[PATCH 3/3] dma: Add Freescale eDMA engine driver support

Jingchang Lu b35083 at freescale.com
Fri Aug 2 03:55:48 EDT 2013


Add Freescale enhanced direct memory(eDMA) controller support.
The eDMA controller deploys DMAMUXs routing DMA request sources(slot)
to eDMA channels.
This module can be found on Vybrid and LS-1 SoCs.

Signed-off-by: Alison Wang <b18965 at freescale.com>
Signed-off-by: Xiaochun Li <b41219 at freescale.com>
Signed-off-by: Jingchang Lu <b35083 at freescale.com>
---
 .../devicetree/bindings/dma/fsl-vf610-edma.txt     |  84 +++
 drivers/dma/Kconfig                                |  10 +
 drivers/dma/Makefile                               |   1 +
 drivers/dma/fsl-edma.c                             | 826 +++++++++++++++++++++
 4 files changed, 921 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/dma/fsl-vf610-edma.txt
 create mode 100644 drivers/dma/fsl-edma.c

diff --git a/Documentation/devicetree/bindings/dma/fsl-vf610-edma.txt b/Documentation/devicetree/bindings/dma/fsl-vf610-edma.txt
new file mode 100644
index 0000000..e6dc5cd
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/fsl-vf610-edma.txt
@@ -0,0 +1,84 @@
+* Freescale enhanced direct memory access(eDMA) Controller
+
+The eDMA engine deploys DMAMUXs routing request sources(slot) to
+eDMA controller channels.
+
+* eDMA Controller
+Required properties:
+- compatible : Should be "fsl,<chip>-edma"
+- reg : Should contain eDMA registers location and length
+- interrupts : Should contain eDMA interrupt
+- interrupt-names : Should be "edma-tx" for tx interrupt and
+  "edma-err" for err interrupt
+- #dma-cells : Must be <2>.
+  The first cell specifies the DMAMUX ID. Specific request source
+  can only be routed by specific DMAMUXs.
+  the second cell specifies the request source(slot) ID.
+  See include/dt-bindings/dma/<soc>-edma.h for all the supported
+  request source IDs.
+- fsl,dma-channels : Number of channels supported by the controller
+- fsl,dma-mux : Phandle of the DMAMUXs deployed by the controller
+
+
+* DMAMUX
+Required properties:
+- reg : Should contain DMAMUX registers location and length
+- fsl,dmamux-id : DMAMUX ID. DMAMUX IDs are unique in each eDMA controller.
+  inside one eDMA controller, specific request source can only be routed by
+  one of its DMAMUXs.
+  However Specific request source may be routed to different eDMA controller,
+  thus all the DMAMUXs sharing a the same request sources have the same ID.
+- clocks : Phandle of the clock used by the DMAMUX
+- clock-names : The clock names
+
+Below is the eDMA controller and DMAMUX association, and DMAMUX IDs assignment
+On Vybrid vf610 SoC, DMAMUX0 and DMAMU3 share the same request source group,
+and DMAMUX1 and DMAMU2 share the same request source group.
+
+eDMA controller		DMAMUXs		DMAMUX ID
+-------------------------------------------------
+eDMA0			DMAMUX0		0
+			DMAMUX1		1
+
+eDMA1			DMAMUX2		1
+			DMAMUX3		0
+
+Examples:
+
+edma0: edma at 40018000 {
+	#dma-cells = <2>;
+	compatible = "fsl,vf610-edma";
+	reg = <0x40018000 0x2000>;
+	interrupts = <0 8 0x04>, <0 9 0x04>;
+	interrupt-names = "edma-tx", "edma-err";
+	fsl,edma-channels = <32>;
+	fsl,edma-mux = <&dmamux0>, <&dmamux1>;
+	};
+
+dmamux0: dmamux at 40024000 {
+	reg = <0x40024000 0x1000>;
+	fsl,dmamux-id = <0>;
+	clocks = <&clks VF610_CLK_DMAMUX0>;
+	clock-names = "dmamux";
+};
+
+
+* DMA clients
+DMA client drivers that uses the DMA function must use the format described
+in the dma.txt file, using a three-cell specifier for each channel: a phandle
+plus two integer cells as described above.
+
+Examples:
+
+sai2: sai at 40031000 {
+	compatible = "fsl,vf610-sai";
+	reg = <0x40031000 0x1000>;
+	interrupts = <0 86 0x04>;
+	clocks = <&clks VF610_CLK_SAI2>;
+	clock-names = "sai";
+	fsl,sai-dma-events = <21 20>;
+	dma-names = "tx", "rx";
+	dmas = <&edma0 0 DMA_MUXID0_SAI2_TX>,
+		<&edma0 0 DMA_MUXID0_SAI2_RX>;
+	status = "disabled";
+};
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 6825957..f9a6e06 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -300,6 +300,16 @@ config DMA_JZ4740
 	select DMA_ENGINE
 	select DMA_VIRTUAL_CHANNELS
 
+config FSL_EDMA
+	tristate "Freescale eDMA engine support"
+	depends on OF
+	select DMA_ENGINE
+	select DMA_VIRTUAL_CHANNELS
+	help
+	  Support the Freescale eDMA engine with DMAMUXs managing route
+	  between request sources(slot) and eDMA engine channels.
+	  This module can be found on Freescale Vybrid and LS-1 SoCs.
+
 config DMA_ENGINE
 	bool
 
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index 5e0f2ef..fcbbac9 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -39,3 +39,4 @@ obj-$(CONFIG_MMP_TDMA) += mmp_tdma.o
 obj-$(CONFIG_DMA_OMAP) += omap-dma.o
 obj-$(CONFIG_MMP_PDMA) += mmp_pdma.o
 obj-$(CONFIG_DMA_JZ4740) += dma-jz4740.o
+obj-$(CONFIG_FSL_EDMA) += fsl-edma.o
diff --git a/drivers/dma/fsl-edma.c b/drivers/dma/fsl-edma.c
new file mode 100644
index 0000000..b3a459f
--- /dev/null
+++ b/drivers/dma/fsl-edma.c
@@ -0,0 +1,826 @@
+/*
+ * drivers/dma/fsl-edma.c
+ *
+ * Copyright 2013 Freescale Semiconductor, Inc.
+ *
+ * Driver for the Freescale eDMA engine with DMAMUXs managing route between
+ * request sources(slot) and eDMA engine channels, this module can be found
+ * on some Vybrid and Layerscape SoCs.
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/clk.h>
+#include <linux/spinlock.h>
+#include <linux/dma-mapping.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_dma.h>
+#include <linux/dmapool.h>
+
+#include "virt-dma.h"
+
+#define EDMA_CR			0x00
+#define EDMA_ES			0x04
+#define EDMA_ERQ		0x0C
+#define EDMA_EEI		0x14
+#define EDMA_SERQ		0x1B
+#define EDMA_CERQ		0x1A
+#define EDMA_SEEI		0x19
+#define EDMA_CEEI		0x18
+#define EDMA_CINT		0x1F
+#define EDMA_CERR		0x1E
+#define EDMA_SSRT		0x1D
+#define EDMA_CDNE		0x1C
+#define EDMA_INTR		0x24
+#define EDMA_ERR		0x2C
+
+#define EDMA_TCD_SADDR(x)	(0x1000 + 32 * (x))
+#define EDMA_TCD_SOFF(x)	(0x1004 + 32 * (x))
+#define EDMA_TCD_ATTR(x)	(0x1006 + 32 * (x))
+#define EDMA_TCD_NBYTES(x)	(0x1008 + 32 * (x))
+#define EDMA_TCD_SLAST(x)	(0x100C + 32 * (x))
+#define EDMA_TCD_DADDR(x)	(0x1010 + 32 * (x))
+#define EDMA_TCD_DOFF(x)	(0x1014 + 32 * (x))
+#define EDMA_TCD_CITER_ELINK(x)	(0x1016 + 32 * (x))
+#define EDMA_TCD_CITER(x)	(0x1016 + 32 * (x))
+#define EDMA_TCD_DLAST_SGA(x)	(0x1018 + 32 * (x))
+#define EDMA_TCD_CSR(x)		(0x101C + 32 * (x))
+#define EDMA_TCD_BITER_ELINK(x)	(0x101E + 32 * (x))
+#define EDMA_TCD_BITER(x)	(0x101E + 32 * (x))
+
+#define EDMA_CR_EDBG		BIT(1)
+#define EDMA_CR_ERCA		BIT(2)
+#define EDMA_CR_ERGA		BIT(3)
+#define EDMA_CR_HOE		BIT(4)
+#define EDMA_CR_HALT		BIT(5)
+#define EDMA_CR_CLM		BIT(6)
+#define EDMA_CR_EMLM		BIT(7)
+#define EDMA_CR_ECX		BIT(16)
+#define EDMA_CR_CX		BIT(17)
+
+#define EDMA_SEEI_SEEI(x)	((x) & 0x1F)
+#define EDMA_CEEI_CEEI(x)	((x) & 0x1F)
+#define EDMA_CINT_CINT(x)	((x) & 0x1F)
+#define EDMA_CERR_CERR(x)	((x) & 0x1F)
+
+#define EDMA_TCD_ATTR_DSIZE(x)		(((x) & 0x0007))
+#define EDMA_TCD_ATTR_DMOD(x)		(((x) & 0x001F) << 3)
+#define EDMA_TCD_ATTR_SSIZE(x)		(((x) & 0x0007) << 8)
+#define EDMA_TCD_ATTR_SMOD(x)		(((x) & 0x001F) << 11)
+#define EDMA_TCD_ATTR_SSIZE_8BIT	(0x0000)
+#define EDMA_TCD_ATTR_SSIZE_16BIT	(0x0100)
+#define EDMA_TCD_ATTR_SSIZE_32BIT	(0x0200)
+#define EDMA_TCD_ATTR_SSIZE_64BIT	(0x0300)
+#define EDMA_TCD_ATTR_SSIZE_32BYTE	(0x0500)
+#define EDMA_TCD_ATTR_DSIZE_8BIT	(0x0000)
+#define EDMA_TCD_ATTR_DSIZE_16BIT	(0x0001)
+#define EDMA_TCD_ATTR_DSIZE_32BIT	(0x0002)
+#define EDMA_TCD_ATTR_DSIZE_64BIT	(0x0003)
+#define EDMA_TCD_ATTR_DSIZE_32BYTE	(0x0005)
+
+#define EDMA_TCD_CITER_MASK		0x7FFF
+#define EDMA_TCD_BITER_MASK		0x7FFF
+
+#define EDMA_TCD_SOFF_SOFF(x)		(x)
+#define EDMA_TCD_NBYTES_NBYTES(x)	(x)
+#define EDMA_TCD_SLAST_SLAST(x)		(x)
+#define EDMA_TCD_DADDR_DADDR(x)		(x)
+#define EDMA_TCD_CITER_CITER(x)		((x) & 0x7FFF)
+#define EDMA_TCD_DOFF_DOFF(x)		(x)
+#define EDMA_TCD_DLAST_SGA_DLAST_SGA(x)	(x)
+#define EDMA_TCD_BITER_BITER(x)		((x) & 0x7FFF)
+
+#define EDMA_TCD_CSR_START		BIT(0)
+#define EDMA_TCD_CSR_INT_MAJOR		BIT(1)
+#define EDMA_TCD_CSR_INT_HALF		BIT(2)
+#define EDMA_TCD_CSR_D_REQ		BIT(3)
+#define EDMA_TCD_CSR_E_SG		BIT(4)
+#define EDMA_TCD_CSR_E_LINK		BIT(5)
+#define EDMA_TCD_CSR_ACTIVE		BIT(6)
+#define EDMA_TCD_CSR_DONE		BIT(7)
+
+#define EDMAMUX_CHCFG_DIS		0x0
+#define EDMAMUX_CHCFG_ENBL		0x80
+#define EDMAMUX_CHCFG_SOURCE(n)		((n) & 0x3F)
+
+struct fsl_edma_hw_tcd {
+	u32	saddr;
+	u16	soff;
+	u16	attr;
+	u32	nbytes;
+	u32	slast;
+	u32	daddr;
+	u16	doff;
+	u16	citer;
+	u32	dlast_sga;
+	u16	csr;
+	u16	biter;
+} __packed;
+
+struct fsl_edma_sw_tcd {
+	dma_addr_t			ptcd;
+	struct fsl_edma_hw_tcd		*vtcd;
+};
+
+struct fsl_edma_slave_config {
+	enum dma_transfer_direction	dir;
+	enum dma_slave_buswidth		addr_width;
+	u32				dev_addr;
+	u32				burst;
+	u32				attr;
+};
+
+struct fsl_edma_dmamux {
+	void __iomem			*membase;
+	struct clk			*clk;
+	u32				mux_id;
+};
+
+struct fsl_edma_chan {
+	struct virt_dma_chan		vchan;
+	enum dma_status			status;
+	struct fsl_edma_engine		*edma;
+	struct fsl_edma_dmamux		*edmamux;
+	struct fsl_edma_desc		*edesc;
+
+	u32				slot_id;
+	struct fsl_edma_slave_config	fsc;
+	struct dma_pool			*tcd_pool;
+};
+
+struct fsl_edma_desc {
+	struct virt_dma_desc		vdesc;
+	struct fsl_edma_chan		*echan;
+	bool				iscyclic;
+	unsigned int			n_tcds;
+	struct fsl_edma_sw_tcd		tcd[];
+};
+
+struct fsl_edma_irq {
+	int	txirq;
+	int	errirq;
+};
+
+struct fsl_edma_engine {
+	struct dma_device	dma_dev;
+	void __iomem		*membase;
+	u32			n_chans;
+	u32			n_muxes;
+	struct fsl_edma_dmamux	*edmamux;
+	struct fsl_edma_irq	edmairq;
+	struct fsl_edma_chan	chans[];
+};
+
+struct fsl_edma_filter_param {
+	int	mux_id;
+	int	slot_id;
+};
+
+static inline struct fsl_edma_chan *to_fsl_edma_chan(struct dma_chan *chan)
+{
+	return container_of(chan, struct fsl_edma_chan, vchan.chan);
+}
+
+static inline struct fsl_edma_desc *to_fsl_edma_desc(struct virt_dma_desc *vd)
+{
+	return container_of(vd, struct fsl_edma_desc, vdesc);
+}
+
+static inline void fsl_edma_enable_request(struct fsl_edma_chan *fsl_chan)
+{
+	void __iomem *addr = fsl_chan->edma->membase;
+	u32 ch = fsl_chan->vchan.chan.chan_id;
+
+	writeb(EDMA_SEEI_SEEI(ch), addr + EDMA_SEEI);
+	writeb(ch, addr + EDMA_SERQ);
+}
+
+static inline void fsl_edma_disable_request(struct fsl_edma_chan *fsl_chan)
+{
+	void __iomem *addr = fsl_chan->edma->membase;
+	u32 ch = fsl_chan->vchan.chan.chan_id;
+
+	writeb(ch, addr + EDMA_CERQ);
+	writeb(EDMA_CEEI_CEEI(ch), addr + EDMA_CEEI);
+}
+
+static
+void fsl_edmamux_config_chan(struct fsl_edma_chan *fsl_chan, unsigned char val)
+{
+	void __iomem *mux_addr = fsl_chan->edmamux->membase;
+	unsigned chans_per_mux, ch;
+
+	chans_per_mux = fsl_chan->edma->n_chans / fsl_chan->edma->n_muxes;
+	ch = fsl_chan->vchan.chan.chan_id % chans_per_mux;
+
+	writeb(val, mux_addr + ch);
+}
+
+static unsigned int fsl_edma_get_tcd_attr(enum dma_slave_buswidth addr_width)
+{
+	switch (addr_width) {
+	case 1:
+		return EDMA_TCD_ATTR_SSIZE_8BIT | EDMA_TCD_ATTR_DSIZE_8BIT;
+	case 2:
+		return EDMA_TCD_ATTR_SSIZE_16BIT | EDMA_TCD_ATTR_DSIZE_16BIT;
+	case 4:
+		return EDMA_TCD_ATTR_SSIZE_32BIT | EDMA_TCD_ATTR_DSIZE_32BIT;
+	case 8:
+		return EDMA_TCD_ATTR_SSIZE_64BIT | EDMA_TCD_ATTR_DSIZE_64BIT;
+	default:
+		return EDMA_TCD_ATTR_SSIZE_32BIT | EDMA_TCD_ATTR_DSIZE_32BIT;
+	}
+}
+
+static void fsl_edma_free_desc(struct virt_dma_desc *vdesc)
+{
+	struct fsl_edma_desc *fsl_desc;
+	int i;
+
+	fsl_desc = to_fsl_edma_desc(vdesc);
+	for (i = 0; i < fsl_desc->n_tcds; i++)
+			dma_pool_free(fsl_desc->echan->tcd_pool,
+					fsl_desc->tcd[i].vtcd,
+					fsl_desc->tcd[i].ptcd);
+	kfree(fsl_desc);
+}
+
+static int fsl_edma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
+		unsigned long arg)
+{
+	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
+	struct dma_slave_config *cfg = (void *)arg;
+
+	switch (cmd) {
+	case DMA_TERMINATE_ALL:
+		fsl_edma_disable_request(fsl_chan);
+		fsl_chan->edesc = NULL;
+		vchan_free_chan_resources(&fsl_chan->vchan);
+		return 0;
+	case DMA_SLAVE_CONFIG:
+		fsl_chan->fsc.dir = cfg->direction;
+		if (cfg->direction == DMA_DEV_TO_MEM) {
+			fsl_chan->fsc.dev_addr = cfg->src_addr;
+			fsl_chan->fsc.addr_width = cfg->src_addr_width;
+			fsl_chan->fsc.burst = cfg->src_maxburst;
+		} else {
+			fsl_chan->fsc.dev_addr = cfg->dst_addr;
+			fsl_chan->fsc.addr_width = cfg->dst_addr_width;
+			fsl_chan->fsc.burst = cfg->dst_maxburst;
+		}
+		fsl_chan->fsc.attr = fsl_edma_get_tcd_attr(fsl_chan->fsc.addr_width);
+		return 0;
+	default:
+		return -ENOSYS;
+	}
+}
+
+static enum dma_status fsl_edma_tx_status(struct dma_chan *chan,
+		dma_cookie_t cookie, struct dma_tx_state *txstate)
+{
+	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
+
+	if (fsl_chan->status == DMA_ERROR)
+		return DMA_ERROR;
+
+	return dma_cookie_status(chan, cookie, txstate);
+}
+
+static void fsl_edma_set_tcd_params(struct fsl_edma_chan *fsl_chan,
+		u32 src, u32 dst, u16 attr, u16 soff, u32 nbytes,
+		u32 slast, u16 citer, u16 biter, u32 doff, u32 dlast_sga,
+		u16 csr)
+{
+	void __iomem *addr = fsl_chan->edma->membase;
+	u32 ch = fsl_chan->vchan.chan.chan_id;
+
+	writew(0, addr + EDMA_TCD_CSR(ch));
+	writel(src, addr + EDMA_TCD_SADDR(ch));
+	writel(dst, addr + EDMA_TCD_DADDR(ch));
+	writew(attr, addr + EDMA_TCD_ATTR(ch));
+	writew(EDMA_TCD_SOFF_SOFF(soff), addr + EDMA_TCD_SOFF(ch));
+	writel(EDMA_TCD_NBYTES_NBYTES(nbytes), addr + EDMA_TCD_NBYTES(ch));
+	writel(EDMA_TCD_SLAST_SLAST(slast), addr + EDMA_TCD_SLAST(ch));
+	writew(EDMA_TCD_CITER_CITER(citer), addr + EDMA_TCD_CITER(ch));
+	writew(EDMA_TCD_BITER_BITER(biter), addr + EDMA_TCD_BITER(ch));
+	writew(EDMA_TCD_DOFF_DOFF(doff), addr + EDMA_TCD_DOFF(ch));
+	writel(EDMA_TCD_DLAST_SGA_DLAST_SGA(dlast_sga),
+					addr + EDMA_TCD_DLAST_SGA(ch));
+	writew(csr, addr + EDMA_TCD_CSR(ch));
+}
+
+static void fill_tcd_params(struct fsl_edma_hw_tcd *tcd, u32 src, u32 dst,
+		u16 attr, u16 soff, u32 nbytes, u32 slast, u16 citer,
+		u16 biter, u16 doff, u32 dlast_sga, bool major_int,
+		bool disable_req, bool enable_sg)
+{
+	tcd->saddr = src;
+	tcd->attr = attr;
+	tcd->soff = soff;
+	tcd->nbytes = nbytes;
+	tcd->slast = slast;
+	tcd->daddr = dst;
+	tcd->citer = citer;
+	tcd->doff = doff;
+	tcd->dlast_sga = dlast_sga;
+	tcd->biter = biter;
+	tcd->csr = 0;
+	if (major_int)
+		tcd->csr |= EDMA_TCD_CSR_INT_MAJOR;
+
+	if (disable_req)
+		tcd->csr |= EDMA_TCD_CSR_D_REQ;
+
+	if (enable_sg)
+		tcd->csr |= EDMA_TCD_CSR_E_SG;
+}
+
+static struct fsl_edma_desc *fsl_edma_alloc_desc(struct fsl_edma_chan *fsl_chan,
+		int sg_len)
+{
+	struct fsl_edma_desc *fsl_desc;
+	int size, i;
+
+	size = sizeof(struct fsl_edma_desc);
+	size += sizeof(struct fsl_edma_sw_tcd) * sg_len;
+	fsl_desc = kzalloc(size, GFP_KERNEL);
+	if (!fsl_desc)
+		return NULL;
+
+	fsl_desc->echan = fsl_chan;
+	fsl_desc->n_tcds = sg_len;
+	for (i = 0; i < sg_len; i++) {
+		fsl_desc->tcd[i].vtcd = dma_pool_alloc(fsl_chan->tcd_pool,
+					GFP_ATOMIC, &fsl_desc->tcd[i].ptcd);
+		if (!fsl_desc->tcd[i].vtcd)
+			goto free_on_err;
+	}
+	return fsl_desc;
+free_on_err:
+	while (--i >= 0)
+		dma_pool_free(fsl_chan->tcd_pool, fsl_desc->tcd[i].vtcd,
+				fsl_desc->tcd[i].ptcd);
+	kfree(fsl_desc);
+	return NULL;
+}
+
+static struct dma_async_tx_descriptor *fsl_edma_prep_dma_cyclic(
+		struct dma_chan *chan, dma_addr_t dma_addr, size_t buf_len,
+		size_t period_len, enum dma_transfer_direction direction,
+		unsigned long flags, void *context)
+{
+	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
+	struct fsl_edma_desc *fsl_desc;
+	dma_addr_t dma_buf_next;
+	int sg_len, i;
+	u32 src_addr, dst_addr, last_sg, nbytes;
+	u16 soff, doff, iter;
+
+	sg_len = buf_len / period_len;
+	fsl_desc = fsl_edma_alloc_desc(fsl_chan, sg_len);
+	if (!fsl_desc)
+		return NULL;
+	fsl_desc->iscyclic = true;
+
+	dma_buf_next = dma_addr;
+	nbytes = fsl_chan->fsc.addr_width * fsl_chan->fsc.burst;
+	iter = period_len / nbytes;
+	for (i = 0; i < sg_len; i++) {
+		if (dma_buf_next >= dma_addr + buf_len)
+			dma_buf_next = dma_addr;
+
+		/* get next sg's physical address */
+		last_sg = fsl_desc->tcd[(i + 1) % sg_len].ptcd;
+
+		if (fsl_chan->fsc.dir == DMA_MEM_TO_DEV) {
+			src_addr = dma_buf_next;
+			dst_addr = fsl_chan->fsc.dev_addr;
+			soff = fsl_chan->fsc.addr_width;
+			doff = 0;
+		} else {
+			src_addr = fsl_chan->fsc.dev_addr;
+			dst_addr = dma_buf_next;
+			soff = 0;
+			doff = fsl_chan->fsc.addr_width;
+		}
+
+		fill_tcd_params(fsl_desc->tcd[i].vtcd, src_addr, dst_addr,
+				fsl_chan->fsc.attr, soff, nbytes, 0,
+				iter, iter, doff, last_sg, true, false, true);
+		dma_buf_next += period_len;
+	}
+
+	return vchan_tx_prep(&fsl_chan->vchan, &fsl_desc->vdesc, flags);
+}
+
+static struct dma_async_tx_descriptor *fsl_edma_prep_slave_sg(
+		struct dma_chan *chan, struct scatterlist *sgl,
+		unsigned int sg_len, enum dma_transfer_direction direction,
+		unsigned long flags, void *context)
+{
+	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
+	struct fsl_edma_desc *fsl_desc;
+	struct scatterlist *sg;
+	u32 src_addr, dst_addr, last_sg, nbytes;
+	u16 soff, doff, iter;
+	int i;
+
+	fsl_desc = fsl_edma_alloc_desc(fsl_chan, sg_len);
+	if (!fsl_desc)
+		return NULL;
+	fsl_desc->iscyclic = false;
+
+	nbytes = fsl_chan->fsc.addr_width * fsl_chan->fsc.burst;
+	for_each_sg(sgl, sg, sg_len, i) {
+		/* get next sg's physical address */
+		last_sg = fsl_desc->tcd[(i + 1) % sg_len].ptcd;
+
+		if (fsl_chan->fsc.dir == DMA_MEM_TO_DEV) {
+			src_addr = sg_dma_address(sg);
+			dst_addr = fsl_chan->fsc.dev_addr;
+			soff = fsl_chan->fsc.addr_width;
+			doff = 0;
+		} else {
+			src_addr = fsl_chan->fsc.dev_addr;
+			dst_addr = sg_dma_address(sg);
+			soff = 0;
+			doff = fsl_chan->fsc.addr_width;
+		}
+
+		iter = sg_dma_len(sg) / nbytes;
+		if (i < sg_len - 1) {
+			last_sg = fsl_desc->tcd[(i + 1)].ptcd;
+			fill_tcd_params(fsl_desc->tcd[i].vtcd, src_addr,
+				dst_addr, fsl_chan->fsc.attr, soff, nbytes, 0,
+				iter, iter, doff, last_sg, false, false, true);
+		} else {
+			last_sg = 0;
+			fill_tcd_params(fsl_desc->tcd[i].vtcd, src_addr,
+				dst_addr, fsl_chan->fsc.attr, soff, nbytes, 0,
+				iter, iter, doff, last_sg, true, true, false);
+		}
+	}
+
+	return vchan_tx_prep(&fsl_chan->vchan, &fsl_desc->vdesc, flags);
+}
+
+static void fsl_edma_xfer_desc(struct fsl_edma_chan *fsl_chan)
+{
+	struct fsl_edma_hw_tcd *tcd;
+	struct virt_dma_desc *vdesc;
+
+	vdesc = vchan_next_desc(&fsl_chan->vchan);
+	if (!vdesc)
+		return;
+	fsl_chan->edesc = to_fsl_edma_desc(vdesc);
+	tcd = fsl_chan->edesc->tcd[0].vtcd;
+	fsl_edma_set_tcd_params(fsl_chan, tcd->saddr, tcd->daddr, tcd->attr,
+			tcd->soff, tcd->nbytes, tcd->slast, tcd->citer,
+			tcd->biter, tcd->doff, tcd->dlast_sga, tcd->csr);
+	fsl_edma_enable_request(fsl_chan);
+	fsl_chan->status = DMA_IN_PROGRESS;
+}
+
+static irqreturn_t fsl_edma_irq_handler(int irq, void *dev_id)
+{
+	struct fsl_edma_engine *fsl_edma = dev_id;
+	unsigned int intr, ch;
+	void __iomem *base_addr;
+	struct fsl_edma_chan *fsl_chan;
+
+	base_addr = fsl_edma->membase;
+
+	intr = readl(base_addr + EDMA_INTR);
+	if (!intr)
+		return IRQ_NONE;
+
+	for (ch = 0; ch < 32; ch++)
+		if (intr & (0x1 << ch))
+			break;
+
+	writeb(EDMA_CINT_CINT(ch), base_addr + EDMA_CINT);
+
+	fsl_chan = &fsl_edma->chans[ch];
+
+	if (!fsl_chan->edesc->iscyclic) {
+		list_del(&fsl_chan->edesc->vdesc.node);
+		vchan_cookie_complete(&fsl_chan->edesc->vdesc);
+		fsl_chan->edesc = NULL;
+		fsl_chan->status = DMA_SUCCESS;
+	} else {
+		vchan_cyclic_callback(&fsl_chan->edesc->vdesc);
+	}
+
+	if (!fsl_chan->edesc)
+		fsl_edma_xfer_desc(fsl_chan);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t fsl_edma_err_handler(int irq, void *dev_id)
+{
+	struct fsl_edma_engine *fsl_edma = dev_id;
+	unsigned long err;
+	int ch;
+
+	err = readl(fsl_edma->membase + EDMA_ERR);
+	if (!err)
+		return IRQ_NONE;
+
+	for (ch = 0; ch < 32; ch++)
+		if (err & (0x1 << ch))
+			break;
+
+	fsl_edma_disable_request(&fsl_edma->chans[ch]);
+	writeb(EDMA_CERR_CERR(ch), fsl_edma->membase + EDMA_CERR);
+	fsl_edma->chans[ch].status = DMA_ERROR;
+
+	return IRQ_HANDLED;
+}
+
+
+static void fsl_edma_issue_pending(struct dma_chan *chan)
+{
+	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
+	unsigned long flags;
+
+	spin_lock_irqsave(&fsl_chan->vchan.lock, flags);
+
+	if (vchan_issue_pending(&fsl_chan->vchan) && !fsl_chan->edesc)
+		fsl_edma_xfer_desc(fsl_chan);
+
+	spin_unlock_irqrestore(&fsl_chan->vchan.lock, flags);
+}
+
+static bool fsl_edma_filter_fn(struct dma_chan *chan, void *fn_param)
+{
+	struct fsl_edma_filter_param *fparam = fn_param;
+	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
+
+	if (fsl_chan->edmamux->mux_id != fparam->mux_id)
+		return false;
+
+	fsl_chan->slot_id = fparam->slot_id;
+	chan->private = fn_param;
+	return true;
+}
+
+static struct dma_chan *fsl_edma_xlate(struct of_phandle_args *dma_spec,
+		struct of_dma *ofdma)
+{
+	dma_cap_mask_t mask;
+	struct fsl_edma_filter_param fparam;
+
+	if (dma_spec->args_count != 2)
+		return NULL;
+
+	fparam.mux_id = dma_spec->args[0];
+	fparam.slot_id = dma_spec->args[1];
+
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_SLAVE, mask);
+	return dma_request_channel(mask, fsl_edma_filter_fn, (void *)&fparam);
+}
+
+static int fsl_edma_alloc_chan_resources(struct dma_chan *chan)
+{
+	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
+	struct fsl_edma_filter_param *data = chan->private;
+	unsigned char val;
+
+	val = EDMAMUX_CHCFG_ENBL | EDMAMUX_CHCFG_SOURCE(data->slot_id);
+	fsl_edmamux_config_chan(fsl_chan, val);
+
+	fsl_chan->tcd_pool = dma_pool_create("tcd_pool", chan->device->dev,
+				sizeof(struct fsl_edma_hw_tcd),
+				32, 0);
+	return 0;
+}
+
+static void fsl_edma_free_chan_resources(struct dma_chan *chan)
+{
+	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
+
+	fsl_edma_disable_request(fsl_chan);
+	fsl_edmamux_config_chan(fsl_chan, EDMAMUX_CHCFG_DIS);
+	fsl_chan->edesc = NULL;
+	vchan_free_chan_resources(&fsl_chan->vchan);
+	dma_pool_destroy(fsl_chan->tcd_pool);
+	fsl_chan->tcd_pool = NULL;
+}
+
+static int
+fsl_init_edmamux(struct platform_device *pdev, struct fsl_edma_engine *fsl_edma)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct fsl_edma_dmamux *fsl_edmamux;
+	struct device_node *phandle;
+	const void *prop;
+	struct resource res;
+	int len, n_muxes, chans_per_mux, ch_off;
+	int i, j;
+	int ret;
+
+	prop = of_get_property(np, "fsl,dma-mux", &len);
+	if (!prop)
+		return -EINVAL;
+
+	n_muxes = len / sizeof(u32);
+	chans_per_mux = fsl_edma->n_chans / n_muxes;
+	fsl_edmamux = devm_kzalloc(&pdev->dev,
+			sizeof(struct fsl_edma_dmamux) * n_muxes, GFP_KERNEL);
+	if (!fsl_edmamux)
+		return -ENOMEM;
+
+	fsl_edma->n_muxes = 0;
+	fsl_edma->edmamux = fsl_edmamux;
+	for (i = 0; i < n_muxes; i++) {
+		phandle = of_parse_phandle(np, "fsl,dma-mux", i);
+		ret = of_address_to_resource(phandle, 0, &res);
+		if (ret)
+			return ret;
+		fsl_edmamux->membase = devm_ioremap_resource(&pdev->dev, &res);
+		if (IS_ERR(fsl_edmamux->membase))
+			return PTR_ERR(fsl_edmamux->membase);
+
+		fsl_edmamux->clk = of_clk_get(phandle, 0);
+		if (IS_ERR(fsl_edmamux->clk))
+			return PTR_ERR(fsl_edmamux->clk);
+
+		clk_prepare_enable(fsl_edmamux->clk);
+
+		ret = of_property_read_u32_index(phandle, "fsl,dmamux-id", 0,
+				&fsl_edmamux->mux_id);
+		if (ret)
+			return ret;
+
+		ch_off = fsl_edma->n_muxes * chans_per_mux;
+		for (j = 0; j < chans_per_mux; j++)
+			fsl_edma->chans[ch_off + j].edmamux = fsl_edmamux;
+
+		fsl_edmamux++;
+		fsl_edma->n_muxes++;
+	}
+	return 0;
+}
+
+static int
+fsl_edma_init_irq(struct platform_device *pdev, struct fsl_edma_engine *fsl_edma)
+{
+	int ret;
+
+	fsl_edma->edmairq.txirq = platform_get_irq_byname(pdev, "edma-tx");
+	if (fsl_edma->edmairq.txirq < 0)
+		return -EINVAL;
+
+	ret = devm_request_irq(&pdev->dev, fsl_edma->edmairq.txirq,
+			fsl_edma_irq_handler, IRQF_SHARED, "eDMA tx", fsl_edma);
+	if (ret) {
+		dev_err(&pdev->dev, "Can't register eDMA tx IRQ.\n");
+		return  ret;
+	}
+
+	fsl_edma->edmairq.errirq = platform_get_irq_byname(pdev, "edma-err");
+	if (fsl_edma->edmairq.errirq < 0)
+		return -EINVAL;
+
+	ret = devm_request_irq(&pdev->dev, fsl_edma->edmairq.errirq,
+			fsl_edma_err_handler, IRQF_SHARED, "eDMA err", fsl_edma);
+	if (ret) {
+		dev_err(&pdev->dev, "Can't register eDMA err IRQ.\n");
+		return  ret;
+	}
+
+	return 0;
+}
+
+static int fsl_edma_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct fsl_edma_engine *fsl_edma;
+	struct fsl_edma_chan *fsl_chan;
+	struct resource *res;
+	int len, chans;
+	int ret, i;
+
+	ret = of_property_read_u32_index(np, "fsl,dma-channels", 0, &chans);
+	if (ret)
+		return -EINVAL;
+
+	len = sizeof(*fsl_edma) + sizeof(*fsl_chan) * chans;
+	fsl_edma = devm_kzalloc(&pdev->dev, len, GFP_KERNEL);
+	if (!fsl_edma)
+		return -ENOMEM;
+
+	fsl_edma->n_chans = chans;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	fsl_edma->membase = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(fsl_edma->membase))
+		return PTR_ERR(fsl_edma->membase);
+
+	ret = fsl_init_edmamux(pdev, fsl_edma);
+	if (ret)
+		return ret;
+
+	ret = fsl_edma_init_irq(pdev, fsl_edma);
+	if (ret)
+		return ret;
+
+	INIT_LIST_HEAD(&fsl_edma->dma_dev.channels);
+	for (i = 0; i < fsl_edma->n_chans; i++) {
+		struct fsl_edma_chan *fsl_chan = &fsl_edma->chans[i];
+
+		fsl_chan->edma = fsl_edma;
+
+		fsl_chan->vchan.desc_free = fsl_edma_free_desc;
+		vchan_init(&fsl_chan->vchan, &fsl_edma->dma_dev);
+
+		writew(0x0, fsl_edma->membase + EDMA_TCD_CSR(i));
+		fsl_edmamux_config_chan(fsl_chan, EDMAMUX_CHCFG_DIS);
+	}
+
+	dma_cap_set(DMA_SLAVE, fsl_edma->dma_dev.cap_mask);
+	dma_cap_set(DMA_CYCLIC, fsl_edma->dma_dev.cap_mask);
+
+	fsl_edma->dma_dev.dev = &pdev->dev;
+	fsl_edma->dma_dev.device_alloc_chan_resources
+		= fsl_edma_alloc_chan_resources;
+	fsl_edma->dma_dev.device_free_chan_resources
+		= fsl_edma_free_chan_resources;
+	fsl_edma->dma_dev.device_tx_status = fsl_edma_tx_status;
+	fsl_edma->dma_dev.device_prep_slave_sg = fsl_edma_prep_slave_sg;
+	fsl_edma->dma_dev.device_prep_dma_cyclic = fsl_edma_prep_dma_cyclic;
+	fsl_edma->dma_dev.device_control = fsl_edma_control;
+	fsl_edma->dma_dev.device_issue_pending = fsl_edma_issue_pending;
+
+	platform_set_drvdata(pdev, fsl_edma);
+
+	ret = dma_async_device_register(&fsl_edma->dma_dev);
+	if (ret) {
+		dev_err(&pdev->dev, "Can't register Freescale eDMA engine.\n");
+		return ret;
+	}
+
+	ret = of_dma_controller_register(np, fsl_edma_xlate, fsl_edma);
+	if (ret) {
+		dev_err(&pdev->dev, "Can't register Freescale eDMA of_dma.\n");
+		dma_async_device_unregister(&fsl_edma->dma_dev);
+		return ret;
+	}
+
+	/* enable round robin arbitration */
+	writel(EDMA_CR_ERGA | EDMA_CR_ERCA, fsl_edma->membase + EDMA_CR);
+
+	return 0;
+}
+
+static int fsl_edma_remove(struct platform_device *pdev)
+{
+	struct fsl_edma_engine *fsl_edma = platform_get_drvdata(pdev);
+	int i;
+
+	dma_async_device_unregister(&fsl_edma->dma_dev);
+
+	for (i = 0; i < fsl_edma->n_muxes; i++) {
+		clk_disable_unprepare(fsl_edma->edmamux[i].clk);
+		clk_put(fsl_edma->edmamux[i].clk);
+	}
+
+	return 0;
+}
+
+static const struct of_device_id fsl_edma_dt_ids[] = {
+	{ .compatible = "fsl,vf610-edma", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, fsl_edma_dt_ids);
+
+static struct platform_driver fsl_edma_driver = {
+	.driver		= {
+		.name	= "fsl-edma",
+		.owner  = THIS_MODULE,
+		.of_match_table = fsl_edma_dt_ids,
+	},
+	.probe          = fsl_edma_probe,
+	.remove		= fsl_edma_remove,
+};
+
+static int __init fsl_edma_module_init(void)
+{
+	return platform_driver_probe(&fsl_edma_driver, fsl_edma_probe);
+}
+module_init(fsl_edma_module_init);
+
+MODULE_DESCRIPTION("Freescale eDMA engine driver");
+MODULE_LICENSE("GPL v2");
-- 
1.8.0





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