serial: 8250_lpss: enable DMA on Intel Quark UART

DMA on Intel Quark SoC is a part of UART IP block. Enable it.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/8250/8250_lpss.c b/drivers/tty/serial/8250/8250_lpss.c
index c0db2a8..886fcf3 100644 (file)
--- 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 }