diff options
| -rw-r--r-- | drivers/tty/serial/8250/8250_lpss.c | 78 |
1 files changed, 75 insertions, 3 deletions
diff --git a/drivers/tty/serial/8250/8250_lpss.c b/drivers/tty/serial/8250/8250_lpss.c index c0db2a8..886fcf3 100644 --- a/drivers/tty/serial/8250/8250_lpss.c +++ b/drivers/tty/serial/8250/8250_lpss.c @@ -15,7 +15,7 @@ #include <linux/rational.h> #include <linux/dmaengine.h> -#include <linux/platform_data/dma-dw.h> +#include <linux/dma/dw.h> #include "8250.h" @@ -47,6 +47,7 @@ struct lpss8250_board { unsigned long freq; unsigned int base_baud; int (*setup)(struct lpss8250 *, struct uart_port *p); + void (*exit)(struct lpss8250 *); }; struct lpss8250 { @@ -55,6 +56,7 @@ struct lpss8250 { /* DMA parameters */ struct uart_8250_dma dma; + struct dw_dma_chip dma_chip; struct dw_dma_slave dma_param; u8 dma_maxburst; }; @@ -151,6 +153,61 @@ static int byt_serial_setup(struct lpss8250 *lpss, struct uart_port *port) return 0; } +#ifdef CONFIG_SERIAL_8250_DMA +static const struct dw_dma_platform_data qrk_serial_dma_pdata = { + .nr_channels = 2, + .is_private = true, + .is_nollp = true, + .chan_allocation_order = CHAN_ALLOCATION_ASCENDING, + .chan_priority = CHAN_PRIORITY_ASCENDING, + .block_size = 4095, + .nr_masters = 1, + .data_width = {4}, +}; + +static void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port) +{ + struct uart_8250_dma *dma = &lpss->dma; + struct dw_dma_chip *chip = &lpss->dma_chip; + struct dw_dma_slave *param = &lpss->dma_param; + struct pci_dev *pdev = to_pci_dev(port->dev); + int ret; + + chip->dev = &pdev->dev; + chip->irq = pdev->irq; + chip->regs = pci_ioremap_bar(pdev, 1); + chip->pdata = &qrk_serial_dma_pdata; + + /* Falling back to PIO mode if DMA probing fails */ + ret = dw_dma_probe(chip); + if (ret) + return; + + /* Special DMA address for UART */ + dma->rx_dma_addr = 0xfffff000; + dma->tx_dma_addr = 0xfffff000; + + param->dma_dev = &pdev->dev; + param->src_id = 0; + param->dst_id = 1; + param->hs_polarity = true; + + lpss->dma_maxburst = 8; +} + +static void qrk_serial_exit_dma(struct lpss8250 *lpss) +{ + struct dw_dma_slave *param = &lpss->dma_param; + + if (!param->dma_dev) + return; + dw_dma_remove(&lpss->dma_chip); +} +#else /* CONFIG_SERIAL_8250_DMA */ +static void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port) {} +static void qrk_serial_exit_dma(struct lpss8250 *lpss) {} +#endif /* !CONFIG_SERIAL_8250_DMA */ + static int qrk_serial_setup(struct lpss8250 *lpss, struct uart_port *port) { struct pci_dev *pdev = to_pci_dev(port->dev); @@ -162,9 +219,15 @@ static int qrk_serial_setup(struct lpss8250 *lpss, struct uart_port *port) port->irq = pci_irq_vector(pdev, 0); + qrk_serial_setup_dma(lpss, port); return 0; } +static void qrk_serial_exit(struct lpss8250 *lpss) +{ + qrk_serial_exit_dma(lpss); +} + static bool lpss8250_dma_filter(struct dma_chan *chan, void *param) { struct dw_dma_slave *dws = param; @@ -247,22 +310,30 @@ static int lpss8250_probe(struct pci_dev *pdev, const struct pci_device_id *id) ret = lpss8250_dma_setup(lpss, &uart); if (ret) - return ret; + goto err_exit; ret = serial8250_register_8250_port(&uart); if (ret < 0) - return ret; + goto err_exit; lpss->line = ret; pci_set_drvdata(pdev, lpss); return 0; + +err_exit: + if (lpss->board->exit) + lpss->board->exit(lpss); + return ret; } static void lpss8250_remove(struct pci_dev *pdev) { struct lpss8250 *lpss = pci_get_drvdata(pdev); + if (lpss->board->exit) + lpss->board->exit(lpss); + serial8250_unregister_port(lpss->line); } @@ -276,6 +347,7 @@ static const struct lpss8250_board qrk_board = { .freq = 44236800, .base_baud = 2764800, .setup = qrk_serial_setup, + .exit = qrk_serial_exit, }; #define LPSS_DEVICE(id, board) { PCI_VDEVICE(INTEL, id), (kernel_ulong_t)&board } |