diff options
author | Ingo Molnar <mingo@kernel.org> | 2012-04-13 09:57:10 +0200 |
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committer | Ingo Molnar <mingo@kernel.org> | 2012-04-13 09:57:10 +0200 |
commit | a385ec4f11bdcf81af094c03e2444ee9b7fad2e5 (patch) | |
tree | a2c186cb828e3713c2ec48a4d7191166fb798b3d /arch/arm/mach-tegra/apbio.c | |
parent | 659c36fcda403013a01b85da07cf2d9711e6d6c7 (diff) | |
parent | 0034102808e0dbbf3a2394b82b1bb40b5778de9e (diff) |
Merge tag 'v3.4-rc2' into perf/core
Merge Linux 3.4-rc2: we were on v3.3, update the base.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/arm/mach-tegra/apbio.c')
-rw-r--r-- | arch/arm/mach-tegra/apbio.c | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/arch/arm/mach-tegra/apbio.c b/arch/arm/mach-tegra/apbio.c new file mode 100644 index 00000000000..e75451e517b --- /dev/null +++ b/arch/arm/mach-tegra/apbio.c @@ -0,0 +1,145 @@ +/* + * 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/kernel.h> +#include <linux/io.h> +#include <linux/dma-mapping.h> +#include <linux/spinlock.h> +#include <linux/completion.h> +#include <linux/sched.h> +#include <linux/mutex.h> + +#include <mach/dma.h> +#include <mach/iomap.h> + +#include "apbio.h" + +static DEFINE_MUTEX(tegra_apb_dma_lock); + +static struct tegra_dma_channel *tegra_apb_dma; +static u32 *tegra_apb_bb; +static dma_addr_t tegra_apb_bb_phys; +static DECLARE_COMPLETION(tegra_apb_wait); + +bool tegra_apb_init(void) +{ + struct tegra_dma_channel *ch; + + mutex_lock(&tegra_apb_dma_lock); + + /* Check to see if we raced to setup */ + if (tegra_apb_dma) + goto out; + + ch = tegra_dma_allocate_channel(TEGRA_DMA_MODE_ONESHOT | + TEGRA_DMA_SHARED); + + if (!ch) + goto out_fail; + + 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__); + tegra_dma_free_channel(ch); + goto out_fail; + } + + tegra_apb_dma = ch; +out: + mutex_unlock(&tegra_apb_dma_lock); + return true; + +out_fail: + mutex_unlock(&tegra_apb_dma_lock); + return false; +} + +static void apb_dma_complete(struct tegra_dma_req *req) +{ + complete(&tegra_apb_wait); +} + +u32 tegra_apb_readl(unsigned long offset) +{ + struct tegra_dma_req req; + int ret; + + if (!tegra_apb_dma && !tegra_apb_init()) + return readl(IO_TO_VIRT(offset)); + + mutex_lock(&tegra_apb_dma_lock); + req.complete = apb_dma_complete; + req.to_memory = 1; + req.dest_addr = tegra_apb_bb_phys; + req.dest_bus_width = 32; + req.dest_wrap = 1; + req.source_addr = offset; + req.source_bus_width = 32; + req.source_wrap = 4; + req.req_sel = TEGRA_DMA_REQ_SEL_CNTR; + req.size = 4; + + INIT_COMPLETION(tegra_apb_wait); + + tegra_dma_enqueue_req(tegra_apb_dma, &req); + + ret = wait_for_completion_timeout(&tegra_apb_wait, + msecs_to_jiffies(50)); + + if (WARN(ret == 0, "apb read dma timed out")) { + tegra_dma_dequeue_req(tegra_apb_dma, &req); + *(u32 *)tegra_apb_bb = 0; + } + + mutex_unlock(&tegra_apb_dma_lock); + return *((u32 *)tegra_apb_bb); +} + +void tegra_apb_writel(u32 value, unsigned long offset) +{ + struct tegra_dma_req req; + int ret; + + if (!tegra_apb_dma && !tegra_apb_init()) { + writel(value, IO_TO_VIRT(offset)); + return; + } + + mutex_lock(&tegra_apb_dma_lock); + *((u32 *)tegra_apb_bb) = value; + req.complete = apb_dma_complete; + req.to_memory = 0; + req.dest_addr = offset; + req.dest_wrap = 4; + req.dest_bus_width = 32; + req.source_addr = tegra_apb_bb_phys; + req.source_bus_width = 32; + req.source_wrap = 1; + req.req_sel = TEGRA_DMA_REQ_SEL_CNTR; + req.size = 4; + + INIT_COMPLETION(tegra_apb_wait); + + tegra_dma_enqueue_req(tegra_apb_dma, &req); + + ret = wait_for_completion_timeout(&tegra_apb_wait, + msecs_to_jiffies(50)); + + if (WARN(ret == 0, "apb write dma timed out")) + tegra_dma_dequeue_req(tegra_apb_dma, &req); + + mutex_unlock(&tegra_apb_dma_lock); +} |