ARM: 6132/1: PL330: Add common core driver

PL330 is a configurable DMA controller PrimeCell device.
The register map of the device is well defined.
The configuration of a particular implementation can be
read from the six configuration registers CR0-4,Dn.

This patch implements a driver for the specification:-
http://infocenter.arm.com/help/topic/com.arm.doc.ddi0424a/DDI0424A_dmac_pl330_r0p0_trm.pdf

The exported interface should be sufficient to implement
a driver for any DMA API.
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/common/Kconfig

@@ -18,6 +18,9 @@ config ICST525
 config ICST307
 	bool
 
+config PL330
+	bool
+
 config SA1111
 	bool
 	select DMABOUNCE if !ARCH_PXA

arch/arm/common/Makefile

@@ -6,6 +6,7 @@ obj-$(CONFIG_ARM_GIC)		+= gic.o
 obj-$(CONFIG_ARM_VIC)		+= vic.o
 obj-$(CONFIG_ICST525)		+= icst525.o
 obj-$(CONFIG_ICST307)		+= icst307.o
+obj-$(CONFIG_PL330)		+= pl330.o
 obj-$(CONFIG_SA1111)		+= sa1111.o
 obj-$(CONFIG_PCI_HOST_VIA82C505) += via82c505.o
 obj-$(CONFIG_DMABOUNCE)		+= dmabounce.o

arch/arm/include/asm/hardware/pl330.h

+/* linux/include/asm/hardware/pl330.h
+ *
+ * Copyright (C) 2010 Samsung Electronics Co. Ltd.
+ *	Jaswinder Singh <jassi.brar@samsung.com>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef __PL330_CORE_H
+#define __PL330_CORE_H
+
+#define PL330_MAX_CHAN		8
+#define PL330_MAX_IRQS		32
+#define PL330_MAX_PERI		32
+
+enum pl330_srccachectrl {
+	SCCTRL0 = 0, /* Noncacheable and nonbufferable */
+	SCCTRL1, /* Bufferable only */
+	SCCTRL2, /* Cacheable, but do not allocate */
+	SCCTRL3, /* Cacheable and bufferable, but do not allocate */
+	SINVALID1,
+	SINVALID2,
+	SCCTRL6, /* Cacheable write-through, allocate on reads only */
+	SCCTRL7, /* Cacheable write-back, allocate on reads only */
+};
+
+enum pl330_dstcachectrl {
+	DCCTRL0 = 0, /* Noncacheable and nonbufferable */
+	DCCTRL1, /* Bufferable only */
+	DCCTRL2, /* Cacheable, but do not allocate */
+	DCCTRL3, /* Cacheable and bufferable, but do not allocate */
+	DINVALID1 = 8,
+	DINVALID2,
+	DCCTRL6, /* Cacheable write-through, allocate on writes only */
+	DCCTRL7, /* Cacheable write-back, allocate on writes only */
+};
+
+/* Populated by the PL330 core driver for DMA API driver's info */
+struct pl330_config {
+	u32	periph_id;
+	u32	pcell_id;
+#define DMAC_MODE_NS	(1 << 0)
+	unsigned int	mode;
+	unsigned int	data_bus_width:10; /* In number of bits */
+	unsigned int	data_buf_dep:10;
+	unsigned int	num_chan:4;
+	unsigned int	num_peri:6;
+	u32		peri_ns;
+	unsigned int	num_events:6;
+	u32		irq_ns;
+};
+
+/* Handle to the DMAC provided to the PL330 core */
+struct pl330_info {
+	/* Owning device */
+	struct device *dev;
+	/* Size of MicroCode buffers for each channel. */
+	unsigned mcbufsz;
+	/* ioremap'ed address of PL330 registers. */
+	void __iomem	*base;
+	/* Client can freely use it. */
+	void	*client_data;
+	/* PL330 core data, Client must not touch it. */
+	void	*pl330_data;
+	/* Populated by the PL330 core driver during pl330_add */
+	struct pl330_config	pcfg;
+	/*
+	 * If the DMAC has some reset mechanism, then the
+	 * client may want to provide pointer to the method.
+	 */
+	void (*dmac_reset)(struct pl330_info *pi);
+};
+
+enum pl330_byteswap {
+	SWAP_NO = 0,
+	SWAP_2,
+	SWAP_4,
+	SWAP_8,
+	SWAP_16,
+};
+
+/**
+ * Request Configuration.
+ * The PL330 core does not modify this and uses the last
+ * working configuration if the request doesn't provide any.
+ *
+ * The Client may want to provide this info only for the
+ * first request and a request with new settings.
+ */
+struct pl330_reqcfg {
+	/* Address Incrementing */
+	unsigned dst_inc:1;
+	unsigned src_inc:1;
+
+	/*
+	 * For now, the SRC & DST protection levels
+	 * and burst size/length are assumed same.
+	 */
+	bool nonsecure;
+	bool privileged;
+	bool insnaccess;
+	unsigned brst_len:5;
+	unsigned brst_size:3; /* in power of 2 */
+
+	enum pl330_dstcachectrl dcctl;
+	enum pl330_srccachectrl scctl;
+	enum pl330_byteswap swap;
+};
+
+/*
+ * One cycle of DMAC operation.
+ * There may be more than one xfer in a request.
+ */
+struct pl330_xfer {
+	u32 src_addr;
+	u32 dst_addr;
+	/* Size to xfer */
+	u32 bytes;
+	/*
+	 * Pointer to next xfer in the list.
+	 * The last xfer in the req must point to NULL.
+	 */
+	struct pl330_xfer *next;
+};
+
+/* The xfer callbacks are made with one of these arguments. */
+enum pl330_op_err {
+	/* The all xfers in the request were success. */
+	PL330_ERR_NONE,
+	/* If req aborted due to global error. */
+	PL330_ERR_ABORT,
+	/* If req failed due to problem with Channel. */
+	PL330_ERR_FAIL,
+};
+
+enum pl330_reqtype {
+	MEMTOMEM,
+	MEMTODEV,
+	DEVTOMEM,
+	DEVTODEV,
+};
+
+/* A request defining Scatter-Gather List ending with NULL xfer. */
+struct pl330_req {
+	enum pl330_reqtype rqtype;
+	/* Index of peripheral for the xfer. */
+	unsigned peri:5;
+	/* Unique token for this xfer, set by the client. */
+	void *token;
+	/* Callback to be called after xfer. */
+	void (*xfer_cb)(void *token, enum pl330_op_err err);
+	/* If NULL, req will be done at last set parameters. */
+	struct pl330_reqcfg *cfg;
+	/* Pointer to first xfer in the request. */
+	struct pl330_xfer *x;
+};
+
+/*
+ * To know the status of the channel and DMAC, the client
+ * provides a pointer to this structure. The PL330 core
+ * fills it with current information.
+ */
+struct pl330_chanstatus {
+	/*
+	 * If the DMAC engine halted due to some error,
+	 * the client should remove-add DMAC.
+	 */
+	bool dmac_halted;
+	/*
+	 * If channel is halted due to some error,
+	 * the client should ABORT/FLUSH and START the channel.
+	 */
+	bool faulting;
+	/* Location of last load */
+	u32 src_addr;
+	/* Location of last store */
+	u32 dst_addr;
+	/*
+	 * Pointer to the currently active req, NULL if channel is
+	 * inactive, even though the requests may be present.
+	 */
+	struct pl330_req *top_req;
+	/* Pointer to req waiting second in the queue if any. */
+	struct pl330_req *wait_req;
+};
+
+enum pl330_chan_op {
+	/* Start the channel */
+	PL330_OP_START,
+	/* Abort the active xfer */
+	PL330_OP_ABORT,
+	/* Stop xfer and flush queue */
+	PL330_OP_FLUSH,
+};
+
+extern int pl330_add(struct pl330_info *);
+extern void pl330_del(struct pl330_info *pi);
+extern int pl330_update(const struct pl330_info *pi);
+extern void pl330_release_channel(void *ch_id);
+extern void *pl330_request_channel(const struct pl330_info *pi);
+extern int pl330_chan_status(void *ch_id, struct pl330_chanstatus *pstatus);
+extern int pl330_chan_ctrl(void *ch_id, enum pl330_chan_op op);
+extern int pl330_submit_req(void *ch_id, struct pl330_req *r);
+
+#endif	/* __PL330_CORE_H */