+++ /dev/null
-/*
- * Copyright (C) 2010 NVIDIA Corporation.
- * Copyright (C) 2010 Google, Inc.
- *
- * This software is licensed under the terms of the GNU General Public
- * License version 2, as published by the Free Software Foundation, and
- * may be copied, distributed, and modified under those terms.
- *
- * 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.
- *
- */
-
-#include <linux/completion.h>
-#include <linux/dmaengine.h>
-#include <linux/dma-mapping.h>
-#include <linux/io.h>
-#include <linux/kernel.h>
-#include <linux/mutex.h>
-#include <linux/of.h>
-#include <linux/sched.h>
-#include <linux/spinlock.h>
-
-#include "apbio.h"
-#include "iomap.h"
-
-#if defined(CONFIG_TEGRA20_APB_DMA)
-static DEFINE_MUTEX(tegra_apb_dma_lock);
-static u32 *tegra_apb_bb;
-static dma_addr_t tegra_apb_bb_phys;
-static DECLARE_COMPLETION(tegra_apb_wait);
-
-static int tegra_apb_readl_direct(unsigned long offset, u32 *value);
-static int tegra_apb_writel_direct(u32 value, unsigned long offset);
-
-static struct dma_chan *tegra_apb_dma_chan;
-static struct dma_slave_config dma_sconfig;
-
-static bool tegra_apb_dma_init(void)
-{
- dma_cap_mask_t mask;
-
- mutex_lock(&tegra_apb_dma_lock);
-
- /* Check to see if we raced to setup */
- if (tegra_apb_dma_chan)
- goto skip_init;
-
- dma_cap_zero(mask);
- dma_cap_set(DMA_SLAVE, mask);
- tegra_apb_dma_chan = dma_request_channel(mask, NULL, NULL);
- if (!tegra_apb_dma_chan) {
- /*
- * This is common until the device is probed, so don't
- * shout about it.
- */
- pr_debug("%s: can not allocate dma channel\n", __func__);
- goto err_dma_alloc;
- }
-
- tegra_apb_bb = dma_alloc_coherent(NULL, sizeof(u32),
- &tegra_apb_bb_phys, GFP_KERNEL);
- if (!tegra_apb_bb) {
- pr_err("%s: can not allocate bounce buffer\n", __func__);
- goto err_buff_alloc;
- }
-
- dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
- dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
- dma_sconfig.src_maxburst = 1;
- dma_sconfig.dst_maxburst = 1;
-
-skip_init:
- mutex_unlock(&tegra_apb_dma_lock);
- return true;
-
-err_buff_alloc:
- dma_release_channel(tegra_apb_dma_chan);
- tegra_apb_dma_chan = NULL;
-
-err_dma_alloc:
- mutex_unlock(&tegra_apb_dma_lock);
- return false;
-}
-
-static void apb_dma_complete(void *args)
-{
- complete(&tegra_apb_wait);
-}
-
-static int do_dma_transfer(unsigned long apb_add,
- enum dma_transfer_direction dir)
-{
- struct dma_async_tx_descriptor *dma_desc;
- int ret;
-
- if (dir == DMA_DEV_TO_MEM)
- dma_sconfig.src_addr = apb_add;
- else
- dma_sconfig.dst_addr = apb_add;
-
- ret = dmaengine_slave_config(tegra_apb_dma_chan, &dma_sconfig);
- if (ret)
- return ret;
-
- dma_desc = dmaengine_prep_slave_single(tegra_apb_dma_chan,
- tegra_apb_bb_phys, sizeof(u32), dir,
- DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
- if (!dma_desc)
- return -EINVAL;
-
- dma_desc->callback = apb_dma_complete;
- dma_desc->callback_param = NULL;
-
- reinit_completion(&tegra_apb_wait);
-
- dmaengine_submit(dma_desc);
- dma_async_issue_pending(tegra_apb_dma_chan);
- ret = wait_for_completion_timeout(&tegra_apb_wait,
- msecs_to_jiffies(50));
-
- if (WARN(ret == 0, "apb read dma timed out")) {
- dmaengine_terminate_all(tegra_apb_dma_chan);
- return -EFAULT;
- }
- return 0;
-}
-
-int tegra_apb_readl_using_dma(unsigned long offset, u32 *value)
-{
- int ret;
-
- if (!tegra_apb_dma_chan && !tegra_apb_dma_init())
- return tegra_apb_readl_direct(offset, value);
-
- mutex_lock(&tegra_apb_dma_lock);
- ret = do_dma_transfer(offset, DMA_DEV_TO_MEM);
- if (ret < 0)
- pr_err("error in reading offset 0x%08lx using dma\n", offset);
- else
- *value = *tegra_apb_bb;
-
- mutex_unlock(&tegra_apb_dma_lock);
-
- return ret;
-}
-
-int tegra_apb_writel_using_dma(u32 value, unsigned long offset)
-{
- int ret;
-
- if (!tegra_apb_dma_chan && !tegra_apb_dma_init())
- return tegra_apb_writel_direct(value, offset);
-
- mutex_lock(&tegra_apb_dma_lock);
- *((u32 *)tegra_apb_bb) = value;
- ret = do_dma_transfer(offset, DMA_MEM_TO_DEV);
- mutex_unlock(&tegra_apb_dma_lock);
- if (ret < 0)
- pr_err("error in writing offset 0x%08lx using dma\n", offset);
-
- return ret;
-}
-#else
-#define tegra_apb_readl_using_dma tegra_apb_readl_direct
-#define tegra_apb_writel_using_dma tegra_apb_writel_direct
-#endif
-
-typedef int (*apbio_read_fptr)(unsigned long offset, u32 *value);
-typedef int (*apbio_write_fptr)(u32 value, unsigned long offset);
-
-static apbio_read_fptr apbio_read;
-static apbio_write_fptr apbio_write;
-
-static int tegra_apb_readl_direct(unsigned long offset, u32 *value)
-{
- *value = readl(IO_ADDRESS(offset));
-
- return 0;
-}
-
-static int tegra_apb_writel_direct(u32 value, unsigned long offset)
-{
- writel(value, IO_ADDRESS(offset));
-
- return 0;
-}
-
-void tegra_apb_io_init(void)
-{
- /* Need to use dma only when it is Tegra20 based platform */
- if (of_machine_is_compatible("nvidia,tegra20") ||
- !of_have_populated_dt()) {
- apbio_read = tegra_apb_readl_using_dma;
- apbio_write = tegra_apb_writel_using_dma;
- } else {
- apbio_read = tegra_apb_readl_direct;
- apbio_write = tegra_apb_writel_direct;
- }
-}
-
-u32 tegra_apb_readl(unsigned long offset)
-{
- u32 val;
-
- if (apbio_read(offset, &val) < 0)
- return 0;
- else
- return val;
-}
-
-void tegra_apb_writel(u32 value, unsigned long offset)
-{
- apbio_write(value, offset);
-}
projects / hercules2020 / nv-tegra / linux-4.4.git / commitdiff