[v7,11/11] serial: 8250_lpss: enable DMA on Intel Quark UART

Commit Message

Andy Shevchenko June 17, 2016, 12:41 p.m. UTC

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

Signed-off-by: Andy Shevchenko <[e-mail]>
---
 drivers/tty/serial/8250/8250_lpss.c | 84 +++++++++++++++++++++++++++++++++++--
 1 file changed, 80 insertions(+), 4 deletions(-)

Comments

kernel test robot June 17, 2016, 1:46 p.m. UTC | #1

Hi,

[auto build test WARNING on tty/tty-testing]
[also build test WARNING on v4.7-rc3 next-20160617]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Andy-Shevchenko/serial-8250-split-LPSS-to-8250_lpss-enable-DMA-on-Quark/20160617-204834
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git tty-testing
config: x86_64-allmodconfig (attached as .config)
compiler: gcc-6 (Debian 6.1.1-1) 6.1.1 20160430
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All warnings (new ones prefixed by >>):

   drivers/tty/serial/8250/8250_lpss.c: In function 'qrk_serial_exit_dma':
>> drivers/tty/serial/8250/8250_lpss.c:202:2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
     struct dw_dma_slave *param = &lpss->dma_param;
     ^~~~~~

vim +202 drivers/tty/serial/8250/8250_lpss.c

   186		/* Special DMA address for UART */
   187		dma->rx_dma_addr = 0xfffff000;
   188		dma->tx_dma_addr = 0xfffff000;
   189	
   190		param->dma_dev = &pdev->dev;
   191		param->src_id = 0;
   192		param->dst_id = 1;
   193		param->hs_polarity = true;
   194	
   195		lpss->dma_maxburst = 8;
   196		return 0;
   197	}
   198	
   199	static void qrk_serial_exit_dma(struct lpss8250 *lpss)
   200	{
   201		qrk_serial_exit_dma(lpss);
 > 202		struct dw_dma_slave *param = &lpss->dma_param;
   203	
   204		if (!param->dma_dev)
   205			return;
   206		dw_dma_remove(&lpss->dma_chip);
   207	}
   208	#else	/* CONFIG_SERIAL_8250_DMA */
   209	static int qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port)
   210	{

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

Patch

diff --git a/drivers/tty/serial/8250/8250_lpss.c b/drivers/tty/serial/8250/8250_lpss.c
index 5ac291c..1b464cd 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 +153,66 @@  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 int 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 0;
+
+	/* 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;
+	return 0;
+}
+
+static void qrk_serial_exit_dma(struct lpss8250 *lpss)
+{
+	qrk_serial_exit_dma(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 int qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port)
+{
+	return 0;
+}
+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);
@@ -159,7 +221,12 @@  static int qrk_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
 
 	port->irq = pdev->irq;
 
-	return 0;
+	return qrk_serial_setup_dma(lpss, port);
+}
+
+static void qrk_serial_exit(struct lpss8250 *lpss)
+{
+	qrk_serial_exit_dma(lpss);
 }
 
 static bool lpss8250_dma_filter(struct dma_chan *chan, void *param)
@@ -244,22 +311,30 @@  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);
 }
 
@@ -273,6 +348,7 @@  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 }