dan.j.williams, andriy.shevchenko
Cc: dmaengine, linux-kernel, b38343
There is one weird data in rxfifo after one full rx/tx transfer
done sometimes. It looks a design issue and hard to workaround
totally, so disable dma functhion here. And will re-enable it
once the root cause found.
Signed-off-by: Robin Gong <b38343@freescale.com>
---
arch/arm/boot/dts/imx6q.dtsi | 20 ++++++++++++++++++++
arch/arm/boot/dts/imx6qdl.dtsi | 8 --------
2 files changed, 20 insertions(+), 8 deletions(-)
diff --git a/arch/arm/boot/dts/imx6q.dtsi b/arch/arm/boot/dts/imx6q.dtsi
index e9f3646..8d5d33b 100644
--- a/arch/arm/boot/dts/imx6q.dtsi
+++ b/arch/arm/boot/dts/imx6q.dtsi
@@ -291,6 +291,26 @@
};
};
+&ecspi1 {
+ dmas = <&sdma 3 7 1>, <&sdma 4 7 2>;
+ dma-names = "rx", "tx";
+};
+
+&ecspi2 {
+ dmas = <&sdma 5 7 1>, <&sdma 6 7 2>;
+ dma-names = "rx", "tx";
+};
+
+&ecspi3 {
+ dmas = <&sdma 7 7 1>, <&sdma 8 7 2>;
+ dma-names = "rx", "tx";
+};
+
+&ecspi4 {
+ dmas = <&sdma 9 7 1>, <&sdma 10 7 2>;
+ dma-names = "rx", "tx";
+};
+
&mipi_dsi {
port@2 {
reg = <2>;
diff --git a/arch/arm/boot/dts/imx6qdl.dtsi b/arch/arm/boot/dts/imx6qdl.dtsi
index 70d7207..f696546 100644
--- a/arch/arm/boot/dts/imx6qdl.dtsi
+++ b/arch/arm/boot/dts/imx6qdl.dtsi
@@ -210,8 +210,6 @@
clocks = <&clks IMX6QDL_CLK_ECSPI1>,
<&clks IMX6QDL_CLK_ECSPI1>;
clock-names = "ipg", "per";
- dmas = <&sdma 3 7 1>, <&sdma 4 7 2>;
- dma-names = "rx", "tx";
status = "disabled";
};
@@ -224,8 +222,6 @@
clocks = <&clks IMX6QDL_CLK_ECSPI2>,
<&clks IMX6QDL_CLK_ECSPI2>;
clock-names = "ipg", "per";
- dmas = <&sdma 5 7 1>, <&sdma 6 7 2>;
- dma-names = "rx", "tx";
status = "disabled";
};
@@ -238,8 +234,6 @@
clocks = <&clks IMX6QDL_CLK_ECSPI3>,
<&clks IMX6QDL_CLK_ECSPI3>;
clock-names = "ipg", "per";
- dmas = <&sdma 7 7 1>, <&sdma 8 7 2>;
- dma-names = "rx", "tx";
status = "disabled";
};
@@ -252,8 +246,6 @@
clocks = <&clks IMX6QDL_CLK_ECSPI4>,
<&clks IMX6QDL_CLK_ECSPI4>;
clock-names = "ipg", "per";
- dmas = <&sdma 9 7 1>, <&sdma 10 7 2>;
- dma-names = "rx", "tx";
status = "disabled";
};
--
1.9.1
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH v1] ARM: imx6: add pm_power_off support for i.mx6 chips 2014-10-21 1:06 [PATCH v2] ARM: dts: imx6dl: disable dma support for spi on i.mx6dl Robin Gong @ 2014-10-21 1:06 ` Robin Gong 2014-10-21 1:06 ` [PATCH v6] spi: spi-imx: add DMA support Robin Gong 2014-10-21 1:06 ` [PATCH v4 0/3] dma: imx-sdma: add support for sdma memory copy Robin Gong 2 siblings, 0 replies; 6+ messages in thread From: Robin Gong @ 2014-10-21 1:06 UTC (permalink / raw) To: vinod.koul, dan.j.williams, andriy.shevchenko Cc: dmaengine, linux-kernel, b38343 All chips of i.mx6 can be powered off by programming SNVS. For example : On i.mx6q-sabresd board, PMIC_ON_REQ connect with external pmic ON/OFF pin, that will cause the whole PMIC powered off except VSNVS. And system can restart once PMIC_ON_REQ goes high by push POWRER key. Signed-off-by: Robin Gong <b38343@freescale.com> --- arch/arm/mach-imx/common.h | 1 + arch/arm/mach-imx/mach-imx6q.c | 2 ++ arch/arm/mach-imx/mach-imx6sl.c | 2 ++ arch/arm/mach-imx/mach-imx6sx.c | 2 ++ arch/arm/mach-imx/system.c | 22 +++++++++++++++++++++- 5 files changed, 28 insertions(+), 1 deletion(-) diff --git a/arch/arm/mach-imx/common.h b/arch/arm/mach-imx/common.h index 1dabf43..baca11a 100644 --- a/arch/arm/mach-imx/common.h +++ b/arch/arm/mach-imx/common.h @@ -62,6 +62,7 @@ void mxc_set_cpu_type(unsigned int type); void mxc_restart(enum reboot_mode, const char *); void mxc_arch_reset_init(void __iomem *); void mxc_arch_reset_init_dt(void); +void mxc_power_off_init(void); int mx51_revision(void); int mx53_revision(void); void imx_set_aips(void __iomem *); diff --git a/arch/arm/mach-imx/mach-imx6q.c b/arch/arm/mach-imx/mach-imx6q.c index d51c6e9..3d6610d 100644 --- a/arch/arm/mach-imx/mach-imx6q.c +++ b/arch/arm/mach-imx/mach-imx6q.c @@ -270,6 +270,8 @@ static void __init imx6q_init_machine(void) mxc_arch_reset_init_dt(); + mxc_power_off_init(); + parent = imx_soc_device_init(); if (parent == NULL) pr_warn("failed to initialize soc device\n"); diff --git a/arch/arm/mach-imx/mach-imx6sl.c b/arch/arm/mach-imx/mach-imx6sl.c index ed263a2..c07e6e8 100644 --- a/arch/arm/mach-imx/mach-imx6sl.c +++ b/arch/arm/mach-imx/mach-imx6sl.c @@ -50,6 +50,8 @@ static void __init imx6sl_init_machine(void) mxc_arch_reset_init_dt(); + mxc_power_off_init(); + parent = imx_soc_device_init(); if (parent == NULL) pr_warn("failed to initialize soc device\n"); diff --git a/arch/arm/mach-imx/mach-imx6sx.c b/arch/arm/mach-imx/mach-imx6sx.c index 3de3b73..68ea070 100644 --- a/arch/arm/mach-imx/mach-imx6sx.c +++ b/arch/arm/mach-imx/mach-imx6sx.c @@ -20,6 +20,8 @@ static void __init imx6sx_init_machine(void) mxc_arch_reset_init_dt(); + mxc_power_off_init(); + parent = imx_soc_device_init(); if (parent == NULL) pr_warn("failed to initialize soc device\n"); diff --git a/arch/arm/mach-imx/system.c b/arch/arm/mach-imx/system.c index d14c33f..925fb29 100644 --- a/arch/arm/mach-imx/system.c +++ b/arch/arm/mach-imx/system.c @@ -23,6 +23,7 @@ #include <linux/delay.h> #include <linux/of.h> #include <linux/of_address.h> +#include <linux/pm.h> #include <asm/system_misc.h> #include <asm/proc-fns.h> @@ -32,7 +33,9 @@ #include "common.h" #include "hardware.h" -static void __iomem *wdog_base; +#define SNVS_LPCR 0x04 + +static void __iomem *wdog_base, *snvs_base; static struct clk *wdog_clk; /* @@ -104,6 +107,23 @@ void __init mxc_arch_reset_init_dt(void) clk_prepare(wdog_clk); } +static void power_off_snvs(void) +{ + u32 value = readl(snvs_base + SNVS_LPCR); + /* set TOP and DP_EN bit */ + writel(value | 0x60, snvs_base + SNVS_LPCR); +} + +void __init mxc_power_off_init(void) +{ + struct device_node *np; + + np = of_find_compatible_node(NULL, NULL, "fsl,sec-v4.0-mon-rtc-lp"); + snvs_base = of_iomap(np, 0); + WARN_ON(!snvs_base); + pm_power_off = power_off_snvs; +} + #ifdef CONFIG_CACHE_L2X0 void __init imx_init_l2cache(void) { -- 1.9.1 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v6] spi: spi-imx: add DMA support 2014-10-21 1:06 [PATCH v2] ARM: dts: imx6dl: disable dma support for spi on i.mx6dl Robin Gong 2014-10-21 1:06 ` [PATCH v1] ARM: imx6: add pm_power_off support for i.mx6 chips Robin Gong @ 2014-10-21 1:06 ` Robin Gong 2014-10-21 2:14 ` Yibin Gong 2014-10-21 1:06 ` [PATCH v4 0/3] dma: imx-sdma: add support for sdma memory copy Robin Gong 2 siblings, 1 reply; 6+ messages in thread From: Robin Gong @ 2014-10-21 1:06 UTC (permalink / raw) To: vinod.koul, dan.j.williams, andriy.shevchenko Cc: dmaengine, linux-kernel, b38343 Enable DMA support on i.mx6. The read speed can increase from 600KB/s to 1.2MB/s on i.mx6q. You can disable or enable dma function in dts. If not set "dma-names" in dts, spi will use PIO mode. This patch only validate on i.mx6, not i.mx5, but encourage ones to apply this patch on i.mx5 since they share the same IP. Note: Sometime, there is a weid data in rxfifo after one full tx/rx transfer finish by DMA on i.mx6dl, so we disable dma functhion on i.mx6dl. Signed-off-by: Frank Li <Frank.Li@freescale.com> Signed-off-by: Robin Gong <b38343@freescale.com> --- Change from v5: 1. Update binding doc fsl-imx-cspi.txt. 2. remove usedma flag set from can_dma interface. Change from v4: 1. Enrich comments. 2. Remove the rxfifo workaround. The issue only exist on i.mx6dl, so disable dma function in dts. Change from v3: 1. Use spi core framwork to handle dump tx/rx buf 2. Add one workaround for weird data in rxfifo when one full transfer done. Change from v2: http://thread.gmane.org/gmane.linux.ports.arm.kernel/291722/focus=294363 1. Dma setup only for imx51-ecspi 2. Use one small dummy buffer(1 bd size) to templiy store data for meanless rx/tx, instead of malloc the actual transfer size. 3. Split spi_mx_sdma_transfer to smaller and easily to read. 4. Fix some code indent. --- .../devicetree/bindings/spi/fsl-imx-cspi.txt | 5 + drivers/spi/spi-imx.c | 286 ++++++++++++++++++++- 2 files changed, 285 insertions(+), 6 deletions(-) diff --git a/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt b/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt index 4256a6d..aad527b 100644 --- a/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt +++ b/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt @@ -7,6 +7,9 @@ Required properties: - interrupts : Should contain CSPI/eCSPI interrupt - fsl,spi-num-chipselects : Contains the number of the chipselect - cs-gpios : Specifies the gpio pins to be used for chipselects. +- dmas: DMA specifiers for tx and rx dma. See the DMA client binding, + Documentation/devicetree/bindings/dma/dma.txt +- dma-names: DMA request names should include "tx" and "rx" if present. Example: @@ -19,4 +22,6 @@ ecspi@70010000 { fsl,spi-num-chipselects = <2>; cs-gpios = <&gpio3 24 0>, /* GPIO3_24 */ <&gpio3 25 0>; /* GPIO3_25 */ + dmas = <&sdma 3 7 1>, <&sdma 4 7 2>; + dma-names = "rx", "tx"; }; diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c index 5daff20..3637847 100644 --- a/drivers/spi/spi-imx.c +++ b/drivers/spi/spi-imx.c @@ -21,6 +21,8 @@ #include <linux/clk.h> #include <linux/completion.h> #include <linux/delay.h> +#include <linux/dmaengine.h> +#include <linux/dma-mapping.h> #include <linux/err.h> #include <linux/gpio.h> #include <linux/interrupt.h> @@ -37,6 +39,7 @@ #include <linux/of_device.h> #include <linux/of_gpio.h> +#include <linux/platform_data/dma-imx.h> #include <linux/platform_data/spi-imx.h> #define DRIVER_NAME "spi_imx" @@ -51,6 +54,9 @@ #define MXC_INT_RR (1 << 0) /* Receive data ready interrupt */ #define MXC_INT_TE (1 << 1) /* Transmit FIFO empty interrupt */ +/* The maximum bytes that a sdma BD can transfer.*/ +#define MAX_SDMA_BD_BYTES (1 << 15) +#define IMX_DMA_TIMEOUT (msecs_to_jiffies(3000)) struct spi_imx_config { unsigned int speed_hz; unsigned int bpw; @@ -95,6 +101,16 @@ struct spi_imx_data { const void *tx_buf; unsigned int txfifo; /* number of words pushed in tx FIFO */ + /* DMA */ + unsigned int dma_is_inited; + unsigned int dma_finished; + bool usedma; + u32 rx_wml; + u32 tx_wml; + u32 rxt_wml; + struct completion dma_rx_completion; + struct completion dma_tx_completion; + const struct spi_imx_devtype_data *devtype_data; int chipselect[0]; }; @@ -181,9 +197,21 @@ static unsigned int spi_imx_clkdiv_2(unsigned int fin, return 7; } +static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi, + struct spi_transfer *transfer) +{ + struct spi_imx_data *spi_imx = spi_master_get_devdata(master); + + if (spi_imx->dma_is_inited && (transfer->len > spi_imx->rx_wml) + && (transfer->len > spi_imx->tx_wml)) + return true; + return false; +} + #define MX51_ECSPI_CTRL 0x08 #define MX51_ECSPI_CTRL_ENABLE (1 << 0) #define MX51_ECSPI_CTRL_XCH (1 << 2) +#define MX51_ECSPI_CTRL_SMC (1 << 3) #define MX51_ECSPI_CTRL_MODE_MASK (0xf << 4) #define MX51_ECSPI_CTRL_POSTDIV_OFFSET 8 #define MX51_ECSPI_CTRL_PREDIV_OFFSET 12 @@ -201,6 +229,18 @@ static unsigned int spi_imx_clkdiv_2(unsigned int fin, #define MX51_ECSPI_INT_TEEN (1 << 0) #define MX51_ECSPI_INT_RREN (1 << 3) +#define MX51_ECSPI_DMA 0x14 +#define MX51_ECSPI_DMA_TX_WML_OFFSET 0 +#define MX51_ECSPI_DMA_TX_WML_MASK 0x3F +#define MX51_ECSPI_DMA_RX_WML_OFFSET 16 +#define MX51_ECSPI_DMA_RX_WML_MASK (0x3F << 16) +#define MX51_ECSPI_DMA_RXT_WML_OFFSET 24 +#define MX51_ECSPI_DMA_RXT_WML_MASK (0x3F << 24) + +#define MX51_ECSPI_DMA_TEDEN_OFFSET 7 +#define MX51_ECSPI_DMA_RXDEN_OFFSET 23 +#define MX51_ECSPI_DMA_RXTDEN_OFFSET 31 + #define MX51_ECSPI_STAT 0x18 #define MX51_ECSPI_STAT_RR (1 << 3) @@ -257,17 +297,22 @@ static void __maybe_unused mx51_ecspi_intctrl(struct spi_imx_data *spi_imx, int static void __maybe_unused mx51_ecspi_trigger(struct spi_imx_data *spi_imx) { - u32 reg; - - reg = readl(spi_imx->base + MX51_ECSPI_CTRL); - reg |= MX51_ECSPI_CTRL_XCH; + u32 reg = readl(spi_imx->base + MX51_ECSPI_CTRL); + + if (!spi_imx->usedma) + reg |= MX51_ECSPI_CTRL_XCH; + else if (!spi_imx->dma_finished) + reg |= MX51_ECSPI_CTRL_SMC; + else + reg &= ~MX51_ECSPI_CTRL_SMC; writel(reg, spi_imx->base + MX51_ECSPI_CTRL); } static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx, struct spi_imx_config *config) { - u32 ctrl = MX51_ECSPI_CTRL_ENABLE, cfg = 0; + u32 ctrl = MX51_ECSPI_CTRL_ENABLE, cfg = 0, dma = 0; + u32 tx_wml_cfg, rx_wml_cfg, rxt_wml_cfg; u32 clk = config->speed_hz, delay; /* @@ -319,6 +364,30 @@ static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx, else /* SCLK is _very_ slow */ usleep_range(delay, delay + 10); + /* + * Configure the DMA register: setup the watermark + * and enable DMA request. + */ + if (spi_imx->dma_is_inited) { + dma = readl(spi_imx->base + MX51_ECSPI_DMA); + + spi_imx->tx_wml = spi_imx_get_fifosize(spi_imx) / 2; + spi_imx->rx_wml = spi_imx_get_fifosize(spi_imx) / 2; + spi_imx->rxt_wml = spi_imx_get_fifosize(spi_imx) / 2; + rx_wml_cfg = spi_imx->rx_wml << MX51_ECSPI_DMA_RX_WML_OFFSET; + tx_wml_cfg = spi_imx->tx_wml << MX51_ECSPI_DMA_TX_WML_OFFSET; + rxt_wml_cfg = spi_imx->rxt_wml << MX51_ECSPI_DMA_RXT_WML_OFFSET; + dma = (dma & ~MX51_ECSPI_DMA_TX_WML_MASK + & ~MX51_ECSPI_DMA_RX_WML_MASK + & ~MX51_ECSPI_DMA_RXT_WML_MASK) + | rx_wml_cfg | tx_wml_cfg | rxt_wml_cfg + |(1 << MX51_ECSPI_DMA_TEDEN_OFFSET) + |(1 << MX51_ECSPI_DMA_RXDEN_OFFSET) + |(1 << MX51_ECSPI_DMA_RXTDEN_OFFSET); + + writel(dma, spi_imx->base + MX51_ECSPI_DMA); + } + return 0; } @@ -730,7 +799,186 @@ static int spi_imx_setupxfer(struct spi_device *spi, return 0; } -static int spi_imx_transfer(struct spi_device *spi, +static void spi_imx_sdma_exit(struct spi_imx_data *spi_imx) +{ + struct spi_master *master = spi_imx->bitbang.master; + + if (master->dma_rx) { + dma_release_channel(master->dma_rx); + master->dma_rx = NULL; + } + + if (master->dma_tx) { + dma_release_channel(master->dma_tx); + master->dma_tx = NULL; + } + + spi_imx->dma_is_inited = 0; +} + +static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx, + struct spi_master *master, + const struct resource *res) +{ + struct dma_slave_config slave_config = {}; + int ret; + + /* Prepare for TX DMA: */ + master->dma_tx = dma_request_slave_channel(dev, "tx"); + if (!master->dma_tx) { + dev_err(dev, "cannot get the TX DMA channel!\n"); + ret = -EINVAL; + goto err; + } + + slave_config.direction = DMA_MEM_TO_DEV; + slave_config.dst_addr = res->start + MXC_CSPITXDATA; + slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; + slave_config.dst_maxburst = spi_imx_get_fifosize(spi_imx) / 2; + ret = dmaengine_slave_config(master->dma_tx, &slave_config); + if (ret) { + dev_err(dev, "error in TX dma configuration.\n"); + goto err; + } + + /* Prepare for RX : */ + master->dma_rx = dma_request_slave_channel(dev, "rx"); + if (!master->dma_rx) { + dev_dbg(dev, "cannot get the DMA channel.\n"); + ret = -EINVAL; + goto err; + } + + slave_config.direction = DMA_DEV_TO_MEM; + slave_config.src_addr = res->start + MXC_CSPIRXDATA; + slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; + slave_config.src_maxburst = spi_imx_get_fifosize(spi_imx) / 2; + ret = dmaengine_slave_config(master->dma_rx, &slave_config); + if (ret) { + dev_err(dev, "error in RX dma configuration.\n"); + goto err; + } + + init_completion(&spi_imx->dma_rx_completion); + init_completion(&spi_imx->dma_tx_completion); + master->can_dma = spi_imx_can_dma; + master->max_dma_len = MAX_SDMA_BD_BYTES; + spi_imx->bitbang.master->flags = SPI_MASTER_MUST_RX | + SPI_MASTER_MUST_TX; + spi_imx->dma_is_inited = 1; + + return 0; +err: + spi_imx_sdma_exit(spi_imx); + return ret; +} + +static void spi_imx_dma_rx_callback(void *cookie) +{ + struct spi_imx_data *spi_imx = (struct spi_imx_data *)cookie; + + complete(&spi_imx->dma_rx_completion); +} + +static void spi_imx_dma_tx_callback(void *cookie) +{ + struct spi_imx_data *spi_imx = (struct spi_imx_data *)cookie; + + complete(&spi_imx->dma_tx_completion); +} + +static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx, + struct spi_transfer *transfer) +{ + struct dma_async_tx_descriptor *desc_tx = NULL, *desc_rx = NULL; + int ret; + u32 dma; + int left; + struct spi_master *master = spi_imx->bitbang.master; + struct sg_table *tx = &transfer->tx_sg, *rx = &transfer->rx_sg; + + if (tx) { + desc_tx = dmaengine_prep_slave_sg(master->dma_tx, + tx->sgl, tx->nents, DMA_TO_DEVICE, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc_tx) + goto no_dma; + + desc_tx->callback = spi_imx_dma_tx_callback; + desc_tx->callback_param = (void *)spi_imx; + dmaengine_submit(desc_tx); + } + + if (rx) { + desc_rx = dmaengine_prep_slave_sg(master->dma_rx, + rx->sgl, rx->nents, DMA_FROM_DEVICE, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc_rx) + goto no_dma; + + desc_rx->callback = spi_imx_dma_rx_callback; + desc_rx->callback_param = (void *)spi_imx; + dmaengine_submit(desc_rx); + } + + reinit_completion(&spi_imx->dma_rx_completion); + reinit_completion(&spi_imx->dma_tx_completion); + + /* Trigger the cspi module. */ + spi_imx->dma_finished = 0; + + dma = readl(spi_imx->base + MX51_ECSPI_DMA); + dma = dma & (~MX51_ECSPI_DMA_RXT_WML_MASK); + /* Change RX_DMA_LENGTH trigger dma fetch tail data */ + left = transfer->len % spi_imx->rxt_wml; + if (left) + writel(dma | (left << MX51_ECSPI_DMA_RXT_WML_OFFSET), + spi_imx->base + MX51_ECSPI_DMA); + spi_imx->devtype_data->trigger(spi_imx); + + dma_async_issue_pending(master->dma_tx); + dma_async_issue_pending(master->dma_rx); + /* Wait SDMA to finish the data transfer.*/ + ret = wait_for_completion_timeout(&spi_imx->dma_tx_completion, + IMX_DMA_TIMEOUT); + if (!ret) { + pr_warn("%s %s: I/O Error in DMA TX\n", + dev_driver_string(&master->dev), + dev_name(&master->dev)); + dmaengine_terminate_all(master->dma_tx); + } else { + ret = wait_for_completion_timeout(&spi_imx->dma_rx_completion, + IMX_DMA_TIMEOUT); + if (!ret) { + pr_warn("%s %s: I/O Error in DMA RX\n", + dev_driver_string(&master->dev), + dev_name(&master->dev)); + spi_imx->devtype_data->reset(spi_imx); + dmaengine_terminate_all(master->dma_rx); + } + writel(dma | + spi_imx->rxt_wml << MX51_ECSPI_DMA_RXT_WML_OFFSET, + spi_imx->base + MX51_ECSPI_DMA); + } + + spi_imx->dma_finished = 1; + spi_imx->devtype_data->trigger(spi_imx); + + if (!ret) + ret = -ETIMEDOUT; + else if (ret > 0) + ret = transfer->len; + + return ret; + +no_dma: + pr_warn_once("%s %s: DMA not available, falling back to PIO\n", + dev_driver_string(&master->dev), + dev_name(&master->dev)); + return -EAGAIN; +} + +static int spi_imx_pio_transfer(struct spi_device *spi, struct spi_transfer *transfer) { struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master); @@ -751,6 +999,24 @@ static int spi_imx_transfer(struct spi_device *spi, return transfer->len; } +static int spi_imx_transfer(struct spi_device *spi, + struct spi_transfer *transfer) +{ + int ret; + struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master); + + if (spi_imx->bitbang.master->can_dma && + spi_imx_can_dma(spi_imx->bitbang.master, spi, transfer)) { + spi_imx->usedma = true; + ret = spi_imx_dma_transfer(spi_imx, transfer); + if (ret != -EAGAIN) + return ret; + } + spi_imx->usedma = false; + + return spi_imx_pio_transfer(spi, transfer); +} + static int spi_imx_setup(struct spi_device *spi) { struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master); @@ -911,6 +1177,13 @@ static int spi_imx_probe(struct platform_device *pdev) goto out_put_per; spi_imx->spi_clk = clk_get_rate(spi_imx->clk_per); + /* + * Only validated on i.mx6 now, can remove the constrain if validated on + * other chips. + */ + if (spi_imx->devtype_data == &imx51_ecspi_devtype_data + && spi_imx_sdma_init(&pdev->dev, spi_imx, master, res)) + dev_err(&pdev->dev, "dma setup error,use pio instead\n"); spi_imx->devtype_data->reset(spi_imx); @@ -949,6 +1222,7 @@ static int spi_imx_remove(struct platform_device *pdev) writel(0, spi_imx->base + MXC_CSPICTRL); clk_unprepare(spi_imx->clk_ipg); clk_unprepare(spi_imx->clk_per); + spi_imx_sdma_exit(spi_imx); spi_master_put(master); return 0; -- 1.9.1 ^ permalink raw reply [flat|nested] 6+ messages in thread
* RE: [PATCH v6] spi: spi-imx: add DMA support 2014-10-21 1:06 ` [PATCH v6] spi: spi-imx: add DMA support Robin Gong @ 2014-10-21 2:14 ` Yibin Gong 0 siblings, 0 replies; 6+ messages in thread From: Yibin Gong @ 2014-10-21 2:14 UTC (permalink / raw) To: Yibin Gong, vinod.koul, dan.j.williams, andriy.shevchenko Cc: dmaengine, linux-kernel Sorry for sending the wrong patch set, please ignore... -----Original Message----- From: Robin Gong [mailto:b38343@freescale.com] Sent: Tuesday, October 21, 2014 9:06 AM To: vinod.koul@intel.com; dan.j.williams@intel.com; andriy.shevchenko@linux.intel.com Cc: dmaengine@vger.kernel.org; linux-kernel@vger.kernel.org; Gong Yibin-B38343 Subject: [PATCH v6] spi: spi-imx: add DMA support Enable DMA support on i.mx6. The read speed can increase from 600KB/s to 1.2MB/s on i.mx6q. You can disable or enable dma function in dts. If not set "dma-names" in dts, spi will use PIO mode. This patch only validate on i.mx6, not i.mx5, but encourage ones to apply this patch on i.mx5 since they share the same IP. Note: Sometime, there is a weid data in rxfifo after one full tx/rx transfer finish by DMA on i.mx6dl, so we disable dma functhion on i.mx6dl. Signed-off-by: Frank Li <Frank.Li@freescale.com> Signed-off-by: Robin Gong <b38343@freescale.com> --- Change from v5: 1. Update binding doc fsl-imx-cspi.txt. 2. remove usedma flag set from can_dma interface. Change from v4: 1. Enrich comments. 2. Remove the rxfifo workaround. The issue only exist on i.mx6dl, so disable dma function in dts. Change from v3: 1. Use spi core framwork to handle dump tx/rx buf 2. Add one workaround for weird data in rxfifo when one full transfer done. Change from v2: http://thread.gmane.org/gmane.linux.ports.arm.kernel/291722/focus=294363 1. Dma setup only for imx51-ecspi 2. Use one small dummy buffer(1 bd size) to templiy store data for meanless rx/tx, instead of malloc the actual transfer size. 3. Split spi_mx_sdma_transfer to smaller and easily to read. 4. Fix some code indent. --- .../devicetree/bindings/spi/fsl-imx-cspi.txt | 5 + drivers/spi/spi-imx.c | 286 ++++++++++++++++++++- 2 files changed, 285 insertions(+), 6 deletions(-) diff --git a/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt b/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt index 4256a6d..aad527b 100644 --- a/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt +++ b/Documentation/devicetree/bindings/spi/fsl-imx-cspi.txt @@ -7,6 +7,9 @@ Required properties: - interrupts : Should contain CSPI/eCSPI interrupt - fsl,spi-num-chipselects : Contains the number of the chipselect - cs-gpios : Specifies the gpio pins to be used for chipselects. +- dmas: DMA specifiers for tx and rx dma. See the DMA client binding, + Documentation/devicetree/bindings/dma/dma.txt +- dma-names: DMA request names should include "tx" and "rx" if present. Example: @@ -19,4 +22,6 @@ ecspi@70010000 { fsl,spi-num-chipselects = <2>; cs-gpios = <&gpio3 24 0>, /* GPIO3_24 */ <&gpio3 25 0>; /* GPIO3_25 */ + dmas = <&sdma 3 7 1>, <&sdma 4 7 2>; + dma-names = "rx", "tx"; }; diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c index 5daff20..3637847 100644 --- a/drivers/spi/spi-imx.c +++ b/drivers/spi/spi-imx.c @@ -21,6 +21,8 @@ #include <linux/clk.h> #include <linux/completion.h> #include <linux/delay.h> +#include <linux/dmaengine.h> +#include <linux/dma-mapping.h> #include <linux/err.h> #include <linux/gpio.h> #include <linux/interrupt.h> @@ -37,6 +39,7 @@ #include <linux/of_device.h> #include <linux/of_gpio.h> +#include <linux/platform_data/dma-imx.h> #include <linux/platform_data/spi-imx.h> #define DRIVER_NAME "spi_imx" @@ -51,6 +54,9 @@ #define MXC_INT_RR (1 << 0) /* Receive data ready interrupt */ #define MXC_INT_TE (1 << 1) /* Transmit FIFO empty interrupt */ +/* The maximum bytes that a sdma BD can transfer.*/ #define +MAX_SDMA_BD_BYTES (1 << 15) #define IMX_DMA_TIMEOUT +(msecs_to_jiffies(3000)) struct spi_imx_config { unsigned int speed_hz; unsigned int bpw; @@ -95,6 +101,16 @@ struct spi_imx_data { const void *tx_buf; unsigned int txfifo; /* number of words pushed in tx FIFO */ + /* DMA */ + unsigned int dma_is_inited; + unsigned int dma_finished; + bool usedma; + u32 rx_wml; + u32 tx_wml; + u32 rxt_wml; + struct completion dma_rx_completion; + struct completion dma_tx_completion; + const struct spi_imx_devtype_data *devtype_data; int chipselect[0]; }; @@ -181,9 +197,21 @@ static unsigned int spi_imx_clkdiv_2(unsigned int fin, return 7; } +static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi, + struct spi_transfer *transfer) +{ + struct spi_imx_data *spi_imx = spi_master_get_devdata(master); + + if (spi_imx->dma_is_inited && (transfer->len > spi_imx->rx_wml) + && (transfer->len > spi_imx->tx_wml)) + return true; + return false; +} + #define MX51_ECSPI_CTRL 0x08 #define MX51_ECSPI_CTRL_ENABLE (1 << 0) #define MX51_ECSPI_CTRL_XCH (1 << 2) +#define MX51_ECSPI_CTRL_SMC (1 << 3) #define MX51_ECSPI_CTRL_MODE_MASK (0xf << 4) #define MX51_ECSPI_CTRL_POSTDIV_OFFSET 8 #define MX51_ECSPI_CTRL_PREDIV_OFFSET 12 @@ -201,6 +229,18 @@ static unsigned int spi_imx_clkdiv_2(unsigned int fin, #define MX51_ECSPI_INT_TEEN (1 << 0) #define MX51_ECSPI_INT_RREN (1 << 3) +#define MX51_ECSPI_DMA 0x14 +#define MX51_ECSPI_DMA_TX_WML_OFFSET 0 +#define MX51_ECSPI_DMA_TX_WML_MASK 0x3F +#define MX51_ECSPI_DMA_RX_WML_OFFSET 16 +#define MX51_ECSPI_DMA_RX_WML_MASK (0x3F << 16) +#define MX51_ECSPI_DMA_RXT_WML_OFFSET 24 +#define MX51_ECSPI_DMA_RXT_WML_MASK (0x3F << 24) + +#define MX51_ECSPI_DMA_TEDEN_OFFSET 7 +#define MX51_ECSPI_DMA_RXDEN_OFFSET 23 +#define MX51_ECSPI_DMA_RXTDEN_OFFSET 31 + #define MX51_ECSPI_STAT 0x18 #define MX51_ECSPI_STAT_RR (1 << 3) @@ -257,17 +297,22 @@ static void __maybe_unused mx51_ecspi_intctrl(struct spi_imx_data *spi_imx, int static void __maybe_unused mx51_ecspi_trigger(struct spi_imx_data *spi_imx) { - u32 reg; - - reg = readl(spi_imx->base + MX51_ECSPI_CTRL); - reg |= MX51_ECSPI_CTRL_XCH; + u32 reg = readl(spi_imx->base + MX51_ECSPI_CTRL); + + if (!spi_imx->usedma) + reg |= MX51_ECSPI_CTRL_XCH; + else if (!spi_imx->dma_finished) + reg |= MX51_ECSPI_CTRL_SMC; + else + reg &= ~MX51_ECSPI_CTRL_SMC; writel(reg, spi_imx->base + MX51_ECSPI_CTRL); } static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx, struct spi_imx_config *config) { - u32 ctrl = MX51_ECSPI_CTRL_ENABLE, cfg = 0; + u32 ctrl = MX51_ECSPI_CTRL_ENABLE, cfg = 0, dma = 0; + u32 tx_wml_cfg, rx_wml_cfg, rxt_wml_cfg; u32 clk = config->speed_hz, delay; /* @@ -319,6 +364,30 @@ static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx, else /* SCLK is _very_ slow */ usleep_range(delay, delay + 10); + /* + * Configure the DMA register: setup the watermark + * and enable DMA request. + */ + if (spi_imx->dma_is_inited) { + dma = readl(spi_imx->base + MX51_ECSPI_DMA); + + spi_imx->tx_wml = spi_imx_get_fifosize(spi_imx) / 2; + spi_imx->rx_wml = spi_imx_get_fifosize(spi_imx) / 2; + spi_imx->rxt_wml = spi_imx_get_fifosize(spi_imx) / 2; + rx_wml_cfg = spi_imx->rx_wml << MX51_ECSPI_DMA_RX_WML_OFFSET; + tx_wml_cfg = spi_imx->tx_wml << MX51_ECSPI_DMA_TX_WML_OFFSET; + rxt_wml_cfg = spi_imx->rxt_wml << MX51_ECSPI_DMA_RXT_WML_OFFSET; + dma = (dma & ~MX51_ECSPI_DMA_TX_WML_MASK + & ~MX51_ECSPI_DMA_RX_WML_MASK + & ~MX51_ECSPI_DMA_RXT_WML_MASK) + | rx_wml_cfg | tx_wml_cfg | rxt_wml_cfg + |(1 << MX51_ECSPI_DMA_TEDEN_OFFSET) + |(1 << MX51_ECSPI_DMA_RXDEN_OFFSET) + |(1 << MX51_ECSPI_DMA_RXTDEN_OFFSET); + + writel(dma, spi_imx->base + MX51_ECSPI_DMA); + } + return 0; } @@ -730,7 +799,186 @@ static int spi_imx_setupxfer(struct spi_device *spi, return 0; } -static int spi_imx_transfer(struct spi_device *spi, +static void spi_imx_sdma_exit(struct spi_imx_data *spi_imx) { + struct spi_master *master = spi_imx->bitbang.master; + + if (master->dma_rx) { + dma_release_channel(master->dma_rx); + master->dma_rx = NULL; + } + + if (master->dma_tx) { + dma_release_channel(master->dma_tx); + master->dma_tx = NULL; + } + + spi_imx->dma_is_inited = 0; +} + +static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx, + struct spi_master *master, + const struct resource *res) +{ + struct dma_slave_config slave_config = {}; + int ret; + + /* Prepare for TX DMA: */ + master->dma_tx = dma_request_slave_channel(dev, "tx"); + if (!master->dma_tx) { + dev_err(dev, "cannot get the TX DMA channel!\n"); + ret = -EINVAL; + goto err; + } + + slave_config.direction = DMA_MEM_TO_DEV; + slave_config.dst_addr = res->start + MXC_CSPITXDATA; + slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; + slave_config.dst_maxburst = spi_imx_get_fifosize(spi_imx) / 2; + ret = dmaengine_slave_config(master->dma_tx, &slave_config); + if (ret) { + dev_err(dev, "error in TX dma configuration.\n"); + goto err; + } + + /* Prepare for RX : */ + master->dma_rx = dma_request_slave_channel(dev, "rx"); + if (!master->dma_rx) { + dev_dbg(dev, "cannot get the DMA channel.\n"); + ret = -EINVAL; + goto err; + } + + slave_config.direction = DMA_DEV_TO_MEM; + slave_config.src_addr = res->start + MXC_CSPIRXDATA; + slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; + slave_config.src_maxburst = spi_imx_get_fifosize(spi_imx) / 2; + ret = dmaengine_slave_config(master->dma_rx, &slave_config); + if (ret) { + dev_err(dev, "error in RX dma configuration.\n"); + goto err; + } + + init_completion(&spi_imx->dma_rx_completion); + init_completion(&spi_imx->dma_tx_completion); + master->can_dma = spi_imx_can_dma; + master->max_dma_len = MAX_SDMA_BD_BYTES; + spi_imx->bitbang.master->flags = SPI_MASTER_MUST_RX | + SPI_MASTER_MUST_TX; + spi_imx->dma_is_inited = 1; + + return 0; +err: + spi_imx_sdma_exit(spi_imx); + return ret; +} + +static void spi_imx_dma_rx_callback(void *cookie) { + struct spi_imx_data *spi_imx = (struct spi_imx_data *)cookie; + + complete(&spi_imx->dma_rx_completion); +} + +static void spi_imx_dma_tx_callback(void *cookie) { + struct spi_imx_data *spi_imx = (struct spi_imx_data *)cookie; + + complete(&spi_imx->dma_tx_completion); +} + +static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx, + struct spi_transfer *transfer) +{ + struct dma_async_tx_descriptor *desc_tx = NULL, *desc_rx = NULL; + int ret; + u32 dma; + int left; + struct spi_master *master = spi_imx->bitbang.master; + struct sg_table *tx = &transfer->tx_sg, *rx = &transfer->rx_sg; + + if (tx) { + desc_tx = dmaengine_prep_slave_sg(master->dma_tx, + tx->sgl, tx->nents, DMA_TO_DEVICE, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc_tx) + goto no_dma; + + desc_tx->callback = spi_imx_dma_tx_callback; + desc_tx->callback_param = (void *)spi_imx; + dmaengine_submit(desc_tx); + } + + if (rx) { + desc_rx = dmaengine_prep_slave_sg(master->dma_rx, + rx->sgl, rx->nents, DMA_FROM_DEVICE, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc_rx) + goto no_dma; + + desc_rx->callback = spi_imx_dma_rx_callback; + desc_rx->callback_param = (void *)spi_imx; + dmaengine_submit(desc_rx); + } + + reinit_completion(&spi_imx->dma_rx_completion); + reinit_completion(&spi_imx->dma_tx_completion); + + /* Trigger the cspi module. */ + spi_imx->dma_finished = 0; + + dma = readl(spi_imx->base + MX51_ECSPI_DMA); + dma = dma & (~MX51_ECSPI_DMA_RXT_WML_MASK); + /* Change RX_DMA_LENGTH trigger dma fetch tail data */ + left = transfer->len % spi_imx->rxt_wml; + if (left) + writel(dma | (left << MX51_ECSPI_DMA_RXT_WML_OFFSET), + spi_imx->base + MX51_ECSPI_DMA); + spi_imx->devtype_data->trigger(spi_imx); + + dma_async_issue_pending(master->dma_tx); + dma_async_issue_pending(master->dma_rx); + /* Wait SDMA to finish the data transfer.*/ + ret = wait_for_completion_timeout(&spi_imx->dma_tx_completion, + IMX_DMA_TIMEOUT); + if (!ret) { + pr_warn("%s %s: I/O Error in DMA TX\n", + dev_driver_string(&master->dev), + dev_name(&master->dev)); + dmaengine_terminate_all(master->dma_tx); + } else { + ret = wait_for_completion_timeout(&spi_imx->dma_rx_completion, + IMX_DMA_TIMEOUT); + if (!ret) { + pr_warn("%s %s: I/O Error in DMA RX\n", + dev_driver_string(&master->dev), + dev_name(&master->dev)); + spi_imx->devtype_data->reset(spi_imx); + dmaengine_terminate_all(master->dma_rx); + } + writel(dma | + spi_imx->rxt_wml << MX51_ECSPI_DMA_RXT_WML_OFFSET, + spi_imx->base + MX51_ECSPI_DMA); + } + + spi_imx->dma_finished = 1; + spi_imx->devtype_data->trigger(spi_imx); + + if (!ret) + ret = -ETIMEDOUT; + else if (ret > 0) + ret = transfer->len; + + return ret; + +no_dma: + pr_warn_once("%s %s: DMA not available, falling back to PIO\n", + dev_driver_string(&master->dev), + dev_name(&master->dev)); + return -EAGAIN; +} + +static int spi_imx_pio_transfer(struct spi_device *spi, struct spi_transfer *transfer) { struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master); @@ -751,6 +999,24 @@ static int spi_imx_transfer(struct spi_device *spi, return transfer->len; } +static int spi_imx_transfer(struct spi_device *spi, + struct spi_transfer *transfer) +{ + int ret; + struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master); + + if (spi_imx->bitbang.master->can_dma && + spi_imx_can_dma(spi_imx->bitbang.master, spi, transfer)) { + spi_imx->usedma = true; + ret = spi_imx_dma_transfer(spi_imx, transfer); + if (ret != -EAGAIN) + return ret; + } + spi_imx->usedma = false; + + return spi_imx_pio_transfer(spi, transfer); } + static int spi_imx_setup(struct spi_device *spi) { struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master); @@ -911,6 +1177,13 @@ static int spi_imx_probe(struct platform_device *pdev) goto out_put_per; spi_imx->spi_clk = clk_get_rate(spi_imx->clk_per); + /* + * Only validated on i.mx6 now, can remove the constrain if validated on + * other chips. + */ + if (spi_imx->devtype_data == &imx51_ecspi_devtype_data + && spi_imx_sdma_init(&pdev->dev, spi_imx, master, res)) + dev_err(&pdev->dev, "dma setup error,use pio instead\n"); spi_imx->devtype_data->reset(spi_imx); @@ -949,6 +1222,7 @@ static int spi_imx_remove(struct platform_device *pdev) writel(0, spi_imx->base + MXC_CSPICTRL); clk_unprepare(spi_imx->clk_ipg); clk_unprepare(spi_imx->clk_per); + spi_imx_sdma_exit(spi_imx); spi_master_put(master); return 0; -- 1.9.1 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v4 0/3] dma: imx-sdma: add support for sdma memory copy 2014-10-21 1:06 [PATCH v2] ARM: dts: imx6dl: disable dma support for spi on i.mx6dl Robin Gong 2014-10-21 1:06 ` [PATCH v1] ARM: imx6: add pm_power_off support for i.mx6 chips Robin Gong 2014-10-21 1:06 ` [PATCH v6] spi: spi-imx: add DMA support Robin Gong @ 2014-10-21 1:06 ` Robin Gong 2 siblings, 0 replies; 6+ messages in thread From: Robin Gong @ 2014-10-21 1:06 UTC (permalink / raw) To: vinod.koul, dan.j.williams, andriy.shevchenko Cc: dmaengine, linux-kernel, b38343 Add memory copy interface to sdma driver, the patch set is based on v3: http://www.spinics.net/lists/dmaengine/msg00850.html. change from v3: 1.split two patches from v3 patch for Vinod's comments. change from v2: 1.remove redundant check for bus width. change from v1: 1. correct some printk format, such as %pad for dma_addr_t 2. split duplicated code in prep_dma_memcpy and prep_dma_sg to make code clean Robin Gong (3): dma: imx-sdma: add support for sdma memory copy dma: imx-sdma: correct print format dma: imx-sdma: reorg code to make code clean drivers/dma/imx-sdma.c | 247 +++++++++++++++++++++++++++++++++++++------------ 1 file changed, 190 insertions(+), 57 deletions(-) -- 1.9.1 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v4 0/3] dma: imx-sdma: add support for sdma memory copy @ 2014-10-21 1:09 Robin Gong 0 siblings, 0 replies; 6+ messages in thread From: Robin Gong @ 2014-10-21 1:09 UTC (permalink / raw) To: vinod.koul, dan.j.williams, andriy.shevchenko Cc: dmaengine, linux-kernel, b38343 Add memory copy interface to sdma driver, the patch set is based on v3: http://www.spinics.net/lists/dmaengine/msg00850.html. change from v3: 1.split two patches from v3 patch for Vinod's comments. change from v2: 1.remove redundant check for bus width. change from v1: 1. correct some printk format, such as %pad for dma_addr_t 2. split duplicated code in prep_dma_memcpy and prep_dma_sg to make code clean Robin Gong (3): dma: imx-sdma: add support for sdma memory copy dma: imx-sdma: correct print format dma: imx-sdma: reorg code to make code clean drivers/dma/imx-sdma.c | 247 +++++++++++++++++++++++++++++++++++++------------ 1 file changed, 190 insertions(+), 57 deletions(-) -- 1.9.1 ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2014-10-21 2:15 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2014-10-21 1:06 [PATCH v2] ARM: dts: imx6dl: disable dma support for spi on i.mx6dl Robin Gong 2014-10-21 1:06 ` [PATCH v1] ARM: imx6: add pm_power_off support for i.mx6 chips Robin Gong 2014-10-21 1:06 ` [PATCH v6] spi: spi-imx: add DMA support Robin Gong 2014-10-21 2:14 ` Yibin Gong 2014-10-21 1:06 ` [PATCH v4 0/3] dma: imx-sdma: add support for sdma memory copy Robin Gong 2014-10-21 1:09 Robin Gong
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