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author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-03-28 01:41:24 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-03-28 01:41:24 +0200 |
commit | 34800598b2eebe061445216473b1e4c2ff5cba99 (patch) | |
tree | a6d0eb6fe45d9480888d7ddb34840e172ed80e56 /arch/arm/mach-tegra/apbio.c | |
parent | Merge tag 'rpmsg' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc (diff) | |
parent | Merge tag 'regulator-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/br... (diff) | |
download | linux-34800598b2eebe061445216473b1e4c2ff5cba99.tar.xz linux-34800598b2eebe061445216473b1e4c2ff5cba99.zip |
Merge tag 'drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull "ARM: driver specific updates" from Arnd Bergmann:
"These are all specific to some driver. They are typically the
platform side of a change in the drivers directory, such as adding a
new driver or extending the interface to the platform. In cases where
there is no maintainer for the driver, or the maintainer prefers to
have the platform changes in the same branch as the driver changes,
the patches to the drivers are included as well.
A much smaller set of driver updates that depend on other branches
getting merged first will be sent later.
The new export of tegra_chip_uid conflicts with other changes in
fuse.c. In rtc-sa1100.c, the global removal of IRQF_DISABLED
conflicts with the cleanup of the interrupt handling of that driver.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>"
Fixed up aforementioned trivial conflicts.
* tag 'drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (94 commits)
ARM: SAMSUNG: change the name from s3c-sdhci to exynos4-sdhci
mmc: sdhci-s3c: add platform data for the second capability
ARM: SAMSUNG: support the second capability for samsung-soc
ARM: EXYNOS: add support DMA for EXYNOS4X12 SoC
ARM: EXYNOS: Add apb_pclk clkdev entry for mdma1
ARM: EXYNOS: Enable MDMA driver
regulator: Remove bq24022 regulator driver
rtc: sa1100: add OF support
pxa: magician/hx4700: Convert to gpio-regulator from bq24022
ARM: OMAP3+: SmartReflex: fix error handling
ARM: OMAP3+: SmartReflex: fix the use of debugfs_create_* API
ARM: OMAP3+: SmartReflex: micro-optimization for sanity check
ARM: OMAP3+: SmartReflex: misc cleanups
ARM: OMAP3+: SmartReflex: move late_initcall() closer to its argument
ARM: OMAP3+: SmartReflex: add missing platform_set_drvdata()
ARM: OMAP3+: hwmod: add SmartReflex IRQs
ARM: OMAP3+: SmartReflex: clear ERRCONFIG_VPBOUNDINTST only on a need
ARM: OMAP3+: SmartReflex: Fix status masking in ERRCONFIG register
ARM: OMAP3+: SmartReflex: Add a shutdown hook
ARM: OMAP3+: SmartReflex Class3: disable errorgen before disable VP
...
Conflicts:
arch/arm/mach-tegra/Makefile
arch/arm/mach-tegra/fuse.c
drivers/rtc/rtc-sa1100.c
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 000000000000..e75451e517bd --- /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); +} |