Date:   Tue, 10 Oct 2017 13:23:01 +0800
From:   Baolin Wang <baolin.wang@...eadtrum.com>
To:     <vinod.koul@...el.com>, <robh+dt@...nel.org>,
        <mark.rutland@....com>, <dan.j.williams@...el.com>
CC:     <dmaengine@...r.kernel.org>, <devicetree@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>, <broonie@...nel.org>,
        <baolin.wang@...aro.org>, <baolin.wang@...eadtrum.com>
Subject: [PATCH v4 2/2] dma: sprd: Add Spreadtrum DMA driver

This patch adds the DMA controller driver for Spreadtrum SC9860 platform.

Signed-off-by: Baolin Wang <baolin.wang@...eadtrum.com>
---
Changes since v3:
 - Remove redundant local 'mask' and 'val' variables.
 - Simplify sprd_dma_get_req_type() function.
 - Change pm_runtime_put_sync() to pm_runtime_put() in probe function.
 - Simplify sizeof function.
 - Other coding style fixes.

Changes since v2:
 - Add COMPILE_TEST as dependency.
 - Renamed DMA macro definition properly.
 - Add sprd_dma_chn_update() helpers to save lots of code.
 - Change pm_runtime_put_sync() to pm_runtime_put() when free resources.
 - Re-implement the sprd_dma_tx_status() function.
 - Free irq and kill tasklet when remove driver.
 - Add some documentaion.
 - Change to module_init() level and add MODULE_ALIAS().
 - Other coding style fixes.

Changes since v1:
 - Use virt-dma to manage dma descriptors.
 - Remove link-list and channel-start-channel Spreadtrum special features.
 - Remove device_config implementation.
 - Other optimization.

Note: This patch just implemented the basic DMA_MEMCPY function, and in
future we will send new patches to introduce some Speadtrum special features,
that will be talk about how to handle these features easily instead of in one
big patch which is hard to review.
---
 drivers/dma/Kconfig    |    8 +
 drivers/dma/Makefile   |    1 +
 drivers/dma/sprd-dma.c |  988 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 997 insertions(+)
 create mode 100644 drivers/dma/sprd-dma.c

diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index fadc4d8..a2aa7fe 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -483,6 +483,14 @@ config STM32_DMA
 	  If you have a board based on such a MCU and wish to use DMA say Y
 	  here.
 
+config SPRD_DMA
+	tristate "Spreadtrum DMA support"
+	depends on ARCH_SPRD || COMPILE_TEST
+	select DMA_ENGINE
+	select DMA_VIRTUAL_CHANNELS
+	help
+	  Enable support for the on-chip DMA controller on Spreadtrum platform.
+
 config S3C24XX_DMAC
 	bool "Samsung S3C24XX DMA support"
 	depends on ARCH_S3C24XX || COMPILE_TEST
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index f08f8de..9e7ec34 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -59,6 +59,7 @@ obj-$(CONFIG_RENESAS_DMA) += sh/
 obj-$(CONFIG_SIRF_DMA) += sirf-dma.o
 obj-$(CONFIG_STE_DMA40) += ste_dma40.o ste_dma40_ll.o
 obj-$(CONFIG_STM32_DMA) += stm32-dma.o
+obj-$(CONFIG_SPRD_DMA) += sprd-dma.o
 obj-$(CONFIG_S3C24XX_DMAC) += s3c24xx-dma.o
 obj-$(CONFIG_TXX9_DMAC) += txx9dmac.o
 obj-$(CONFIG_TEGRA20_APB_DMA) += tegra20-apb-dma.o
diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c
new file mode 100644
index 0000000..4d70f7c
--- /dev/null
+++ b/drivers/dma/sprd-dma.c
@@ -0,0 +1,988 @@
+/*
+ * Copyright (C) 2017 Spreadtrum Communications Inc.
+ *
+ * SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+ */
+
+#include <linux/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_dma.h>
+#include <linux/of_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+
+#include "virt-dma.h"
+
+#define SPRD_DMA_CHN_REG_OFFSET		0x1000
+#define SPRD_DMA_CHN_REG_LENGTH		0x40
+#define SPRD_DMA_MEMCPY_MIN_SIZE	64
+
+/* DMA global registers definition */
+#define SPRD_DMA_GLB_PAUSE		0x0
+#define SPRD_DMA_GLB_FRAG_WAIT		0x4
+#define SPRD_DMA_GLB_REQ_PEND0_EN	0x8
+#define SPRD_DMA_GLB_REQ_PEND1_EN	0xc
+#define SPRD_DMA_GLB_INT_RAW_STS	0x10
+#define SPRD_DMA_GLB_INT_MSK_STS	0x14
+#define SPRD_DMA_GLB_REQ_STS		0x18
+#define SPRD_DMA_GLB_CHN_EN_STS		0x1c
+#define SPRD_DMA_GLB_DEBUG_STS		0x20
+#define SPRD_DMA_GLB_ARB_SEL_STS	0x24
+#define SPRD_DMA_GLB_REQ_UID(uid)	(0x4 * ((uid) - 1))
+#define SPRD_DMA_GLB_REQ_UID_OFFSET	0x2000
+
+/* DMA channel registers definition */
+#define SPRD_DMA_CHN_PAUSE		0x0
+#define SPRD_DMA_CHN_REQ		0x4
+#define SPRD_DMA_CHN_CFG		0x8
+#define SPRD_DMA_CHN_INTC		0xc
+#define SPRD_DMA_CHN_SRC_ADDR		0x10
+#define SPRD_DMA_CHN_DES_ADDR		0x14
+#define SPRD_DMA_CHN_FRG_LEN		0x18
+#define SPRD_DMA_CHN_BLK_LEN		0x1c
+#define SPRD_DMA_CHN_TRSC_LEN		0x20
+#define SPRD_DMA_CHN_TRSF_STEP		0x24
+#define SPRD_DMA_CHN_WARP_PTR		0x28
+#define SPRD_DMA_CHN_WARP_TO		0x2c
+#define SPRD_DMA_CHN_LLIST_PTR		0x30
+#define SPRD_DMA_CHN_FRAG_STEP		0x34
+#define SPRD_DMA_CHN_SRC_BLK_STEP	0x38
+#define SPRD_DMA_CHN_DES_BLK_STEP	0x3c
+
+/* SPRD_DMA_CHN_INTC register definition */
+#define SPRD_DMA_INT_MASK		GENMASK(4, 0)
+#define SPRD_DMA_INT_CLR_OFFSET		24
+#define SPRD_DMA_FRAG_INT_EN		BIT(0)
+#define SPRD_DMA_BLK_INT_EN		BIT(1)
+#define SPRD_DMA_TRANS_INT_EN		BIT(2)
+#define SPRD_DMA_LIST_INT_EN		BIT(3)
+#define SPRD_DMA_CFG_ERR_INT_EN		BIT(4)
+
+/* SPRD_DMA_CHN_CFG register definition */
+#define SPRD_DMA_CHN_EN			BIT(0)
+#define SPRD_DMA_WAIT_BDONE		24
+#define SPRD_DMA_DONOT_WAIT_BDONE	1
+
+/* SPRD_DMA_CHN_REQ register definition */
+#define SPRD_DMA_REQ_EN			BIT(0)
+
+/* SPRD_DMA_CHN_PAUSE register definition */
+#define SPRD_DMA_PAUSE_EN		BIT(0)
+#define SPRD_DMA_PAUSE_STS		BIT(2)
+#define SPRD_DMA_PAUSE_CNT		0x2000
+
+/* DMA_CHN_WARP_* register definition */
+#define SPRD_DMA_HIGH_ADDR_MASK		GENMASK(31, 28)
+#define SPRD_DMA_LOW_ADDR_MASK		GENMASK(31, 0)
+#define SPRD_DMA_HIGH_ADDR_OFFSET	4
+
+/* SPRD_DMA_CHN_INTC register definition */
+#define SPRD_DMA_FRAG_INT_STS		BIT(16)
+#define SPRD_DMA_BLK_INT_STS		BIT(17)
+#define SPRD_DMA_TRSC_INT_STS		BIT(18)
+#define SPRD_DMA_LIST_INT_STS		BIT(19)
+#define SPRD_DMA_CFGERR_INT_STS		BIT(20)
+#define SPRD_DMA_CHN_INT_STS					\
+	(SPRD_DMA_FRAG_INT_STS | SPRD_DMA_BLK_INT_STS |		\
+	 SPRD_DMA_TRSC_INT_STS | SPRD_DMA_LIST_INT_STS |	\
+	 SPRD_DMA_CFGERR_INT_STS)
+
+/* SPRD_DMA_CHN_FRG_LEN register definition */
+#define SPRD_DMA_SRC_DATAWIDTH_OFFSET		30
+#define SPRD_DMA_DES_DATAWIDTH_OFFSET		28
+#define SPRD_DMA_SWT_MODE_OFFSET		26
+#define SPRD_DMA_REQ_MODE_OFFSET		24
+#define SPRD_DMA_REQ_MODE_MASK			GENMASK(1, 0)
+#define SPRD_DMA_FIX_SEL_OFFSET			21
+#define SPRD_DMA_FIX_SEL_EN			20
+#define SPRD_DMA_LLIST_END_OFFSET		19
+#define SPRD_DMA_FRG_LEN_MASK			GENMASK(16, 0)
+
+/* SPRD_DMA_CHN_BLK_LEN register definition */
+#define SPRD_DMA_BLK_LEN_MASK			GENMASK(16, 0)
+
+/* SPRD_DMA_CHN_TRSC_LEN register definition */
+#define SPRD_DMA_TRSC_LEN_MASK			GENMASK(27, 0)
+
+/* SPRD_DMA_CHN_TRSF_STEP register definition */
+#define SPRD_DMA_DEST_TRSF_STEP_OFFSET		16
+#define SPRD_DMA_SRC_TRSF_STEP_OFFSET		0
+#define SPRD_DMA_TRSF_STEP_MASK			GENMASK(15, 0)
+
+#define SPRD_DMA_SOFTWARE_UID			0
+
+/*
+ * enum sprd_dma_req_mode: define the DMA request mode
+ * @SPRD_DMA_FRAG_REQ: fragment request mode
+ * @SPRD_DMA_BLK_REQ: block request mode
+ * @SPRD_DMA_TRANS_REQ: transaction request mode
+ * @SPRD_DMA_LIST_REQ: link-list request mode
+ *
+ * We have 4 types request mode: fragment mode, block mode, transaction mode
+ * and linklist mode. One transaction can contain several blocks, one block can
+ * contain several fragments. Link-list mode means we can save several DMA
+ * configuration into one reserved memory, then DMA can fetch each DMA
+ * configuration automatically to start transfer.
+ */
+enum sprd_dma_req_mode {
+	SPRD_DMA_FRAG_REQ,
+	SPRD_DMA_BLK_REQ,
+	SPRD_DMA_TRANS_REQ,
+	SPRD_DMA_LIST_REQ,
+};
+
+/*
+ * enum sprd_dma_int_type: define the DMA interrupt type
+ * @SPRD_DMA_NO_INT: do not need generate DMA interrupts.
+ * @SPRD_DMA_FRAG_INT: fragment done interrupt when one fragment request
+ * is done.
+ * @SPRD_DMA_BLK_INT: block done interrupt when one block request is done.
+ * @SPRD_DMA_BLK_FRAG_INT: block and fragment interrupt when one fragment
+ * or one block request is done.
+ * @SPRD_DMA_TRANS_INT: tansaction done interrupt when one transaction
+ * request is done.
+ * @SPRD_DMA_TRANS_FRAG_INT: transaction and fragment interrupt when one
+ * transaction request or fragment request is done.
+ * @SPRD_DMA_TRANS_BLK_INT: transaction and block interrupt when one
+ * transaction request or block request is done.
+ * @SPRD_DMA_LIST_INT: link-list done interrupt when one link-list request
+ * is done.
+ * @SPRD_DMA_CFGERR_INT: configure error interrupt when configuration is
+ * incorrect.
+ */
+enum sprd_dma_int_type {
+	SPRD_DMA_NO_INT,
+	SPRD_DMA_FRAG_INT,
+	SPRD_DMA_BLK_INT,
+	SPRD_DMA_BLK_FRAG_INT,
+	SPRD_DMA_TRANS_INT,
+	SPRD_DMA_TRANS_FRAG_INT,
+	SPRD_DMA_TRANS_BLK_INT,
+	SPRD_DMA_LIST_INT,
+	SPRD_DMA_CFGERR_INT,
+};
+
+/* dma channel hardware configuration */
+struct sprd_dma_chn_hw {
+	u32 pause;
+	u32 req;
+	u32 cfg;
+	u32 intc;
+	u32 src_addr;
+	u32 des_addr;
+	u32 frg_len;
+	u32 blk_len;
+	u32 trsc_len;
+	u32 trsf_step;
+	u32 wrap_ptr;
+	u32 wrap_to;
+	u32 llist_ptr;
+	u32 frg_step;
+	u32 src_blk_step;
+	u32 des_blk_step;
+};
+
+/* dma request description */
+struct sprd_dma_desc {
+	struct virt_dma_desc	vd;
+	struct sprd_dma_chn_hw	chn_hw;
+};
+
+/* dma channel description */
+struct sprd_dma_chn {
+	struct virt_dma_chan	vc;
+	void __iomem		*chn_base;
+	u32			chn_num;
+	u32			dev_id;
+	struct sprd_dma_desc	*cur_desc;
+};
+
+/* SPRD dma device */
+struct sprd_dma_dev {
+	struct dma_device	dma_dev;
+	void __iomem		*glb_base;
+	struct clk		*clk;
+	struct clk		*ashb_clk;
+	int			irq;
+	u32			total_chns;
+	struct sprd_dma_chn	channels[0];
+};
+
+static bool sprd_dma_filter_fn(struct dma_chan *chan, void *param);
+static struct of_dma_filter_info sprd_dma_info = {
+	.filter_fn = sprd_dma_filter_fn,
+};
+
+static inline struct sprd_dma_chn *to_sprd_dma_chan(struct dma_chan *c)
+{
+	return container_of(c, struct sprd_dma_chn, vc.chan);
+}
+
+static inline struct sprd_dma_dev *to_sprd_dma_dev(struct dma_chan *c)
+{
+	struct sprd_dma_chn *schan = to_sprd_dma_chan(c);
+
+	return container_of(schan, struct sprd_dma_dev, channels[c->chan_id]);
+}
+
+static inline struct sprd_dma_desc *to_sprd_dma_desc(struct virt_dma_desc *vd)
+{
+	return container_of(vd, struct sprd_dma_desc, vd);
+}
+
+static void sprd_dma_chn_update(struct sprd_dma_chn *schan, u32 reg,
+				u32 mask, u32 val)
+{
+	u32 orig = readl(schan->chn_base + reg);
+	u32 tmp;
+
+	tmp = orig & ~mask;
+	tmp |= val & mask;
+
+	writel(tmp, schan->chn_base + reg);
+}
+
+static int sprd_dma_enable(struct sprd_dma_dev *sdev)
+{
+	int ret;
+
+	ret = clk_prepare_enable(sdev->clk);
+	if (ret)
+		return ret;
+
+	/*
+	 * The ashb_clk is optional and only for AGCP DMA controller, so we
+	 * need add one condition to check if the ashb_clk need enable.
+	 */
+	if (!IS_ERR(sdev->ashb_clk))
+		ret = clk_prepare_enable(sdev->ashb_clk);
+
+	return ret;
+}
+
+static void sprd_dma_disable(struct sprd_dma_dev *sdev)
+{
+	clk_disable_unprepare(sdev->clk);
+
+	/*
+	 * Need to check if we need disable the optinal ashb_clk for AGCP DMA.
+	 */
+	if (!IS_ERR(sdev->ashb_clk))
+		clk_disable_unprepare(sdev->ashb_clk);
+}
+
+static void sprd_dma_set_uid(struct sprd_dma_chn *schan)
+{
+	struct sprd_dma_dev *sdev = to_sprd_dma_dev(&schan->vc.chan);
+	u32 dev_id = schan->dev_id;
+
+	if (dev_id != SPRD_DMA_SOFTWARE_UID) {
+		u32 uid_offset = SPRD_DMA_GLB_REQ_UID_OFFSET +
+				 SPRD_DMA_GLB_REQ_UID(dev_id);
+
+		writel(schan->chn_num + 1, sdev->glb_base + uid_offset);
+	}
+}
+
+static void sprd_dma_unset_uid(struct sprd_dma_chn *schan)
+{
+	struct sprd_dma_dev *sdev = to_sprd_dma_dev(&schan->vc.chan);
+	u32 dev_id = schan->dev_id;
+
+	if (dev_id != SPRD_DMA_SOFTWARE_UID) {
+		u32 uid_offset = SPRD_DMA_GLB_REQ_UID_OFFSET +
+				 SPRD_DMA_GLB_REQ_UID(dev_id);
+
+		writel(0, sdev->glb_base + uid_offset);
+	}
+}
+
+static void sprd_dma_clear_int(struct sprd_dma_chn *schan)
+{
+	sprd_dma_chn_update(schan, SPRD_DMA_CHN_INTC,
+			    SPRD_DMA_INT_MASK << SPRD_DMA_INT_CLR_OFFSET,
+			    SPRD_DMA_INT_MASK << SPRD_DMA_INT_CLR_OFFSET);
+}
+
+static void sprd_dma_enable_chn(struct sprd_dma_chn *schan)
+{
+	sprd_dma_chn_update(schan, SPRD_DMA_CHN_CFG, SPRD_DMA_CHN_EN,
+			    SPRD_DMA_CHN_EN);
+}
+
+static void sprd_dma_disable_chn(struct sprd_dma_chn *schan)
+{
+	sprd_dma_chn_update(schan, SPRD_DMA_CHN_CFG, SPRD_DMA_CHN_EN, 0);
+}
+
+static void sprd_dma_soft_request(struct sprd_dma_chn *schan)
+{
+	sprd_dma_chn_update(schan, SPRD_DMA_CHN_REQ, SPRD_DMA_REQ_EN,
+			    SPRD_DMA_REQ_EN);
+}
+
+static void sprd_dma_pause_resume(struct sprd_dma_chn *schan, bool enable)
+{
+	struct sprd_dma_dev *sdev = to_sprd_dma_dev(&schan->vc.chan);
+	u32 pause, timeout = SPRD_DMA_PAUSE_CNT;
+
+	if (enable) {
+		sprd_dma_chn_update(schan, SPRD_DMA_CHN_PAUSE,
+				    SPRD_DMA_PAUSE_EN, SPRD_DMA_PAUSE_EN);
+
+		do {
+			pause = readl(schan->chn_base + SPRD_DMA_CHN_PAUSE);
+			if (pause & SPRD_DMA_PAUSE_STS)
+				break;
+
+			cpu_relax();
+		} while (--timeout > 0);
+
+		if (!timeout)
+			dev_warn(sdev->dma_dev.dev,
+				 "pause dma controller timeout\n");
+	} else {
+		sprd_dma_chn_update(schan, SPRD_DMA_CHN_PAUSE,
+				    SPRD_DMA_PAUSE_EN, 0);
+	}
+}
+
+static void sprd_dma_stop_and_disable(struct sprd_dma_chn *schan)
+{
+	u32 cfg = readl(schan->chn_base + SPRD_DMA_CHN_CFG);
+
+	if (!(cfg & SPRD_DMA_CHN_EN))
+		return;
+
+	sprd_dma_pause_resume(schan, true);
+	sprd_dma_disable_chn(schan);
+}
+
+static unsigned long sprd_dma_get_dst_addr(struct sprd_dma_chn *schan)
+{
+	unsigned long addr, addr_high;
+
+	addr = readl(schan->chn_base + SPRD_DMA_CHN_DES_ADDR);
+	addr_high = readl(schan->chn_base + SPRD_DMA_CHN_WARP_TO) &
+		    SPRD_DMA_HIGH_ADDR_MASK;
+
+	return addr | (addr_high << SPRD_DMA_HIGH_ADDR_OFFSET);
+}
+
+static enum sprd_dma_int_type sprd_dma_get_int_type(struct sprd_dma_chn *schan)
+{
+	u32 intc_sts = readl(schan->chn_base + SPRD_DMA_CHN_INTC) &
+		       SPRD_DMA_CHN_INT_STS;
+
+	switch (intc_sts) {
+	case SPRD_DMA_CFGERR_INT_STS:
+		return SPRD_DMA_CFGERR_INT;
+
+	case SPRD_DMA_LIST_INT_STS:
+		return SPRD_DMA_LIST_INT;
+
+	case SPRD_DMA_TRSC_INT_STS:
+		return SPRD_DMA_TRANS_INT;
+
+	case SPRD_DMA_BLK_INT_STS:
+		return SPRD_DMA_BLK_INT;
+
+	case SPRD_DMA_FRAG_INT_STS:
+		return SPRD_DMA_FRAG_INT;
+
+	default:
+		return SPRD_DMA_NO_INT;
+	}
+}
+
+static enum sprd_dma_req_mode sprd_dma_get_req_type(struct sprd_dma_chn *schan)
+{
+	u32 frag_reg = readl(schan->chn_base + SPRD_DMA_CHN_FRG_LEN);
+
+	return (frag_reg >> SPRD_DMA_REQ_MODE_OFFSET) & SPRD_DMA_REQ_MODE_MASK;
+}
+
+static void sprd_dma_set_chn_config(struct sprd_dma_chn *schan,
+				    struct sprd_dma_desc *sdesc)
+{
+	struct sprd_dma_chn_hw *cfg = &sdesc->chn_hw;
+
+	writel(cfg->pause, schan->chn_base + SPRD_DMA_CHN_PAUSE);
+	writel(cfg->cfg, schan->chn_base + SPRD_DMA_CHN_CFG);
+	writel(cfg->intc, schan->chn_base + SPRD_DMA_CHN_INTC);
+	writel(cfg->src_addr, schan->chn_base + SPRD_DMA_CHN_SRC_ADDR);
+	writel(cfg->des_addr, schan->chn_base + SPRD_DMA_CHN_DES_ADDR);
+	writel(cfg->frg_len, schan->chn_base + SPRD_DMA_CHN_FRG_LEN);
+	writel(cfg->blk_len, schan->chn_base + SPRD_DMA_CHN_BLK_LEN);
+	writel(cfg->trsc_len, schan->chn_base + SPRD_DMA_CHN_TRSC_LEN);
+	writel(cfg->trsf_step, schan->chn_base + SPRD_DMA_CHN_TRSF_STEP);
+	writel(cfg->wrap_ptr, schan->chn_base + SPRD_DMA_CHN_WARP_PTR);
+	writel(cfg->wrap_to, schan->chn_base + SPRD_DMA_CHN_WARP_TO);
+	writel(cfg->llist_ptr, schan->chn_base + SPRD_DMA_CHN_LLIST_PTR);
+	writel(cfg->frg_step, schan->chn_base + SPRD_DMA_CHN_FRAG_STEP);
+	writel(cfg->src_blk_step, schan->chn_base + SPRD_DMA_CHN_SRC_BLK_STEP);
+	writel(cfg->des_blk_step, schan->chn_base + SPRD_DMA_CHN_DES_BLK_STEP);
+	writel(cfg->req, schan->chn_base + SPRD_DMA_CHN_REQ);
+}
+
+static void sprd_dma_start(struct sprd_dma_chn *schan)
+{
+	struct virt_dma_desc *vd = vchan_next_desc(&schan->vc);
+
+	if (!vd)
+		return;
+
+	list_del(&vd->node);
+	schan->cur_desc = to_sprd_dma_desc(vd);
+
+	/*
+	 * Copy the DMA configuration from DMA descriptor to this hardware
+	 * channel.
+	 */
+	sprd_dma_set_chn_config(schan, schan->cur_desc);
+	sprd_dma_set_uid(schan);
+	sprd_dma_enable_chn(schan);
+
+	if (schan->dev_id == SPRD_DMA_SOFTWARE_UID)
+		sprd_dma_soft_request(schan);
+}
+
+static void sprd_dma_stop(struct sprd_dma_chn *schan)
+{
+	sprd_dma_stop_and_disable(schan);
+	sprd_dma_unset_uid(schan);
+	sprd_dma_clear_int(schan);
+}
+
+static bool sprd_dma_check_trans_done(struct sprd_dma_desc *sdesc,
+				      enum sprd_dma_int_type int_type,
+				      enum sprd_dma_req_mode req_mode)
+{
+	if (int_type >= req_mode + 1)
+		return true;
+	else
+		return false;
+}
+
+static irqreturn_t dma_irq_handle(int irq, void *dev_id)
+{
+	struct sprd_dma_dev *sdev = (struct sprd_dma_dev *)dev_id;
+	u32 irq_status = readl(sdev->glb_base + SPRD_DMA_GLB_INT_MSK_STS);
+	struct sprd_dma_chn *schan;
+	struct sprd_dma_desc *sdesc;
+	enum sprd_dma_req_mode req_type;
+	enum sprd_dma_int_type int_type;
+	bool trans_done = false;
+	u32 i;
+
+	while (irq_status) {
+		i = __ffs(irq_status);
+		irq_status &= (irq_status - 1);
+		schan = &sdev->channels[i];
+
+		spin_lock(&schan->vc.lock);
+		int_type = sprd_dma_get_int_type(schan);
+		req_type = sprd_dma_get_req_type(schan);
+		sprd_dma_clear_int(schan);
+
+		sdesc = schan->cur_desc;
+
+		/* Check if the dma request descriptor is done. */
+		trans_done = sprd_dma_check_trans_done(sdesc, int_type,
+						       req_type);
+		if (trans_done == true) {
+			vchan_cookie_complete(&sdesc->vd);
+			schan->cur_desc = NULL;
+			sprd_dma_start(schan);
+		}
+		spin_unlock(&schan->vc.lock);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int sprd_dma_alloc_chan_resources(struct dma_chan *chan)
+{
+	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
+	int ret;
+
+	ret = pm_runtime_get_sync(chan->device->dev);
+	if (ret < 0)
+		return ret;
+
+	schan->dev_id = SPRD_DMA_SOFTWARE_UID;
+	return 0;
+}
+
+static void sprd_dma_free_chan_resources(struct dma_chan *chan)
+{
+	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
+	unsigned long flags;
+
+	spin_lock_irqsave(&schan->vc.lock, flags);
+	sprd_dma_stop(schan);
+	spin_unlock_irqrestore(&schan->vc.lock, flags);
+
+	vchan_free_chan_resources(&schan->vc);
+	pm_runtime_put(chan->device->dev);
+}
+
+static enum dma_status sprd_dma_tx_status(struct dma_chan *chan,
+					  dma_cookie_t cookie,
+					  struct dma_tx_state *txstate)
+{
+	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
+	struct virt_dma_desc *vd;
+	unsigned long flags;
+	enum dma_status ret;
+	u32 pos;
+
+	ret = dma_cookie_status(chan, cookie, txstate);
+
+	spin_lock_irqsave(&schan->vc.lock, flags);
+	vd = vchan_find_desc(&schan->vc, cookie);
+	if (vd) {
+		struct sprd_dma_desc *sdesc = to_sprd_dma_desc(vd);
+		struct sprd_dma_chn_hw *hw = &sdesc->chn_hw;
+
+		if (hw->trsc_len > 0)
+			pos = hw->trsc_len;
+		else if (hw->blk_len > 0)
+			pos = hw->blk_len;
+		else if (hw->frg_len > 0)
+			pos = hw->frg_len;
+		else
+			pos = 0;
+	} else if (schan->cur_desc && schan->cur_desc->vd.tx.cookie == cookie) {
+		pos = sprd_dma_get_dst_addr(schan);
+	} else {
+		pos = 0;
+	}
+	spin_unlock_irqrestore(&schan->vc.lock, flags);
+
+	dma_set_residue(txstate, pos);
+	return ret;
+}
+
+static void sprd_dma_issue_pending(struct dma_chan *chan)
+{
+	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
+	unsigned long flags;
+
+	spin_lock_irqsave(&schan->vc.lock, flags);
+	if (vchan_issue_pending(&schan->vc) && !schan->cur_desc)
+		sprd_dma_start(schan);
+	spin_unlock_irqrestore(&schan->vc.lock, flags);
+}
+
+static int sprd_dma_config(struct dma_chan *chan, struct sprd_dma_desc *sdesc,
+			   dma_addr_t dest, dma_addr_t src, size_t len)
+{
+	struct sprd_dma_dev *sdev = to_sprd_dma_dev(chan);
+	struct sprd_dma_chn_hw *hw = &sdesc->chn_hw;
+	u32 datawidth, src_step, des_step, fragment_len;
+	u32 block_len, req_mode, irq_mode, transcation_len;
+	u32 fix_mode = 0, fix_en = 0;
+
+	if (IS_ALIGNED(len, 4)) {
+		datawidth = 2;
+		src_step = 4;
+		des_step = 4;
+	} else if (IS_ALIGNED(len, 2)) {
+		datawidth = 1;
+		src_step = 2;
+		des_step = 2;
+	} else {
+		datawidth = 0;
+		src_step = 1;
+		des_step = 1;
+	}
+
+	fragment_len = SPRD_DMA_MEMCPY_MIN_SIZE;
+	if (len <= SPRD_DMA_BLK_LEN_MASK) {
+		block_len = len;
+		transcation_len = 0;
+		req_mode = SPRD_DMA_BLK_REQ;
+		irq_mode = SPRD_DMA_BLK_INT;
+	} else {
+		block_len = SPRD_DMA_MEMCPY_MIN_SIZE;
+		transcation_len = len;
+		req_mode = SPRD_DMA_TRANS_REQ;
+		irq_mode = SPRD_DMA_TRANS_INT;
+	}
+
+	hw->cfg = SPRD_DMA_DONOT_WAIT_BDONE << SPRD_DMA_WAIT_BDONE;
+	hw->wrap_ptr = (u32)((src >> SPRD_DMA_HIGH_ADDR_OFFSET) &
+			     SPRD_DMA_HIGH_ADDR_MASK);
+	hw->wrap_to = (u32)((dest >> SPRD_DMA_HIGH_ADDR_OFFSET) &
+			    SPRD_DMA_HIGH_ADDR_MASK);
+
+	hw->src_addr = (u32)(src & SPRD_DMA_LOW_ADDR_MASK);
+	hw->des_addr = (u32)(dest & SPRD_DMA_LOW_ADDR_MASK);
+
+	if ((src_step != 0 && des_step != 0) || (src_step | des_step) == 0) {
+		fix_en = 0;
+	} else {
+		fix_en = 1;
+		if (src_step)
+			fix_mode = 1;
+		else
+			fix_mode = 0;
+	}
+
+	hw->frg_len = datawidth << SPRD_DMA_SRC_DATAWIDTH_OFFSET |
+		datawidth << SPRD_DMA_DES_DATAWIDTH_OFFSET |
+		req_mode << SPRD_DMA_REQ_MODE_OFFSET |
+		fix_mode << SPRD_DMA_FIX_SEL_OFFSET |
+		fix_en << SPRD_DMA_FIX_SEL_EN |
+		(fragment_len & SPRD_DMA_FRG_LEN_MASK);
+	hw->blk_len = block_len & SPRD_DMA_BLK_LEN_MASK;
+
+	hw->intc = SPRD_DMA_CFG_ERR_INT_EN;
+
+	switch (irq_mode) {
+	case SPRD_DMA_NO_INT:
+		break;
+
+	case SPRD_DMA_FRAG_INT:
+		hw->intc |= SPRD_DMA_FRAG_INT_EN;
+		break;
+
+	case SPRD_DMA_BLK_INT:
+		hw->intc |= SPRD_DMA_BLK_INT_EN;
+		break;
+
+	case SPRD_DMA_BLK_FRAG_INT:
+		hw->intc |= SPRD_DMA_BLK_INT_EN | SPRD_DMA_FRAG_INT_EN;
+		break;
+
+	case SPRD_DMA_TRANS_INT:
+		hw->intc |= SPRD_DMA_TRANS_INT_EN;
+		break;
+
+	case SPRD_DMA_TRANS_FRAG_INT:
+		hw->intc |= SPRD_DMA_TRANS_INT_EN | SPRD_DMA_FRAG_INT_EN;
+		break;
+
+	case SPRD_DMA_TRANS_BLK_INT:
+		hw->intc |= SPRD_DMA_TRANS_INT_EN | SPRD_DMA_BLK_INT_EN;
+		break;
+
+	case SPRD_DMA_LIST_INT:
+		hw->intc |= SPRD_DMA_LIST_INT_EN;
+		break;
+
+	case SPRD_DMA_CFGERR_INT:
+		hw->intc |= SPRD_DMA_CFG_ERR_INT_EN;
+		break;
+
+	default:
+		dev_err(sdev->dma_dev.dev, "invalid irq mode\n");
+		return -EINVAL;
+	}
+
+	if (transcation_len == 0)
+		hw->trsc_len = block_len & SPRD_DMA_TRSC_LEN_MASK;
+	else
+		hw->trsc_len = transcation_len & SPRD_DMA_TRSC_LEN_MASK;
+
+	hw->trsf_step = (des_step & SPRD_DMA_TRSF_STEP_MASK) <<
+			SPRD_DMA_DEST_TRSF_STEP_OFFSET |
+			(src_step & SPRD_DMA_TRSF_STEP_MASK) <<
+			SPRD_DMA_SRC_TRSF_STEP_OFFSET;
+
+	hw->frg_step = 0;
+	hw->src_blk_step = 0;
+	hw->des_blk_step = 0;
+	hw->src_blk_step = 0;
+	return 0;
+}
+
+struct dma_async_tx_descriptor *sprd_dma_prep_dma_memcpy(struct dma_chan *chan,
+							 dma_addr_t dest,
+							 dma_addr_t src,
+							 size_t len,
+							 unsigned long flags)
+{
+	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
+	struct sprd_dma_desc *sdesc;
+	int ret;
+
+	sdesc = kzalloc(sizeof(*sdesc), GFP_NOWAIT);
+	if (!sdesc)
+		return NULL;
+
+	ret = sprd_dma_config(chan, sdesc, dest, src, len);
+	if (ret) {
+		kfree(sdesc);
+		return NULL;
+	}
+
+	return vchan_tx_prep(&schan->vc, &sdesc->vd, flags);
+}
+
+static int sprd_dma_pause(struct dma_chan *chan)
+{
+	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
+	unsigned long flags;
+
+	spin_lock_irqsave(&schan->vc.lock, flags);
+	sprd_dma_pause_resume(schan, true);
+	spin_unlock_irqrestore(&schan->vc.lock, flags);
+
+	return 0;
+}
+
+static int sprd_dma_resume(struct dma_chan *chan)
+{
+	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
+	unsigned long flags;
+
+	spin_lock_irqsave(&schan->vc.lock, flags);
+	sprd_dma_pause_resume(schan, false);
+	spin_unlock_irqrestore(&schan->vc.lock, flags);
+
+	return 0;
+}
+
+static int sprd_dma_terminate_all(struct dma_chan *chan)
+{
+	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
+	unsigned long flags;
+	LIST_HEAD(head);
+
+	spin_lock_irqsave(&schan->vc.lock, flags);
+	sprd_dma_stop(schan);
+
+	vchan_get_all_descriptors(&schan->vc, &head);
+	spin_unlock_irqrestore(&schan->vc.lock, flags);
+
+	vchan_dma_desc_free_list(&schan->vc, &head);
+	return 0;
+}
+
+static void sprd_dma_free_desc(struct virt_dma_desc *vd)
+{
+	struct sprd_dma_desc *sdesc = to_sprd_dma_desc(vd);
+
+	kfree(sdesc);
+}
+
+static bool sprd_dma_filter_fn(struct dma_chan *chan, void *param)
+{
+	struct sprd_dma_chn *schan = to_sprd_dma_chan(chan);
+	struct sprd_dma_dev *sdev = to_sprd_dma_dev(&schan->vc.chan);
+	u32 req = *(u32 *)param;
+
+	if (req < sdev->total_chns)
+		return req == schan->chn_num + 1;
+	else
+		return false;
+}
+
+static int sprd_dma_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct sprd_dma_dev *sdev;
+	struct sprd_dma_chn *dma_chn;
+	struct resource *res;
+	u32 chn_count;
+	int ret, i;
+
+	ret = of_property_read_u32(np, "#dma-channels", &chn_count);
+	if (ret) {
+		dev_err(&pdev->dev, "get dma channels count failed\n");
+		return ret;
+	}
+
+	sdev = devm_kzalloc(&pdev->dev, sizeof(*sdev) +
+			    sizeof(*dma_chn) * chn_count,
+			    GFP_KERNEL);
+	if (!sdev)
+		return -ENOMEM;
+
+	sdev->clk = devm_clk_get(&pdev->dev, "enable");
+	if (IS_ERR(sdev->clk)) {
+		dev_err(&pdev->dev, "get enable clock failed\n");
+		return PTR_ERR(sdev->clk);
+	}
+
+	/* ashb clock is optional for AGCP DMA */
+	sdev->ashb_clk = devm_clk_get(&pdev->dev, "ashb_eb");
+	if (IS_ERR(sdev->ashb_clk))
+		dev_warn(&pdev->dev, "no optional ashb eb clock\n");
+
+	/*
+	 * We have three DMA controllers: AP DMA, AON DMA and AGCP DMA. For AGCP
+	 * DMA controller, it can do not request the irq to save system power
+	 * without resuming system by DMA interrupts. Thus the DMA interrupts
+	 * property should be optional.
+	 */
+	sdev->irq = platform_get_irq(pdev, 0);
+	if (sdev->irq > 0) {
+		ret = devm_request_irq(&pdev->dev, sdev->irq, dma_irq_handle,
+				       0, "sprd_dma", (void *)sdev);
+		if (ret < 0) {
+			dev_err(&pdev->dev, "request dma irq failed\n");
+			return ret;
+		}
+	} else {
+		dev_warn(&pdev->dev, "no interrupts for the dma controller\n");
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	sdev->glb_base = devm_ioremap_nocache(&pdev->dev, res->start,
+					      resource_size(res));
+	if (!sdev->glb_base)
+		return -ENOMEM;
+
+	dma_cap_set(DMA_MEMCPY, sdev->dma_dev.cap_mask);
+	sdev->total_chns = chn_count;
+	sdev->dma_dev.chancnt = chn_count;
+	INIT_LIST_HEAD(&sdev->dma_dev.channels);
+	INIT_LIST_HEAD(&sdev->dma_dev.global_node);
+	sdev->dma_dev.dev = &pdev->dev;
+	sdev->dma_dev.device_alloc_chan_resources = sprd_dma_alloc_chan_resources;
+	sdev->dma_dev.device_free_chan_resources = sprd_dma_free_chan_resources;
+	sdev->dma_dev.device_tx_status = sprd_dma_tx_status;
+	sdev->dma_dev.device_issue_pending = sprd_dma_issue_pending;
+	sdev->dma_dev.device_prep_dma_memcpy = sprd_dma_prep_dma_memcpy;
+	sdev->dma_dev.device_pause = sprd_dma_pause;
+	sdev->dma_dev.device_resume = sprd_dma_resume;
+	sdev->dma_dev.device_terminate_all = sprd_dma_terminate_all;
+
+	for (i = 0; i < chn_count; i++) {
+		dma_chn = &sdev->channels[i];
+		dma_chn->chn_num = i;
+		dma_chn->cur_desc = NULL;
+		/* get each channel's registers base address. */
+		dma_chn->chn_base = (void __iomem *)
+			((unsigned long)sdev->glb_base +
+			 SPRD_DMA_CHN_REG_OFFSET +
+			 SPRD_DMA_CHN_REG_LENGTH * i);
+
+		dma_chn->vc.desc_free = sprd_dma_free_desc;
+		vchan_init(&dma_chn->vc, &sdev->dma_dev);
+	}
+
+	platform_set_drvdata(pdev, sdev);
+	ret = sprd_dma_enable(sdev);
+	if (ret)
+		return ret;
+
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+
+	ret = pm_runtime_get_sync(&pdev->dev);
+	if (ret < 0)
+		goto err_rpm;
+
+	ret = dma_async_device_register(&sdev->dma_dev);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "register dma device failed:%d\n", ret);
+		goto err_register;
+	}
+
+	sprd_dma_info.dma_cap = sdev->dma_dev.cap_mask;
+	ret = of_dma_controller_register(np, of_dma_simple_xlate,
+					 &sprd_dma_info);
+	if (ret)
+		goto err_of_register;
+
+	pm_runtime_put(&pdev->dev);
+	return 0;
+
+err_of_register:
+	dma_async_device_unregister(&sdev->dma_dev);
+err_register:
+	pm_runtime_put_noidle(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+err_rpm:
+	sprd_dma_disable(sdev);
+	return ret;
+}
+
+static int sprd_dma_remove(struct platform_device *pdev)
+{
+	struct sprd_dma_dev *sdev = platform_get_drvdata(pdev);
+	struct sprd_dma_chn *c, *cn;
+	int ret;
+
+	ret = pm_runtime_get_sync(&pdev->dev);
+	if (ret < 0)
+		return ret;
+
+	/* explictly free the irq */
+	if (sdev->irq > 0)
+		devm_free_irq(&pdev->dev, sdev->irq, sdev);
+
+	list_for_each_entry_safe(c, cn, &sdev->dma_dev.channels,
+				 vc.chan.device_node) {
+		list_del(&c->vc.chan.device_node);
+		tasklet_kill(&c->vc.task);
+	}
+
+	of_dma_controller_free(pdev->dev.of_node);
+	dma_async_device_unregister(&sdev->dma_dev);
+	sprd_dma_disable(sdev);
+
+	pm_runtime_put_noidle(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+	return 0;
+}
+
+static const struct of_device_id sprd_dma_match[] = {
+	{ .compatible = "sprd,sc9860-dma", },
+	{},
+};
+
+static int __maybe_unused sprd_dma_runtime_suspend(struct device *dev)
+{
+	struct sprd_dma_dev *sdev = dev_get_drvdata(dev);
+
+	sprd_dma_disable(sdev);
+	return 0;
+}
+
+static int __maybe_unused sprd_dma_runtime_resume(struct device *dev)
+{
+	struct sprd_dma_dev *sdev = dev_get_drvdata(dev);
+	int ret;
+
+	ret = sprd_dma_enable(sdev);
+	if (ret) {
+		dev_err(sdev->dma_dev.dev, "enable dma failed\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct dev_pm_ops sprd_dma_pm_ops = {
+	SET_RUNTIME_PM_OPS(sprd_dma_runtime_suspend,
+			   sprd_dma_runtime_resume,
+			   NULL)
+};
+
+static struct platform_driver sprd_dma_driver = {
+	.probe = sprd_dma_probe,
+	.remove = sprd_dma_remove,
+	.driver = {
+		.name = "sprd-dma",
+		.of_match_table = sprd_dma_match,
+		.pm = &sprd_dma_pm_ops,
+	},
+};
+module_platform_driver(sprd_dma_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("DMA driver for Spreadtrum");
+MODULE_AUTHOR("Baolin Wang <baolin.wang@...eadtrum.com>");
+MODULE_ALIAS("platform:sprd-dma");
-- 
1.7.9.5

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