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 <hein_tibosch@yahoo.es>
Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index 8c72828..6823d96 100644
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -74,7 +74,7 @@
};
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
/* 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;