[PATCH v2] serial: pl011: Add Device Tree support to request DMA channels

From: Lee Jones
Date: Thu Apr 18 2013 - 04:14:51 EST


The new DMA API is operational. It is now possible to request DMA
channels from information passed via Device Tree.

Cc: Russell King <linux@xxxxxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Jiri Slaby <jslaby@xxxxxxx>
Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx>
---
drivers/tty/serial/amba-pl011.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 3ea5408..1b39f58 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -249,6 +249,7 @@ static void pl011_dma_probe_initcall(struct uart_amba_port *uap)
{
/* DMA is the sole user of the platform data right now */
struct amba_pl011_data *plat = uap->port.dev->platform_data;
+ struct device_node *np = uap->port.dev->of_node;
struct dma_slave_config tx_conf = {
.dst_addr = uap->port.mapbase + UART01x_DR,
.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE,
@@ -259,9 +260,9 @@ static void pl011_dma_probe_initcall(struct uart_amba_port *uap)
struct dma_chan *chan;
dma_cap_mask_t mask;

- /* We need platform data */
- if (!plat || !plat->dma_filter) {
- dev_info(uap->port.dev, "no DMA platform data\n");
+ /* We need platform data or DT */
+ if (!(plat && plat->dma_filter) && !np) {
+ dev_info(uap->port.dev, "no DMA platform data or DT\n");
return;
}

@@ -269,7 +270,10 @@ static void pl011_dma_probe_initcall(struct uart_amba_port *uap)
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);

- chan = dma_request_channel(mask, plat->dma_filter, plat->dma_tx_param);
+ chan = dma_request_slave_channel_compat(mask,
+ (plat) ? plat->dma_filter : NULL,
+ (plat) ? plat->dma_tx_param : NULL,
+ uap->port.dev, "tx");
if (!chan) {
dev_err(uap->port.dev, "no TX DMA channel!\n");
return;
@@ -282,7 +286,7 @@ static void pl011_dma_probe_initcall(struct uart_amba_port *uap)
dma_chan_name(uap->dmatx.chan));

/* Optionally make use of an RX channel as well */
- if (plat->dma_rx_param) {
+ if ((plat && plat->dma_rx_param) || np) {
struct dma_slave_config rx_conf = {
.src_addr = uap->port.mapbase + UART01x_DR,
.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE,
@@ -291,7 +295,10 @@ static void pl011_dma_probe_initcall(struct uart_amba_port *uap)
.device_fc = false,
};

- chan = dma_request_channel(mask, plat->dma_filter, plat->dma_rx_param);
+ chan = dma_request_slave_channel_compat(mask,
+ (plat) ? plat->dma_filter : NULL,
+ (plat) ? plat->dma_rx_param : NULL,
+ uap->port.dev, "rx");
if (!chan) {
dev_err(uap->port.dev, "no RX DMA channel!\n");
return;
--
1.7.10.4

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