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.
DMA channel allocation is moved to probe() so that deferred probe works.
Cc: treding@xxxxxxxxxx
Cc: linux-tegra@xxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: linux-serial@xxxxxxxxxxxxxxx
Signed-off-by: Stephen Warren <swarren@xxxxxxxxxx>
---
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.
---
drivers/tty/serial/serial-tegra.c | 72 ++++++++++++++++-----------------------
1 file changed, 30 insertions(+), 42 deletions(-)
diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c
index 4455481a3517..e07c8bfe7459 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 +909,15 @@ 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) {
- dev_err(tup->uport.dev,
- "Dma channel is not available, will try later\n");
- return -EPROBE_DEFER;
+ dma_chan = dma_request_slave_channel_or_err(tup->uport.dev,
+ dma_to_memory ? "rx" : "tx");
+ if (IS_ERR(dma_chan)) {
+ ret = PTR_ERR(dma_chan);
+ if (ret != -EPROBE_DEFER)
+ dev_err(tup->uport.dev,
+ "DMA channel alloc failed: %d\n", ret);
+ return ret;
}
if (dma_to_memory) {
@@ -938,7 +937,6 @@ 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;
@@ -1000,37 +998,20 @@ static int tegra_uart_startup(struct uart_port *u)
struct tegra_uart_port *tup = to_tegra_uport(u);
int ret;
- ret = tegra_uart_dma_channel_allocate(tup, false);
- if (ret < 0) {
- dev_err(u->dev, "Tx Dma allocation failed, err = %d\n", ret);
- return ret;
- }
-
- ret = tegra_uart_dma_channel_allocate(tup, true);
- if (ret < 0) {
- dev_err(u->dev, "Rx Dma allocation failed, err = %d\n", ret);
- goto fail_rx_dma;
- }
-
ret = tegra_uart_hw_init(tup);
if (ret < 0) {
dev_err(u->dev, "Uart HW init failed, err = %d\n", ret);
- goto fail_hw_init;
+ return ret;
}
ret = request_irq(u->irq, tegra_uart_isr, 0,
dev_name(u->dev), tup);
if (ret < 0) {
dev_err(u->dev, "Failed to register ISR for IRQ %d\n", u->irq);
- goto fail_hw_init;
+ return ret;
}
- return 0;
-fail_hw_init:
- tegra_uart_dma_channel_free(tup, true);
-fail_rx_dma:
- tegra_uart_dma_channel_free(tup, false);
- return ret;
+ return 0;
}
static void tegra_uart_shutdown(struct uart_port *u)
@@ -1042,8 +1023,6 @@ static void tegra_uart_shutdown(struct uart_port *u)
tup->rx_in_progress = 0;
tup->tx_in_progress = 0;
- tegra_uart_dma_channel_free(tup, true);
- tegra_uart_dma_channel_free(tup, false);
free_irq(u->irq, tup);
}
@@ -1222,17 +1201,8 @@ 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);
@@ -1326,14 +1296,29 @@ static int tegra_uart_probe(struct platform_device *pdev)
return PTR_ERR(tup->rst);
}
+ ret = tegra_uart_dma_channel_allocate(tup, false);
+ if (ret < 0)
+ return ret;
+
+ ret = tegra_uart_dma_channel_allocate(tup, true);
+ if (ret < 0)
+ goto err_free_dma_tx;
+
u->iotype = UPIO_MEM32;
u->irq = platform_get_irq(pdev, 0);
u->regshift = 2;
ret = uart_add_one_port(&tegra_uart_driver, u);
if (ret < 0) {
dev_err(&pdev->dev, "Failed to add uart port, err %d\n", ret);
- return ret;
+ goto err_free_dma_rx;
}
+
+ return 0;
+
+err_free_dma_tx:
+ tegra_uart_dma_channel_free(tup, false);
+err_free_dma_rx:
+ tegra_uart_dma_channel_free(tup, true);
return ret;
}
@@ -1343,6 +1328,9 @@ static int tegra_uart_remove(struct platform_device *pdev)
struct uart_port *u = &tup->uport;
uart_remove_one_port(&tegra_uart_driver, u);
+ tegra_uart_dma_channel_free(tup, true);
+ tegra_uart_dma_channel_free(tup, false);
+
return 0;
}
--
1.8.1.5
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