From 0d827a4343b596b71a1741328c4e5687ce654e19 Mon Sep 17 00:00:00 2001 From: Peter De Schrijver Date: Thu, 12 Jun 2014 18:36:40 +0300 Subject: soc/tegra: fuse: move APB DMA into Tegra20 fuse driver The Tegra20 fuse driver is the only user of tegra_apb_readl_using_dma(). Therefore we can simply the code by incorporating the APB DMA handling into the driver directly. tegra_apb_writel_using_dma() is dropped because there are no users. Signed-off-by: Peter De Schrijver Signed-off-by: Stephen Warren Signed-off-by: Thierry Reding --- drivers/soc/tegra/fuse/fuse-tegra20.c | 79 +++++++++++++++++++++++++++++++++-- 1 file changed, 76 insertions(+), 3 deletions(-) (limited to 'drivers/soc/tegra/fuse') diff --git a/drivers/soc/tegra/fuse/fuse-tegra20.c b/drivers/soc/tegra/fuse/fuse-tegra20.c index 7a9d0e045490..7cb63ab6aac2 100644 --- a/drivers/soc/tegra/fuse/fuse-tegra20.c +++ b/drivers/soc/tegra/fuse/fuse-tegra20.c @@ -18,6 +18,9 @@ #include #include +#include +#include +#include #include #include #include @@ -39,18 +42,58 @@ static phys_addr_t fuse_phys; static struct clk *fuse_clk; static void __iomem __initdata *fuse_base; +static DEFINE_MUTEX(apb_dma_lock); +static DECLARE_COMPLETION(apb_dma_wait); +static struct dma_chan *apb_dma_chan; +static struct dma_slave_config dma_sconfig; +static u32 *apb_buffer; +static dma_addr_t apb_buffer_phys; + +static void apb_dma_complete(void *args) +{ + complete(&apb_dma_wait); +} + static u32 tegra20_fuse_readl(const unsigned int offset) { int ret; - u32 val; + u32 val = 0; + struct dma_async_tx_descriptor *dma_desc; + + mutex_lock(&apb_dma_lock); + + dma_sconfig.src_addr = fuse_phys + FUSE_BEGIN + offset; + ret = dmaengine_slave_config(apb_dma_chan, &dma_sconfig); + if (ret) + goto out; + + dma_desc = dmaengine_prep_slave_single(apb_dma_chan, apb_buffer_phys, + sizeof(u32), DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!dma_desc) + goto out; + + dma_desc->callback = apb_dma_complete; + dma_desc->callback_param = NULL; + + reinit_completion(&apb_dma_wait); clk_prepare_enable(fuse_clk); - ret = tegra_apb_readl_using_dma(fuse_phys + FUSE_BEGIN + offset, &val); + dmaengine_submit(dma_desc); + dma_async_issue_pending(apb_dma_chan); + ret = wait_for_completion_timeout(&apb_dma_wait, msecs_to_jiffies(50)); + + if (WARN(ret == 0, "apb read dma timed out")) + dmaengine_terminate_all(apb_dma_chan); + else + val = *apb_buffer; clk_disable_unprepare(fuse_clk); +out: + mutex_unlock(&apb_dma_lock); - return (ret < 0) ? 0 : val; + return val; } static const struct of_device_id tegra20_fuse_of_match[] = { @@ -58,9 +101,35 @@ static const struct of_device_id tegra20_fuse_of_match[] = { {}, }; +static int apb_dma_init(void) +{ + dma_cap_mask_t mask; + + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + apb_dma_chan = dma_request_channel(mask, NULL, NULL); + if (!apb_dma_chan) + return -EPROBE_DEFER; + + apb_buffer = dma_alloc_coherent(NULL, sizeof(u32), &apb_buffer_phys, + GFP_KERNEL); + if (!apb_buffer) { + dma_release_channel(apb_dma_chan); + return -ENOMEM; + } + + 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; + + return 0; +} + static int tegra20_fuse_probe(struct platform_device *pdev) { struct resource *res; + int err; fuse_clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(fuse_clk)) { @@ -73,6 +142,10 @@ static int tegra20_fuse_probe(struct platform_device *pdev) return -EINVAL; fuse_phys = res->start; + err = apb_dma_init(); + if (err) + return err; + if (tegra_fuse_create_sysfs(&pdev->dev, FUSE_SIZE, tegra20_fuse_readl)) return -ENODEV; -- cgit v1.2.3-59-g8ed1b