From: Huiquan Zhong <huiquan.zhong@xxxxxxxxx>
Intel Broxton HSUART controller have attached the Integrated DMA IP
which just have two channels[TX, RX]. Add special DMA filter function
for idma.
Signed-off-by: Huiquan Zhong <huiquan.zhong@xxxxxxxxx>
---
drivers/tty/serial/8250/8250_pci.c | 108 +++++++++++++++++++++++++++++++++++++
1 file changed, 108 insertions(+)
diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c
index 824ca72..ee8a56e 100644
--- a/drivers/tty/serial/8250/8250_pci.c
+++ b/drivers/tty/serial/8250/8250_pci.c
@@ -27,6 +27,7 @@
#include <linux/dmaengine.h>
#include <linux/platform_data/dma-dw.h>
+#include <linux/dma/dw.h>
#include "8250.h"
@@ -56,6 +57,7 @@ struct serial_private {
unsigned int nr;
void __iomem *remapped_bar[PCI_NUM_BAR_RESOURCES];
struct pci_serial_quirk *quirk;
+ struct dw_dma_chip *chip;
int line[0];
};
@@ -1547,6 +1549,11 @@ byt_serial_setup(struct serial_private *priv,
#define BXT_UART_IC_CLOCK_IDMA 0xc
#define BXT_UART_IC_CLOCK_UART 0x3
+#define BXT_UART_CAP 0x2FC
+#define IDMA_PRESENT BIT(8)
+
+#define BXT_IDMA_OFFSET 0x800
+
static void
bxt_set_termios(struct uart_port *p, struct ktermios *termios,
struct ktermios *old)
@@ -1566,11 +1573,60 @@ bxt_set_termios(struct uart_port *p, struct ktermios *termios,
serial8250_do_set_termios(p, termios, old);
}
+static bool bxt_dma_filter(struct dma_chan *chan, void *param)
+{
+ struct dw_dma_slave *dws = param;
+
+ if (dws->dma_dev != chan->device->dev)
+ return false;
+
+ chan->private = dws;
+ return true;
+}
+
+static struct dw_dma_platform_data bxt_idma_pdata = {
+ .nr_channels = 2,
+ .is_private = true,
+ .chan_allocation_order = CHAN_ALLOCATION_ASCENDING,
+ .chan_priority = CHAN_PRIORITY_ASCENDING,
+ .block_size = 0x1ffff, /* 128KB -1 */
+};
+
+static struct dw_dma_chip *bxt_idma_probe(struct device *dev,
+ void __iomem *base, int irq)
+{
+ struct dw_dma_chip *chip;
+ int err;
+
+ chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
+ if (!chip)
+ return ERR_PTR(-ENOMEM);
+
+ chip->irq = irq;
+ chip->regs = base + BXT_IDMA_OFFSET;
+ chip->type = DW_DMAC_TYPE_IDMA;
+
+ err = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(32));
+ if (err)
+ return ERR_PTR(err);
+
+ chip->dev = dev;
+ err = dw_dma_probe(chip, &bxt_idma_pdata);
+ if (err)
+ return ERR_PTR(err);
+
+ return chip;
+}
+
static int
bxt_serial_setup(struct serial_private *priv,
const struct pciserial_board *board,
struct uart_8250_port *port, int idx)
{
+ struct device *dev = port->port.dev;
+ struct uart_8250_dma *dma;
+ struct dw_dma_slave *tx_param, *rx_param;
+ unsigned int uart_cap;
int ret;
ret = pci_default_setup(priv, board, port, idx);
@@ -1582,6 +1638,50 @@ bxt_serial_setup(struct serial_private *priv,
port->tx_loadsz = 64;
port->capabilities = UART_CAP_FIFO | UART_CAP_AFE;
+ uart_cap = readl(port->port.membase + BXT_UART_CAP);
+ if (!(uart_cap & IDMA_PRESENT)) {
+ dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL);
+ if (!dma)
+ return -ENOMEM;
+
+ tx_param = devm_kzalloc(dev, sizeof(*tx_param), GFP_KERNEL);
+ if (!tx_param) {
+ ret = -ENOMEM;
+ goto err_dma_alloc;
+ }
+
+ rx_param = devm_kzalloc(dev, sizeof(*rx_param), GFP_KERNEL);
+ if (!rx_param) {
+ ret = -ENOMEM;
+ goto err_tx_param_alloc;
+ }
+
+ tx_param->dst_id = 0;
+ rx_param->src_id = 1;
+
+ dma->rxconf.src_maxburst = 8;
+ dma->rxconf.dst_maxburst = 8;
+ dma->txconf.src_maxburst = 8;
+ dma->txconf.dst_maxburst = 8;
+
+ rx_param->dma_dev = dev;
+ tx_param->dma_dev = dev;
+
+ dma->fn = bxt_dma_filter;
+ dma->rx_param = rx_param;
+ dma->tx_param = tx_param;
+
+ priv->chip = bxt_idma_probe(dev, port->port.membase,
+ port->port.irq);
+ if (!priv->chip) {
+ dev_err(dev, "error: DMA device register failed\n");
+ ret = PTR_ERR(priv->chip);
+ goto err_rx_param_alloc;
+ }
+
+ port->dma = dma;
+ }
+
/* Hw reset */
writel(0, port->port.membase + BXT_UART_RESET);
writel(BXT_UART_IDMA_RESET | BXT_UART_HOST_RESET,
@@ -1591,6 +1691,14 @@ bxt_serial_setup(struct serial_private *priv,
port->port.membase + BXT_UART_IC_CLOCK);
return ret;
+
+err_rx_param_alloc:
+ devm_kfree(dev, rx_param);
+err_tx_param_alloc:
+ devm_kfree(dev, tx_param);
+err_dma_alloc:
+ devm_kfree(dev, dma);
+ return ret;
}
static int
--
1.8.3.2
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