From: Stephen Warren <swarren@xxxxxxxxxx>
By using dma_request_slave_channel_or_err(), the DMA slave ID can be
looked up from standard DT properties, and squirrelled away during
channel allocation. Hence, there's no need to use a custom DT property
to store the slave ID.
Cc: treding@xxxxxxxxxx
Cc: linux-tegra@xxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-serial@xxxxxxxxxxxxxxx
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Stephen Warren <swarren@xxxxxxxxxx>
---
v2:
* Don't allocate DMA channels inside probe(); the DMA channel setup
relies on some buffers that don't get allocated until startup().
This patch is part of a series with strong internal depdendencies. I'm
looking for an ack so that I can take the entire series through the Tegra
and arm-soc trees. The series will be part of a stable branch that can be
merged into other subsystems if needed to avoid/resolve dependencies.
Greg, you'd previously ack'd this, but I had to change the patch to fix
some bugs, which was a fair textual change, so I dropped your ack.
---
drivers/tty/serial/serial-tegra.c | 24 ++++++------------------
1 file changed, 6 insertions(+), 18 deletions(-)
diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c
index 4455481a3517..d5c2a287b7e7 100644
--- a/drivers/tty/serial/serial-tegra.c
+++ b/drivers/tty/serial/serial-tegra.c
@@ -120,7 +120,6 @@ struct tegra_uart_port {
bool rx_timeout;
int rx_in_progress;
int symb_bit;
- int dma_req_sel;
struct dma_chan *rx_dma_chan;
struct dma_chan *tx_dma_chan;
@@ -910,15 +909,14 @@ static int tegra_uart_dma_channel_allocate(struct tegra_uart_port *tup,
dma_addr_t dma_phys;
int ret;
struct dma_slave_config dma_sconfig;
- dma_cap_mask_t mask;
- dma_cap_zero(mask);
- dma_cap_set(DMA_SLAVE, mask);
- dma_chan = dma_request_channel(mask, NULL, NULL);
- if (!dma_chan) {
+ dma_chan = dma_request_slave_channel_reason(tup->uport.dev,
+ dma_to_memory ? "rx" : "tx");
+ if (IS_ERR(dma_chan)) {
+ ret = PTR_ERR(dma_chan);
dev_err(tup->uport.dev,
- "Dma channel is not available, will try later\n");
- return -EPROBE_DEFER;
+ "DMA channel alloc failed: %d\n", ret);
+ return ret;
}
if (dma_to_memory) {
@@ -938,7 +936,6 @@ static int tegra_uart_dma_channel_allocate(struct tegra_uart_port *tup,
dma_buf = tup->uport.state->xmit.buf;
}
- dma_sconfig.slave_id = tup->dma_req_sel;
if (dma_to_memory) {
dma_sconfig.src_addr = tup->uport.mapbase;
dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
@@ -1222,17 +1219,8 @@ static int tegra_uart_parse_dt(struct platform_device *pdev,
struct tegra_uart_port *tup)
{
struct device_node *np = pdev->dev.of_node;
- u32 of_dma[2];
int port;
- if (of_property_read_u32_array(np, "nvidia,dma-request-selector",
- of_dma, 2) >= 0) {
- tup->dma_req_sel = of_dma[1];
- } else {
- dev_err(&pdev->dev, "missing dma requestor in device tree\n");
- return -EINVAL;
- }
-
port = of_alias_get_id(np, "serial");
if (port < 0) {
dev_err(&pdev->dev, "failed to get alias id, errno %d\n", port);
--
1.8.1.5
--
To unsubscribe from this list: send the line "unsubscribe linux-tegra" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
