serial: tegra: convert to standard DMA DT bindings

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.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>

diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c
index 4455481a3517c019b836ee9827bc19cac3e7dbf3..d5c2a287b7e760728d0c38e58d08fb2361c670ee 100644 (file)
--- 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);