Openwrt/target/linux/ramips/patches-3.9/0148-DMA-MIPS-ralink-add-dmaengine-driver.patch

From 27eef043b05fb8d9d3178fd3352c530f71901dd4 Mon Sep 17 00:00:00 2001
From: John Crispin <blogic@openwrt.org>
Date: Thu, 23 May 2013 18:45:29 +0200
Subject: [PATCH 148/164] DMA: MIPS: ralink: add dmaengine driver

Signed-off-by: John Crispin <blogic@openwrt.org>
---
 drivers/dma/Kconfig       |    7 ++
 drivers/dma/Makefile      |    1 +
 drivers/dma/ralink_gdma.c |  229 +++++++++++++++++++++++++++++++++++++++++++++
 drivers/dma/ralink_gdma.h |   55 +++++++++++
 4 files changed, 292 insertions(+)
 create mode 100644 drivers/dma/ralink_gdma.c
 create mode 100644 drivers/dma/ralink_gdma.h

--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -322,6 +322,13 @@ config MMP_PDMA
 	help
 	  Support the MMP PDMA engine for PXA and MMP platfrom.
 
+config RALINK_GDMA
+	bool "Ralink Generic DMA support"
+	depends on RALINK
+	select DMA_ENGINE
+	help
+	  Support the GDMA engine for MIPS based Ralink SoC.
+
 config DMA_ENGINE
 	bool
 
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -37,3 +37,4 @@ obj-$(CONFIG_DMA_SA11X0) += sa11x0-dma.o
 obj-$(CONFIG_MMP_TDMA) += mmp_tdma.o
 obj-$(CONFIG_DMA_OMAP) += omap-dma.o
 obj-$(CONFIG_MMP_PDMA) += mmp_pdma.o
+obj-$(CONFIG_RALINK_GDMA) += ralink_gdma.o
--- /dev/null
+++ b/drivers/dma/ralink_gdma.c
@@ -0,0 +1,229 @@
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/of_platform.h>
+#include <linux/memory.h>
+
+#include "ralink_gdma.h"
+
+#define SURFBOARDINT_DMA	10
+#define MEMCPY_DMA_CH	8
+#define to_rt2880_dma_chan(chan)            \
+	container_of(chan, struct rt2880_dma_chan, common)
+
+static dma_cookie_t rt2880_dma_tx_submit(struct dma_async_tx_descriptor *tx)
+{
+	dma_cookie_t cookie;
+
+	cookie = tx->chan->cookie;
+
+	return cookie;
+}
+
+#define MIN_RTDMA_PKT_LEN	128
+static struct dma_async_tx_descriptor *
+rt2880_dma_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
+		size_t len, unsigned long flags)
+{
+	struct rt2880_dma_chan *rt_chan = to_rt2880_dma_chan(chan);
+	unsigned long mid_offset;
+
+	spin_lock_bh(&rt_chan->lock);
+
+	if(len < MIN_RTDMA_PKT_LEN) {
+		memcpy(phys_to_virt(dest), phys_to_virt(src), len);
+	} else {
+		mid_offset = len/2;
+
+		/* Lower parts are transferred  by GDMA.
+		 * Upper parts are transferred by CPU.
+		 */
+		RT_DMA_WRITE_REG(RT_DMA_SRC_REG(MEMCPY_DMA_CH), src);
+		RT_DMA_WRITE_REG(RT_DMA_DST_REG(MEMCPY_DMA_CH), dest);
+		RT_DMA_WRITE_REG(RT_DMA_CTRL_REG(MEMCPY_DMA_CH), (mid_offset << 16) | (3 << 3) | (3 << 0));
+
+		memcpy(phys_to_virt(dest)+mid_offset, phys_to_virt(src)+mid_offset, len-mid_offset);
+
+		dma_async_tx_descriptor_init(&rt_chan->txd, chan);
+
+		while((RT_DMA_READ_REG(RT_DMA_DONEINT) & (0x1<<MEMCPY_DMA_CH))==0);
+		RT_DMA_WRITE_REG(RT_DMA_DONEINT, (1<<MEMCPY_DMA_CH));
+	}
+
+	spin_unlock_bh(&rt_chan->lock);
+
+	return &rt_chan->txd;
+}
+
+/**
+ * rt2880_dma_status - poll the status of an XOR transaction
+ * @chan: XOR channel handle
+ * @cookie: XOR transaction identifier
+ * @txstate: XOR transactions state holder (or NULL)
+ */
+static enum dma_status rt2880_dma_status(struct dma_chan *chan,
+					  dma_cookie_t cookie,
+					  struct dma_tx_state *txstate)
+{
+	return 0;
+}
+
+static irqreturn_t rt2880_dma_interrupt_handler(int irq, void *data)
+{
+
+	printk("%s\n",__FUNCTION__);
+
+	return IRQ_HANDLED;
+}
+
+static void rt2880_dma_issue_pending(struct dma_chan *chan)
+{
+}
+
+static int rt2880_dma_alloc_chan_resources(struct dma_chan *chan)
+{
+//	printk("%s\n",__FUNCTION__);
+
+	return 0;
+}
+
+static void rt2880_dma_free_chan_resources(struct dma_chan *chan)
+{
+//	printk("%s\n",__FUNCTION__);
+
+}
+
+static int rt2880_dma_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, unsigned long arg)
+{
+	switch (cmd) {
+	case DMA_TERMINATE_ALL:
+		printk("%s:%s[%d]\n", __FILE__, __func__, __LINE__);
+		break;
+	case DMA_SLAVE_CONFIG:
+		printk("%s:%s[%d]\n", __FILE__, __func__, __LINE__);
+		break;
+	default:
+		return -ENXIO;
+	}
+
+	return 0;
+}
+
+static int rt2880_dma_probe(struct platform_device *pdev)
+{
+	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	__iomem void *membase;
+	struct dma_device *dma_dev;
+	struct rt2880_dma_chan *rt_chan;
+	int err;
+	int ret;
+	int reg;
+	int irq;
+
+	membase = devm_request_and_ioremap(&pdev->dev, res);
+	if (IS_ERR(membase))
+		return PTR_ERR(membase);
+
+	dma_dev = devm_kzalloc(&pdev->dev, sizeof(*dma_dev), GFP_KERNEL);
+	if (!dma_dev)
+		return -ENOMEM;
+
+	irq = platform_get_irq(pdev, 0);
+	if (!irq) {
+		dev_err(&pdev->dev, "failed to load irq\n");
+		return -ENOENT;
+	}
+
+
+	INIT_LIST_HEAD(&dma_dev->channels);
+	dma_cap_zero(dma_dev->cap_mask);
+	dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask);
+	dma_cap_set(DMA_SLAVE, dma_dev->cap_mask);
+	dma_dev->device_alloc_chan_resources = rt2880_dma_alloc_chan_resources;
+	dma_dev->device_free_chan_resources = rt2880_dma_free_chan_resources;
+	dma_dev->device_tx_status = rt2880_dma_status;
+	dma_dev->device_issue_pending = rt2880_dma_issue_pending;
+	dma_dev->device_prep_dma_memcpy = rt2880_dma_prep_dma_memcpy;
+	dma_dev->device_control = rt2880_dma_control;
+	dma_dev->dev = &pdev->dev;
+
+	rt_chan = devm_kzalloc(&pdev->dev, sizeof(*rt_chan), GFP_KERNEL);
+        if (!rt_chan) {
+		return -ENOMEM;
+	}
+
+	spin_lock_init(&rt_chan->lock);
+        INIT_LIST_HEAD(&rt_chan->chain);
+	INIT_LIST_HEAD(&rt_chan->completed_slots);
+	INIT_LIST_HEAD(&rt_chan->all_slots);
+	rt_chan->common.device = dma_dev;
+	rt_chan->txd.tx_submit = rt2880_dma_tx_submit;
+
+	list_add_tail(&rt_chan->common.device_node, &dma_dev->channels);
+
+	err = dma_async_device_register(dma_dev);
+	if (0 != err) {
+		pr_err("ERR_MDMA:device_register failed: %d\n", err);
+		return 1;
+	}
+
+	ret = request_irq(irq, rt2880_dma_interrupt_handler, 0, dev_name(&pdev->dev), NULL);
+	if(ret){
+		pr_err("IRQ %d is not free.\n", SURFBOARDINT_DMA);
+		return 1;
+	}
+
+	//set GDMA register in advance.
+	reg = (32 << 16) | (32 << 8) | (MEMCPY_DMA_CH << 3);
+	RT_DMA_WRITE_REG(RT_DMA_CTRL_REG1(MEMCPY_DMA_CH), reg);
+
+	dev_info(&pdev->dev, "running\n");
+
+	return 0;
+}
+
+static int rt2880_dma_remove(struct platform_device *dev)
+{
+	struct dma_device *dma_dev = platform_get_drvdata(dev);
+
+	printk("%s\n",__FUNCTION__);
+
+	dma_async_device_unregister(dma_dev);
+
+	return 0;
+}
+
+static const struct of_device_id rt2880_dma_match[] = {
+	{ .compatible = "ralink,rt2880-gdma" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, rt2880_wdt_match);
+
+static struct platform_driver rt2880_dma_driver = {
+	.probe		= rt2880_dma_probe,
+	.remove		= rt2880_dma_remove,
+	.driver		= {
+		.owner	= THIS_MODULE,
+		.name	= RT_DMA_NAME,
+		.of_match_table = rt2880_dma_match,
+	},
+};
+
+static int __init rt2880_dma_init(void)
+{
+	int rc;
+
+	rc = platform_driver_register(&rt2880_dma_driver);
+	return rc;
+}
+module_init(rt2880_dma_init);
+
+MODULE_AUTHOR("Steven Liu <steven_liu@mediatek.com>");
+MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
+MODULE_DESCRIPTION("DMA engine driver for Ralink DMA engine");
+MODULE_LICENSE("GPL");
--- /dev/null
+++ b/drivers/dma/ralink_gdma.h
@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2007, 2008, Marvell International Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef RT_DMA_H
+#define RT_DMA_H
+
+#include <linux/types.h>
+#include <linux/io.h>
+#include <linux/dmaengine.h>
+#include <linux/interrupt.h>
+
+#define RT_DMA_NAME		"rt2880_dma"
+
+#define RALINK_GDMA_BASE	0xB0002800
+
+struct rt2880_dma_chan {
+        int                     pending;
+        dma_cookie_t            completed_cookie;
+        spinlock_t              lock; /* protects the descriptor slot pool */
+        void __iomem            *mmr_base;
+        unsigned int            idx;
+        enum dma_transaction_type       current_type;
+	struct dma_async_tx_descriptor txd;
+        struct list_head        chain;
+        struct list_head        completed_slots;
+        struct dma_chan         common;
+        struct list_head        all_slots;
+        int                     slots_allocated;
+        struct tasklet_struct   irq_tasklet;
+};
+
+#define RT_DMA_READ_REG(addr)             le32_to_cpu(*(volatile u32 *)(addr))
+#define RT_DMA_WRITE_REG(addr, val)       *((volatile uint32_t *)(addr)) = cpu_to_le32(val)
+
+#define RT_DMA_SRC_REG(ch)                (RALINK_GDMA_BASE + ch*16)
+#define RT_DMA_DST_REG(ch)                (RT_DMA_SRC_REG(ch) + 4)
+#define RT_DMA_CTRL_REG(ch)               (RT_DMA_DST_REG(ch) + 4)
+#define RT_DMA_CTRL_REG1(ch)              (RT_DMA_CTRL_REG(ch) + 4)
+#define RT_DMA_DONEINT			  (RALINK_GDMA_BASE + 0x204)
+
+#endif