[linux-yocto] [PATCH 1/2] serial: 8250: don't use slave_id of dma_slave_config

[wan.ahmad.zainie.wan.mohamad at intel.com]

From: Andy Shevchenko <andriy.shevchenko at linux.intel.com>

That field has been deprecated in favour of getting the necessary information
from ACPI or DT.

However, we still need to deal systems that are PCI only (no ACPI to back up)
like Intel Bay Trail. In order to support such systems, we explicitly bind
setup() to the appropriate DMA filter function and its corresponding parameter.
Then when serial8250_request_dma() doesn't find the channel via ACPI or DT, it
falls back to use the given filter function.

Signed-off-by: Andy Shevchenko <andriy.shevchenko at linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Vinod Koul <vinod.koul at intel.com>
(cherry picked from commit 9a1870ce812e13091c21af36d4dc1cd29077966d)

Signed-off-by: Maurice Petallo <mauricex.r.petallo at intel.com>
Change-Id: I4baa7e4b9f52f799b8b477913807af1a12e8ec35
Reviewed-on: https://git-gar-1.devtools.intel.com/gerrit/4364
Reviewed-by: Wan Mohamad, Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad at intel.com>
---
 drivers/tty/serial/8250/8250.h     |  6 ++---
 drivers/tty/serial/8250/8250_dw.c  |  7 +-----
 drivers/tty/serial/8250/8250_pci.c | 51 ++++++++++++++++++++++++++++++--------
 3 files changed, 44 insertions(+), 20 deletions(-)

diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
index 1ebf853..488ec04 100644
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -15,13 +15,13 @@
 #include <linux/dmaengine.h>
 
 struct uart_8250_dma {
+	/* Filter function */
 	dma_filter_fn		fn;
+
+	/* Parameter to the filter function */
 	void			*rx_param;
 	void			*tx_param;
 
-	int			rx_chan_id;
-	int			tx_chan_id;
-
 	struct dma_slave_config	rxconf;
 	struct dma_slave_config	txconf;
 
diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index 5caf10e..a8e124c 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -245,10 +245,7 @@ dw8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old)
 
 static bool dw8250_dma_filter(struct dma_chan *chan, void *param)
 {
-	struct dw8250_data *data = param;
-
-	return chan->chan_id == data->dma.tx_chan_id ||
-	       chan->chan_id == data->dma.rx_chan_id;
+	return false;
 }
 
 static void dw8250_setup_port(struct uart_8250_port *up)
@@ -417,8 +414,6 @@ static int dw8250_probe(struct platform_device *pdev)
 		uart.port.uartclk = clk_get_rate(data->clk);
 	}
 
-	data->dma.rx_chan_id = -1;
-	data->dma.tx_chan_id = -1;
 	data->dma.rx_param = data;
 	data->dma.tx_param = data;
 	data->dma.fn = dw8250_dma_filter;
diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c
index eb9bd91..6fa70b5 100644
--- a/drivers/tty/serial/8250/8250_pci.c
+++ b/drivers/tty/serial/8250/8250_pci.c
@@ -25,6 +25,9 @@
 #include <asm/byteorder.h>
 #include <asm/io.h>
 
+#include <linux/dmaengine.h>
+#include <linux/platform_data/dma-dw.h>
+
 #include "8250.h"
 
 #undef SERIAL_DEBUG_PCI
@@ -1371,7 +1374,13 @@ byt_set_termios(struct uart_port *p, struct ktermios *termios,
 
 static bool byt_dma_filter(struct dma_chan *chan, void *param)
 {
-	return chan->chan_id == *(int *)param;
+	struct dw_dma_slave *dws = param;
+
+	if (dws->dma_dev != chan->device->dev)
+		return false;
+
+	chan->private = dws;
+	return true;
 }
 
 static int
@@ -1379,35 +1388,55 @@ byt_serial_setup(struct serial_private *priv,
 		 const struct pciserial_board *board,
 		 struct uart_8250_port *port, int idx)
 {
+	struct pci_dev *pdev = priv->dev;
+	struct device *dev = port->port.dev;
 	struct uart_8250_dma *dma;
+	struct dw_dma_slave *tx_param, *rx_param;
+	struct pci_dev *dma_dev;
 	int ret;
 
-	dma = devm_kzalloc(port->port.dev, sizeof(*dma), GFP_KERNEL);
+	dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL);
 	if (!dma)
 		return -ENOMEM;
 
-	switch (priv->dev->device) {
+	tx_param = devm_kzalloc(dev, sizeof(*tx_param), GFP_KERNEL);
+	if (!tx_param)
+		return -ENOMEM;
+
+	rx_param = devm_kzalloc(dev, sizeof(*rx_param), GFP_KERNEL);
+	if (!rx_param)
+		return -ENOMEM;
+
+	switch (pdev->device) {
 	case PCI_DEVICE_ID_INTEL_BYT_UART1:
-		dma->rx_chan_id = 3;
-		dma->tx_chan_id = 2;
+		rx_param->src_id = 3;
+		tx_param->dst_id = 2;
 		break;
 	case PCI_DEVICE_ID_INTEL_BYT_UART2:
-		dma->rx_chan_id = 5;
-		dma->tx_chan_id = 4;
+		rx_param->src_id = 5;
+		tx_param->dst_id = 4;
 		break;
 	default:
 		return -EINVAL;
 	}
 
-	dma->rxconf.slave_id = dma->rx_chan_id;
+	rx_param->src_master = 1;
+	rx_param->dst_master = 0;
+
 	dma->rxconf.src_maxburst = 16;
 
-	dma->txconf.slave_id = dma->tx_chan_id;
+	tx_param->src_master = 1;
+	tx_param->dst_master = 0;
+
 	dma->txconf.dst_maxburst = 16;
 
+	dma_dev = pci_get_slot(pdev->bus, PCI_DEVFN(PCI_SLOT(pdev->devfn), 0));
+	rx_param->dma_dev = &dma_dev->dev;
+	tx_param->dma_dev = &dma_dev->dev;
+
 	dma->fn = byt_dma_filter;
-	dma->rx_param = &dma->rx_chan_id;
-	dma->tx_param = &dma->tx_chan_id;
+	dma->rx_param = rx_param;
+	dma->tx_param = tx_param;
 
 	ret = pci_default_setup(priv, board, port, idx);
 	port->port.iotype = UPIO_MEM;
-- 
1.9.1