From 1db0d19afe5830f7d020c7c5386be8cc20cf0f15 Mon Sep 17 00:00:00 2001
From: John Crispin <blogic@openwrt.org>
Date: Thu, 23 May 2013 18:45:29 +0200
Subject: [PATCH 61/79] 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
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index d4c1218..323f684 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -320,6 +320,13 @@ 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
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index 7428fea..a981e2c 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -34,3 +34,4 @@ 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
diff --git a/drivers/dma/ralink_gdma.c b/drivers/dma/ralink_gdma.c
new file mode 100644
index 0000000..be7c317
--- /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");
diff --git a/drivers/dma/ralink_gdma.h b/drivers/dma/ralink_gdma.h
new file mode 100644
index 0000000..73e1948
--- /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
--
1.7.10.4