From ccdfe6122f61b40592820d48b4cde021295418a0 Mon Sep 17 00:00:00 2001 From: Hein_Tibosch Date: Thu, 30 Aug 2012 16:34:38 +0000 Subject: [PATCH] mmc: atmel-mci: DMA can be used with other controllers After the latest changes to atmel-mci, it could not be used with DMA on the AVR32 platform. This patch will allow to use DMA again and it will avoid access to MCI register ATMCI_DMA. Even if the IP version is lower than v3xx and doesn't have the DMA configuration register, DMA transfers can be used with a different controller than the Atmel AHB DMA one. For instance, some AVR chips use the Synopsys DesignWare AHB DMA controller. Signed-off-by: Hein Tibosch Acked-by: Ludovic Desroches Signed-off-by: Chris Ball --- drivers/mmc/host/atmel-mci.c | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c index 8c72828239b2..6823d963376e 100644 --- a/drivers/mmc/host/atmel-mci.c +++ b/drivers/mmc/host/atmel-mci.c @@ -74,7 +74,7 @@ enum atmci_pdc_buf { }; struct atmel_mci_caps { - bool has_dma; + bool has_dma_conf_reg; bool has_pdc; bool has_cfg_reg; bool has_cstor_reg; @@ -421,7 +421,7 @@ static int atmci_regs_show(struct seq_file *s, void *v) atmci_show_status_reg(s, "SR", buf[ATMCI_SR / 4]); atmci_show_status_reg(s, "IMR", buf[ATMCI_IMR / 4]); - if (host->caps.has_dma) { + if (host->caps.has_dma_conf_reg) { u32 val; val = buf[ATMCI_DMA / 4]; @@ -841,7 +841,7 @@ static void atmci_dma_complete(void *arg) dev_vdbg(&host->pdev->dev, "DMA complete\n"); - if (host->caps.has_dma) + if (host->caps.has_dma_conf_reg) /* Disable DMA hardware handshaking on MCI */ atmci_writel(host, ATMCI_DMA, atmci_readl(host, ATMCI_DMA) & ~ATMCI_DMAEN); @@ -1028,7 +1028,9 @@ atmci_prepare_data_dma(struct atmel_mci *host, struct mmc_data *data) maxburst = atmci_convert_chksize(host->dma_conf.dst_maxburst); } - atmci_writel(host, ATMCI_DMA, ATMCI_DMA_CHKSIZE(maxburst) | ATMCI_DMAEN); + if (host->caps.has_dma_conf_reg) + atmci_writel(host, ATMCI_DMA, ATMCI_DMA_CHKSIZE(maxburst) | + ATMCI_DMAEN); sglen = dma_map_sg(chan->device->dev, data->sg, data->sg_len, direction); @@ -2243,7 +2245,10 @@ static bool atmci_configure_dma(struct atmel_mci *host) pdata = host->pdev->dev.platform_data; - if (pdata && find_slave_dev(pdata->dma_slave)) { + if (!pdata) + return false; + + if (pdata->dma_slave && find_slave_dev(pdata->dma_slave)) { dma_cap_mask_t mask; /* Try to grab a DMA channel */ @@ -2284,7 +2289,7 @@ static void __init atmci_get_cap(struct atmel_mci *host) dev_info(&host->pdev->dev, "version: 0x%x\n", version); - host->caps.has_dma = 0; + host->caps.has_dma_conf_reg = 0; host->caps.has_pdc = 1; host->caps.has_cfg_reg = 0; host->caps.has_cstor_reg = 0; @@ -2302,12 +2307,7 @@ static void __init atmci_get_cap(struct atmel_mci *host) host->caps.has_odd_clk_div = 1; case 0x400: case 0x300: -#ifdef CONFIG_AT_HDMAC - host->caps.has_dma = 1; -#else - dev_info(&host->pdev->dev, - "has dma capability but dma engine is not selected, then use pio\n"); -#endif + host->caps.has_dma_conf_reg = 1; host->caps.has_pdc = 0; host->caps.has_cfg_reg = 1; host->caps.has_cstor_reg = 1; @@ -2388,7 +2388,7 @@ static int __init atmci_probe(struct platform_device *pdev) /* Get MCI capabilities and set operations according to it */ atmci_get_cap(host); - if (host->caps.has_dma && atmci_configure_dma(host)) { + if (atmci_configure_dma(host)) { host->prepare_data = &atmci_prepare_data_dma; host->submit_data = &atmci_submit_data_dma; host->stop_transfer = &atmci_stop_transfer_dma;