[PATCH v4] dmaengine: mxs-dma: add dma support for i.MX23/28
Shawn Guo
shawn.guo at freescale.com
Fri Feb 25 02:34:19 EST 2011
This patch adds dma support for Freescale MXS-based SoC i.MX23/28,
including apbh-dma and apbx-dma.
* apbh-dma and apbx-dma are supported in the driver as two mxs-dma
instances.
* apbh-dma is different between mx23 and mx28, hardware version
register is used to differentiate.
* mxs-dma supports pio function besides data transfer. The driver
uses dma_data_direction DMA_NONE to identify the pio mode, and
steals sgl and sg_len to get pio words and numbers from clients.
* mxs dmaengine has some very specific features, like sense function
and the special NAND support (nand_lock, nand_wait4ready). These
are too specific to implemented in generic dmaengine driver.
* The driver refers to imx-sdma and only a single descriptor is
statically assigned to each channel.
Signed-off-by: Shawn Guo <shawn.guo at freescale.com>
---
arch/arm/mach-mxs/include/mach/dma.h | 26 ++
drivers/dma/Kconfig | 8 +
drivers/dma/Makefile | 1 +
drivers/dma/mxs-dma.c | 723 ++++++++++++++++++++++++++++++++++
4 files changed, 758 insertions(+), 0 deletions(-)
create mode 100644 arch/arm/mach-mxs/include/mach/dma.h
create mode 100644 drivers/dma/mxs-dma.c
diff --git a/arch/arm/mach-mxs/include/mach/dma.h b/arch/arm/mach-mxs/include/mach/dma.h
new file mode 100644
index 0000000..7f4aeea
--- /dev/null
+++ b/arch/arm/mach-mxs/include/mach/dma.h
@@ -0,0 +1,26 @@
+/*
+ * Copyright 2011 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * 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.
+ */
+
+#ifndef __MACH_MXS_DMA_H__
+#define __MACH_MXS_DMA_H__
+
+struct mxs_dma_data {
+ int chan_irq;
+};
+
+static inline int mxs_dma_is_apbh(struct dma_chan *chan)
+{
+ return !strcmp(dev_name(chan->device->dev), "mxs-dma-apbh");
+}
+
+static inline int mxs_dma_is_apbx(struct dma_chan *chan)
+{
+ return !strcmp(dev_name(chan->device->dev), "mxs-dma-apbx");
+}
+
+#endif /* __MACH_MXS_DMA_H__ */
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 1c28816..76f6472 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -227,6 +227,14 @@ config IMX_DMA
Support the i.MX DMA engine. This engine is integrated into
Freescale i.MX1/21/27 chips.
+config MXS_DMA
+ bool "MXS DMA support"
+ depends on SOC_IMX23 || SOC_IMX28
+ select DMA_ENGINE
+ help
+ Support the MXS DMA engine. This engine including APBH-DMA
+ and APBX-DMA is integrated into Freescale i.MX23/28 chips.
+
config DMA_ENGINE
bool
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index 64b21f5..802b557 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -23,6 +23,7 @@ obj-$(CONFIG_COH901318) += coh901318.o coh901318_lli.o
obj-$(CONFIG_AMCC_PPC440SPE_ADMA) += ppc4xx/
obj-$(CONFIG_IMX_SDMA) += imx-sdma.o
obj-$(CONFIG_IMX_DMA) += imx-dma.o
+obj-$(CONFIG_MXS_DMA) += mxs-dma.o
obj-$(CONFIG_TIMB_DMA) += timb_dma.o
obj-$(CONFIG_STE_DMA40) += ste_dma40.o ste_dma40_ll.o
obj-$(CONFIG_PL330_DMA) += pl330.o
diff --git a/drivers/dma/mxs-dma.c b/drivers/dma/mxs-dma.c
new file mode 100644
index 0000000..94fcc6d
--- /dev/null
+++ b/drivers/dma/mxs-dma.c
@@ -0,0 +1,723 @@
+/*
+ * Copyright 2011 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * Refer to drivers/dma/imx-sdma.c
+ *
+ * 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.
+ */
+
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/clk.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
+#include <linux/semaphore.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/dmaengine.h>
+#include <linux/delay.h>
+
+#include <asm/irq.h>
+#include <mach/mxs.h>
+#include <mach/dma.h>
+#include <mach/common.h>
+
+/*
+ * NOTE: The term "PIO" throughout the mxs-dma implementation means
+ * PIO mode of mxs apbh-dma and apbx-dma. With this working mode,
+ * dma can program the controller registers of peripheral devices.
+ */
+
+#define MXS_DMA_APBH 0
+#define MXS_DMA_APBX 1
+#define dma_is_apbh() (mxs_dma->dev_id == MXS_DMA_APBH)
+
+#define APBH_VERSION_LATEST 3
+#define apbh_is_old() (mxs_dma->version < APBH_VERSION_LATEST)
+
+#define HW_APBHX_CTRL0 0x000
+#define BM_APBH_CTRL0_APB_BURST8_EN (1 << 29)
+#define BM_APBH_CTRL0_APB_BURST_EN (1 << 28)
+#define BP_APBH_CTRL0_CLKGATE_CHANNEL 8
+#define BP_APBH_CTRL0_RESET_CHANNEL 16
+#define HW_APBHX_CTRL1 0x010
+#define HW_APBHX_CTRL2 0x020
+#define HW_APBHX_CHANNEL_CTRL 0x030
+#define BP_APBHX_CHANNEL_CTRL_RESET_CHANNEL 16
+#define HW_APBH_VERSION (cpu_is_mx23() ? 0x3f0 : 0x800)
+#define HW_APBX_VERSION 0x800
+#define BP_APBHX_VERSION_MAJOR 24
+#define HW_APBHX_CHn_NXTCMDAR(n) \
+ (((dma_is_apbh() && apbh_is_old()) ? 0x050 : 0x110) + (n) * 0x70)
+#define HW_APBHX_CHn_SEMA(n) \
+ (((dma_is_apbh() && apbh_is_old()) ? 0x080 : 0x140) + (n) * 0x70)
+
+/*
+ * ccw bits definitions
+ *
+ * COMMAND: 0..1 (2)
+ * CHAIN: 2 (1)
+ * IRQ: 3 (1)
+ * NAND_LOCK: 4 (1) - not implemented
+ * NAND_WAIT4READY: 5 (1) - not implemented
+ * DEC_SEM: 6 (1)
+ * WAIT4END: 7 (1)
+ * HALT_ON_TERMINATE: 8 (1)
+ * TERMINATE_FLUSH: 9 (1)
+ * RESERVED: 10..11 (2)
+ * PIO_NUM: 12..15 (4)
+ */
+#define BP_CCW_COMMAND 0
+#define BM_CCW_COMMAND (3 << 0)
+#define CCW_CHAIN (1 << 2)
+#define CCW_IRQ (1 << 3)
+#define CCW_DEC_SEM (1 << 6)
+#define CCW_WAIT4END (1 << 7)
+#define CCW_HALT_ON_TERM (1 << 8)
+#define CCW_TERM_FLUSH (1 << 9)
+#define BP_CCW_PIO_NUM 12
+#define BM_CCW_PIO_NUM (0xf << 12)
+
+#define BF_CCW(value, field) (((value) << BP_CCW_##field) & BM_CCW_##field)
+
+#define MXS_DMA_CMD_NO_XFER 0
+#define MXS_DMA_CMD_WRITE 1
+#define MXS_DMA_CMD_READ 2
+#define MXS_DMA_CMD_DMA_SENSE 3 /* not implemented */
+
+struct mxs_dma_ccw {
+ u32 next;
+ u16 bits;
+ u16 xfer_bytes;
+#define MAX_XFER_BYTES 0xff00
+ u32 bufaddr;
+#define MXS_PIO_WORDS 16
+ u32 pio_words[MXS_PIO_WORDS];
+};
+
+#define NUM_CCW (int)(PAGE_SIZE / sizeof(struct mxs_dma_ccw))
+
+struct mxs_dma_chan {
+ struct mxs_dma_engine *mxs_dma;
+ struct dma_chan chan;
+ struct dma_async_tx_descriptor desc;
+ struct tasklet_struct tasklet;
+ int chan_irq;
+ struct mxs_dma_ccw *ccw;
+ dma_addr_t ccw_phys;
+ dma_cookie_t last_completed;
+ enum dma_status status;
+ unsigned int flags;
+#define MXS_DMA_SG_LOOP (1 << 0)
+};
+
+#define MXS_DMA_CHANNELS 16
+#define MXS_DMA_CHANNELS_MASK 0xffff
+
+struct mxs_dma_engine {
+ int dev_id;
+ unsigned int version;
+ void __iomem *base;
+ struct clk *clk;
+ struct dma_device dma_device;
+ struct device_dma_parameters dma_parms;
+ struct mxs_dma_chan mxs_chans[MXS_DMA_CHANNELS];
+};
+
+static void mxs_dma_reset_chan(struct mxs_dma_chan *mxs_chan)
+{
+ struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
+ int chan_id = mxs_chan->chan.chan_id;
+
+ if (dma_is_apbh() && apbh_is_old())
+ writel(1 << (chan_id + BP_APBH_CTRL0_RESET_CHANNEL),
+ mxs_dma->base + HW_APBHX_CTRL0 + MXS_SET_ADDR);
+ else
+ writel(1 << (chan_id + BP_APBHX_CHANNEL_CTRL_RESET_CHANNEL),
+ mxs_dma->base + HW_APBHX_CHANNEL_CTRL + MXS_SET_ADDR);
+}
+
+static void mxs_dma_enable_chan(struct mxs_dma_chan *mxs_chan)
+{
+ struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
+ int chan_id = mxs_chan->chan.chan_id;
+
+ /* set cmd_addr up */
+ writel(mxs_chan->ccw_phys,
+ mxs_dma->base + HW_APBHX_CHn_NXTCMDAR(chan_id));
+
+ /* enable apbh channel clock */
+ if (dma_is_apbh()) {
+ if (apbh_is_old())
+ writel(1 << (chan_id + BP_APBH_CTRL0_CLKGATE_CHANNEL),
+ mxs_dma->base + HW_APBHX_CTRL0 + MXS_CLR_ADDR);
+ else
+ writel(1 << chan_id,
+ mxs_dma->base + HW_APBHX_CTRL0 + MXS_CLR_ADDR);
+ }
+
+ /* write 1 to SEMA to kick off the channel */
+ writel(1, mxs_dma->base + HW_APBHX_CHn_SEMA(chan_id));
+}
+
+static void mxs_dma_disable_chan(struct mxs_dma_chan *mxs_chan)
+{
+ struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
+ int chan_id = mxs_chan->chan.chan_id;
+
+ /* disable apbh channel clock */
+ if (dma_is_apbh()) {
+ if (apbh_is_old())
+ writel(1 << (chan_id + BP_APBH_CTRL0_CLKGATE_CHANNEL),
+ mxs_dma->base + HW_APBHX_CTRL0 + MXS_SET_ADDR);
+ else
+ writel(1 << chan_id,
+ mxs_dma->base + HW_APBHX_CTRL0 + MXS_SET_ADDR);
+ }
+
+ mxs_chan->status = DMA_SUCCESS;
+}
+
+static void mxs_dma_pause_chan(struct mxs_dma_chan *mxs_chan)
+{
+ struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
+ int chan_id = mxs_chan->chan.chan_id;
+
+ /* freeze the channel */
+ if (dma_is_apbh() && apbh_is_old())
+ writel(1 << chan_id,
+ mxs_dma->base + HW_APBHX_CTRL0 + MXS_SET_ADDR);
+ else
+ writel(1 << chan_id,
+ mxs_dma->base + HW_APBHX_CHANNEL_CTRL + MXS_SET_ADDR);
+
+ mxs_chan->status = DMA_PAUSED;
+}
+
+static void mxs_dma_resume_chan(struct mxs_dma_chan *mxs_chan)
+{
+ struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
+ int chan_id = mxs_chan->chan.chan_id;
+
+ /* unfreeze the channel */
+ if (dma_is_apbh() && apbh_is_old())
+ writel(1 << chan_id,
+ mxs_dma->base + HW_APBHX_CTRL0 + MXS_CLR_ADDR);
+ else
+ writel(1 << chan_id,
+ mxs_dma->base + HW_APBHX_CHANNEL_CTRL + MXS_CLR_ADDR);
+
+ mxs_chan->status = DMA_IN_PROGRESS;
+}
+
+static dma_cookie_t mxs_dma_assign_cookie(struct mxs_dma_chan *mxs_chan)
+{
+ dma_cookie_t cookie = mxs_chan->chan.cookie;
+
+ if (++cookie < 0)
+ cookie = 1;
+
+ mxs_chan->chan.cookie = cookie;
+ mxs_chan->desc.cookie = cookie;
+
+ return cookie;
+}
+
+static struct mxs_dma_chan *to_mxs_dma_chan(struct dma_chan *chan)
+{
+ return container_of(chan, struct mxs_dma_chan, chan);
+}
+
+static dma_cookie_t mxs_dma_tx_submit(struct dma_async_tx_descriptor *tx)
+{
+ struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(tx->chan);
+
+ mxs_dma_enable_chan(mxs_chan);
+
+ return mxs_dma_assign_cookie(mxs_chan);
+}
+
+static void mxs_dma_tasklet(unsigned long data)
+{
+ struct mxs_dma_chan *mxs_chan = (struct mxs_dma_chan *) data;
+
+ if (mxs_chan->desc.callback)
+ mxs_chan->desc.callback(mxs_chan->desc.callback_param);
+}
+
+static irqreturn_t mxs_dma_int_handler(int irq, void *dev_id)
+{
+ struct mxs_dma_engine *mxs_dma = dev_id;
+ u32 stat1, stat2;
+
+ /* completion status */
+ stat1 = readl(mxs_dma->base + HW_APBHX_CTRL1);
+ stat1 &= MXS_DMA_CHANNELS_MASK;
+ writel(stat1, mxs_dma->base + HW_APBHX_CTRL1 + MXS_CLR_ADDR);
+
+ /* error status */
+ stat2 = readl(mxs_dma->base + HW_APBHX_CTRL2);
+ writel(stat2, mxs_dma->base + HW_APBHX_CTRL2 + MXS_CLR_ADDR);
+
+ /*
+ * When both completion and error of termination bits set at the
+ * same time, we do not take it as an error. IOW, it only becomes
+ * an error we need to handler here in case of ether it's (1) an bus
+ * error or (2) a termination error with no completion.
+ */
+ stat2 = ((stat2 >> MXS_DMA_CHANNELS) & stat2) | /* (1) */
+ (~(stat2 >> MXS_DMA_CHANNELS) & stat2 & ~stat1); /* (2) */
+
+ /* combine error and completion status for checking */
+ stat1 = (stat2 << MXS_DMA_CHANNELS) | stat1;
+ while (stat1) {
+ int channel = fls(stat1) - 1;
+ struct mxs_dma_chan *mxs_chan =
+ &mxs_dma->mxs_chans[channel % MXS_DMA_CHANNELS];
+
+ if (channel >= MXS_DMA_CHANNELS) {
+ dev_dbg(mxs_dma->dma_device.dev,
+ "%s: error in channel %d\n", __func__,
+ channel - MXS_DMA_CHANNELS);
+ mxs_chan->status = DMA_ERROR;
+ mxs_dma_reset_chan(mxs_chan);
+ } else {
+ if (mxs_chan->flags & MXS_DMA_SG_LOOP)
+ mxs_chan->status = DMA_IN_PROGRESS;
+ else
+ mxs_chan->status = DMA_SUCCESS;
+ }
+
+ stat1 &= ~(1 << channel);
+
+ if (mxs_chan->status == DMA_SUCCESS)
+ mxs_chan->last_completed = mxs_chan->desc.cookie;
+
+ /* schedule tasklet on this channel */
+ tasklet_schedule(&mxs_chan->tasklet);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static int mxs_dma_alloc_chan_resources(struct dma_chan *chan)
+{
+ struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
+ struct mxs_dma_data *data = chan->private;
+ struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
+ int ret;
+
+ if (!data)
+ return -EINVAL;
+
+ mxs_chan->chan_irq = data->chan_irq;
+
+ mxs_chan->ccw = dma_alloc_coherent(mxs_dma->dma_device.dev, PAGE_SIZE,
+ &mxs_chan->ccw_phys, GFP_KERNEL);
+ if (!mxs_chan->ccw) {
+ ret = -ENOMEM;
+ goto err_alloc;
+ }
+
+ memset(mxs_chan->ccw, 0, PAGE_SIZE);
+
+ ret = request_irq(mxs_chan->chan_irq, mxs_dma_int_handler,
+ 0, "mxs-dma", mxs_dma);
+ if (ret)
+ goto err_irq;
+
+ ret = clk_enable(mxs_dma->clk);
+ if (ret)
+ goto err_clk;
+
+ mxs_dma_reset_chan(mxs_chan);
+
+ dma_async_tx_descriptor_init(&mxs_chan->desc, chan);
+ mxs_chan->desc.tx_submit = mxs_dma_tx_submit;
+
+ /* the descriptor is ready */
+ async_tx_ack(&mxs_chan->desc);
+
+ return 0;
+
+err_clk:
+ free_irq(mxs_chan->chan_irq, mxs_dma);
+err_irq:
+ dma_free_coherent(mxs_dma->dma_device.dev, PAGE_SIZE,
+ mxs_chan->ccw, mxs_chan->ccw_phys);
+err_alloc:
+ return ret;
+}
+
+static void mxs_dma_free_chan_resources(struct dma_chan *chan)
+{
+ struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
+ struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
+
+ mxs_dma_disable_chan(mxs_chan);
+
+ free_irq(mxs_chan->chan_irq, mxs_dma);
+
+ dma_free_coherent(mxs_dma->dma_device.dev, PAGE_SIZE,
+ mxs_chan->ccw, mxs_chan->ccw_phys);
+
+ clk_disable(mxs_dma->clk);
+}
+
+static struct dma_async_tx_descriptor *mxs_dma_prep_slave_sg(
+ struct dma_chan *chan, struct scatterlist *sgl,
+ unsigned int sg_len, enum dma_data_direction direction,
+ unsigned long append)
+{
+ struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
+ struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
+ struct mxs_dma_ccw *ccw;
+ struct scatterlist *sg;
+ int i, j;
+ u32 *pio;
+ static int idx = 0;
+
+ if (mxs_chan->status == DMA_IN_PROGRESS && !append)
+ return NULL;
+
+ if (sg_len + (append ? idx : 0) > NUM_CCW) {
+ dev_err(mxs_dma->dma_device.dev,
+ "maximum number of sg exceeded: %d > %d\n",
+ sg_len, NUM_CCW);
+ goto err_out;
+ }
+
+ mxs_chan->status = DMA_IN_PROGRESS;
+ mxs_chan->flags = 0;
+
+ /*
+ * If the sg is prepared with append flag set, the sg
+ * will be appended to the last prepared sg.
+ */
+ if (append) {
+ BUG_ON(idx < 1);
+ ccw = &mxs_chan->ccw[idx - 1];
+ ccw->next = mxs_chan->ccw_phys + sizeof(*ccw) * idx;
+ ccw->bits |= CCW_CHAIN;
+ ccw->bits &= ~CCW_IRQ;
+ ccw->bits &= ~CCW_DEC_SEM;
+ ccw->bits &= ~CCW_WAIT4END;
+ } else {
+ idx = 0;
+ }
+
+ if (direction == DMA_NONE) {
+ ccw = &mxs_chan->ccw[idx++];
+ pio = (u32 *) sgl;
+
+ for (j = 0; j < sg_len;)
+ ccw->pio_words[j++] = *pio++;
+
+ ccw->bits = 0;
+ ccw->bits |= CCW_IRQ;
+ ccw->bits |= CCW_DEC_SEM;
+ ccw->bits |= CCW_WAIT4END;
+ ccw->bits |= CCW_HALT_ON_TERM;
+ ccw->bits |= CCW_TERM_FLUSH;
+ ccw->bits |= BF_CCW(sg_len, PIO_NUM);
+ ccw->bits |= BF_CCW(MXS_DMA_CMD_NO_XFER, COMMAND);
+ } else {
+ for_each_sg(sgl, sg, sg_len, i) {
+ if (sg->length > MAX_XFER_BYTES) {
+ dev_err(mxs_dma->dma_device.dev, "maximum bytes for sg entry exceeded: %d > %d\n",
+ sg->length, MAX_XFER_BYTES);
+ goto err_out;
+ }
+
+ ccw = &mxs_chan->ccw[idx++];
+
+ ccw->next = mxs_chan->ccw_phys + sizeof(*ccw) * idx;
+ ccw->bufaddr = sg->dma_address;
+ ccw->xfer_bytes = sg->length;
+
+ ccw->bits = 0;
+ ccw->bits |= CCW_CHAIN;
+ ccw->bits |= CCW_HALT_ON_TERM;
+ ccw->bits |= CCW_TERM_FLUSH;
+ ccw->bits |= BF_CCW(direction == DMA_FROM_DEVICE ?
+ MXS_DMA_CMD_WRITE : MXS_DMA_CMD_READ,
+ COMMAND);
+
+ if (i + 1 == sg_len) {
+ ccw->bits &= ~CCW_CHAIN;
+ ccw->bits |= CCW_IRQ;
+ ccw->bits |= CCW_DEC_SEM;
+ ccw->bits |= CCW_WAIT4END;
+ }
+ }
+ }
+
+ return &mxs_chan->desc;
+
+err_out:
+ mxs_chan->status = DMA_ERROR;
+ return NULL;
+}
+
+static struct dma_async_tx_descriptor *mxs_dma_prep_dma_cyclic(
+ struct dma_chan *chan, dma_addr_t dma_addr, size_t buf_len,
+ size_t period_len, enum dma_data_direction direction)
+{
+ struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
+ struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
+ int num_periods = buf_len / period_len;
+ int i = 0, buf = 0;
+
+ if (mxs_chan->status == DMA_IN_PROGRESS)
+ return NULL;
+
+ mxs_chan->status = DMA_IN_PROGRESS;
+ mxs_chan->flags |= MXS_DMA_SG_LOOP;
+
+ if (num_periods > NUM_CCW) {
+ dev_err(mxs_dma->dma_device.dev,
+ "maximum number of sg exceeded: %d > %d\n",
+ num_periods, NUM_CCW);
+ goto err_out;
+ }
+
+ if (period_len > MAX_XFER_BYTES) {
+ dev_err(mxs_dma->dma_device.dev,
+ "maximum period size exceeded: %d > %d\n",
+ period_len, MAX_XFER_BYTES);
+ goto err_out;
+ }
+
+ while (buf < buf_len) {
+ struct mxs_dma_ccw *ccw = &mxs_chan->ccw[i];
+
+ if (i + 1 == num_periods)
+ ccw->next = mxs_chan->ccw_phys;
+ else
+ ccw->next = mxs_chan->ccw_phys + sizeof(*ccw) * (i + 1);
+
+ ccw->bufaddr = dma_addr;
+ ccw->xfer_bytes = period_len;
+
+ ccw->bits = 0;
+ ccw->bits |= CCW_CHAIN;
+ ccw->bits |= CCW_IRQ;
+ ccw->bits |= CCW_HALT_ON_TERM;
+ ccw->bits |= CCW_TERM_FLUSH;
+ ccw->bits |= BF_CCW(direction == DMA_FROM_DEVICE ?
+ MXS_DMA_CMD_WRITE : MXS_DMA_CMD_READ, COMMAND);
+
+ dma_addr += period_len;
+ buf += period_len;
+
+ i++;
+ }
+
+ return &mxs_chan->desc;
+
+err_out:
+ mxs_chan->status = DMA_ERROR;
+ return NULL;
+}
+
+static int mxs_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
+ unsigned long arg)
+{
+ struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
+ int ret = 0;
+
+ switch (cmd) {
+ case DMA_TERMINATE_ALL:
+ mxs_dma_disable_chan(mxs_chan);
+ break;
+ case DMA_PAUSE:
+ mxs_dma_pause_chan(mxs_chan);
+ break;
+ case DMA_RESUME:
+ mxs_dma_resume_chan(mxs_chan);
+ break;
+ default:
+ ret = -ENOSYS;
+ }
+
+ return ret;
+}
+
+static enum dma_status mxs_dma_tx_status(struct dma_chan *chan,
+ dma_cookie_t cookie, struct dma_tx_state *txstate)
+{
+ struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
+ dma_cookie_t last_used;
+
+ last_used = chan->cookie;
+ dma_set_tx_state(txstate, mxs_chan->last_completed, last_used, 0);
+
+ return mxs_chan->status;
+}
+
+static void mxs_dma_issue_pending(struct dma_chan *chan)
+{
+ /*
+ * Nothing to do. We only have a single descriptor.
+ */
+}
+
+static int __init mxs_dma_init(struct mxs_dma_engine *mxs_dma)
+{
+ int ret;
+
+ ret = clk_enable(mxs_dma->clk);
+ if (ret)
+ goto err_out;
+
+ ret = mxs_reset_block(mxs_dma->base);
+ if (ret)
+ goto err_out;
+
+ /* only major version matters */
+ mxs_dma->version = readl(mxs_dma->base +
+ ((mxs_dma->dev_id == MXS_DMA_APBX) ?
+ HW_APBX_VERSION : HW_APBH_VERSION)) >>
+ BP_APBHX_VERSION_MAJOR;
+
+ /* enable apbh burst */
+ if (dma_is_apbh()) {
+ writel(BM_APBH_CTRL0_APB_BURST_EN,
+ mxs_dma->base + HW_APBHX_CTRL0 + MXS_SET_ADDR);
+ writel(BM_APBH_CTRL0_APB_BURST8_EN,
+ mxs_dma->base + HW_APBHX_CTRL0 + MXS_SET_ADDR);
+ }
+
+ /* enable irq for all the channels */
+ writel(MXS_DMA_CHANNELS_MASK << MXS_DMA_CHANNELS,
+ mxs_dma->base + HW_APBHX_CTRL1 + MXS_SET_ADDR);
+
+ clk_disable(mxs_dma->clk);
+
+ return 0;
+
+err_out:
+ return ret;
+}
+
+static int __init mxs_dma_probe(struct platform_device *pdev)
+{
+ const struct platform_device_id *id_entry =
+ platform_get_device_id(pdev);
+ struct mxs_dma_engine *mxs_dma;
+ struct resource *iores;
+ int ret, i;
+
+ mxs_dma = kzalloc(sizeof(*mxs_dma), GFP_KERNEL);
+ if (!mxs_dma)
+ return -ENOMEM;
+
+ mxs_dma->dev_id = id_entry->driver_data;
+
+ iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+ if (!request_mem_region(iores->start, resource_size(iores),
+ pdev->name)) {
+ ret = -EBUSY;
+ goto err_request_region;
+ }
+
+ mxs_dma->base = ioremap(iores->start, resource_size(iores));
+ if (!mxs_dma->base) {
+ ret = -ENOMEM;
+ goto err_ioremap;
+ }
+
+ mxs_dma->clk = clk_get(&pdev->dev, NULL);
+ if (IS_ERR(mxs_dma->clk)) {
+ ret = PTR_ERR(mxs_dma->clk);
+ goto err_clk;
+ }
+
+ dma_cap_set(DMA_SLAVE, mxs_dma->dma_device.cap_mask);
+ dma_cap_set(DMA_CYCLIC, mxs_dma->dma_device.cap_mask);
+
+ INIT_LIST_HEAD(&mxs_dma->dma_device.channels);
+
+ /* Initialize channel parameters */
+ for (i = 0; i < MXS_DMA_CHANNELS; i++) {
+ struct mxs_dma_chan *mxs_chan = &mxs_dma->mxs_chans[i];
+
+ mxs_chan->mxs_dma = mxs_dma;
+ mxs_chan->chan.device = &mxs_dma->dma_device;
+
+ tasklet_init(&mxs_chan->tasklet, mxs_dma_tasklet,
+ (unsigned long) mxs_chan);
+
+
+ /* Add the channel to mxs_chan list */
+ list_add_tail(&mxs_chan->chan.device_node, &mxs_dma->dma_device.channels);
+ }
+
+ ret = mxs_dma_init(mxs_dma);
+ if (ret)
+ goto err_init;
+
+ mxs_dma->dma_device.dev = &pdev->dev;
+
+ /* mxs_dma gets 65535 bytes maximum sg size */
+ mxs_dma->dma_device.dev->dma_parms = &mxs_dma->dma_parms;
+ dma_set_max_seg_size(mxs_dma->dma_device.dev, MAX_XFER_BYTES);
+
+ mxs_dma->dma_device.device_alloc_chan_resources = mxs_dma_alloc_chan_resources;
+ mxs_dma->dma_device.device_free_chan_resources = mxs_dma_free_chan_resources;
+ mxs_dma->dma_device.device_tx_status = mxs_dma_tx_status;
+ mxs_dma->dma_device.device_prep_slave_sg = mxs_dma_prep_slave_sg;
+ mxs_dma->dma_device.device_prep_dma_cyclic = mxs_dma_prep_dma_cyclic;
+ mxs_dma->dma_device.device_control = mxs_dma_control;
+ mxs_dma->dma_device.device_issue_pending = mxs_dma_issue_pending;
+
+ ret = dma_async_device_register(&mxs_dma->dma_device);
+ if (ret) {
+ dev_err(mxs_dma->dma_device.dev, "unable to register\n");
+ goto err_init;
+ }
+
+ dev_info(mxs_dma->dma_device.dev, "initialized\n");
+
+ return 0;
+
+err_init:
+ clk_put(mxs_dma->clk);
+err_clk:
+ iounmap(mxs_dma->base);
+err_ioremap:
+ release_mem_region(iores->start, resource_size(iores));
+err_request_region:
+ kfree(mxs_dma);
+ return ret;
+}
+
+static struct platform_device_id mxs_dma_type[] = {
+ {
+ .name = "mxs-dma-apbh",
+ .driver_data = MXS_DMA_APBH,
+ }, {
+ .name = "mxs-dma-apbx",
+ .driver_data = MXS_DMA_APBX,
+ }
+};
+
+static struct platform_driver mxs_dma_driver = {
+ .driver = {
+ .name = "mxs-dma",
+ },
+ .id_table = mxs_dma_type,
+};
+
+static int __init mxs_dma_module_init(void)
+{
+ return platform_driver_probe(&mxs_dma_driver, mxs_dma_probe);
+}
+subsys_initcall(mxs_dma_module_init);
--
1.7.1
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