diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/tty/serial/8250/8250_dw.c | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c index f6eeff0..ceacf5e 100644 --- a/drivers/tty/serial/8250/8250_dw.c +++ b/drivers/tty/serial/8250/8250_dw.c @@ -27,6 +27,8 @@ #include <linux/slab.h> #include <linux/acpi.h> +#include "8250.h" + /* Offsets for the DesignWare specific registers */ #define DW_UART_USR 0x1f /* UART Status Register */ #define DW_UART_CPR 0xf4 /* Component Parameter Register */ @@ -143,9 +145,64 @@ static int dw8250_probe_of(struct uart_port *p) return 0; } +static bool dw8250_acpi_dma_filter(struct dma_chan *chan, void *parm) +{ + return chan->chan_id == *(int *)parm; +} + +static acpi_status +dw8250_acpi_walk_resource(struct acpi_resource *res, void *data) +{ + struct uart_port *p = data; + struct uart_8250_port *port; + struct uart_8250_dma *dma; + struct acpi_resource_fixed_dma *fixed_dma; + struct dma_slave_config *slave; + + port = container_of(p, struct uart_8250_port, port); + + switch (res->type) { + case ACPI_RESOURCE_TYPE_FIXED_DMA: + fixed_dma = &res->data.fixed_dma; + + /* TX comes first */ + if (!port->dma) { + dma = devm_kzalloc(p->dev, sizeof(*dma), GFP_KERNEL); + if (!dma) + return AE_NO_MEMORY; + + port->dma = dma; + slave = &dma->txconf; + + slave->direction = DMA_MEM_TO_DEV; + slave->dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; + slave->slave_id = fixed_dma->request_lines; + + dma->tx_chan_id = fixed_dma->channels; + dma->tx_param = &dma->tx_chan_id; + dma->fn = dw8250_acpi_dma_filter; + } else { + dma = port->dma; + slave = &dma->rxconf; + + slave->direction = DMA_DEV_TO_MEM; + slave->src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; + slave->slave_id = fixed_dma->request_lines; + + dma->rx_chan_id = fixed_dma->channels; + dma->rx_param = &dma->rx_chan_id; + } + + break; + } + + return AE_OK; +} + static int dw8250_probe_acpi(struct uart_port *p) { const struct acpi_device_id *id; + acpi_status status; u32 reg; id = acpi_match_device(p->dev->driver->acpi_match_table, p->dev); @@ -158,6 +215,14 @@ static int dw8250_probe_acpi(struct uart_port *p) p->regshift = 2; p->uartclk = (unsigned int)id->driver_data; + status = acpi_walk_resources(ACPI_HANDLE(p->dev), METHOD_NAME__CRS, + dw8250_acpi_walk_resource, p); + if (ACPI_FAILURE(status)) { + dev_err_ratelimited(p->dev, "%s failed \"%s\"\n", __func__, + acpi_format_exception(status)); + return -ENODEV; + } + /* Fix Haswell issue where the clocks do not get enabled */ if (!strcmp(id->id, "INT33C4") || !strcmp(id->id, "INT33C5")) { reg = readl(p->membase + LPSS_PRV_CLOCK_PARAMS); |