[PATCH v2 00/11] serial: 8250: split LPSS to 8250_lpss, enable DMA on Quark

[PATCH v2 00/11] serial: 8250: split LPSS to 8250_lpss, enable DMA on Quark

[Andy Shevchenko]

This is combined series of two things:
- split out the Intel LPSS specific driver from 8250_pci into 8250_lpss
- enable DMA support on Intel Quark UART

The patch has been tested on few Intel SoCs / platforms.

This is targeting serial subsystem, thus it would be nice to get and Ack from Vinod first.
Moreover, the series depends on [1] that is now under review.

That's why I asked Vinod to create immutable tag / branch for the [1] and the
dependants (at least one more, which is sata_dwc_460ex).

The series can be reached in the branch located at [2].

[1] http://www.spinics.net/lists/dmaengine/msg08709.html
[2] https://bitbucket.org/andy-shev/linux/branch/topic%2Fdw%2Fqrk

Since v1:
- address most of Peter's comments (mostly changelog to patch 8)
- add tag to patch 5
- drop patch 6 from the series to be separately dealt with

Andy Shevchenko (11):
  dmaengine: dw: keep copy of custom slave config in dwc
  dmaengine: dw: provide probe(), remove() stubs for users
  dmaengine: dw: set polarity of handshake interface
  dmaengine: dw: override LLP support if asked in platform data
  serial: 8250_dma: switch to new dmaengine_terminate_* API
  serial: 8250_dma: adjust DMA address of the UART
  serial: 8250: enable AFE on ports where FIFO is 16 bytes
  serial: 8250_lpss: split LPSS driver to separate module
  serial: 8250_lpss: move Quark code from PCI driver
  serial: 8250_lpss: enable MSI for Intel Quark
  serial: 8250_lpss: enable DMA on Intel Quark UART

 drivers/dma/dw/core.c                |  41 ++---
 drivers/dma/dw/regs.h                |   5 +-
 drivers/tty/serial/8250/8250.h       |   5 +
 drivers/tty/serial/8250/8250_dma.c   |  14 +-
 drivers/tty/serial/8250/8250_lpss.c  | 344 +++++++++++++++++++++++++++++++++++
 drivers/tty/serial/8250/8250_pci.c   | 242 +-----------------------
 drivers/tty/serial/8250/8250_port.c  |   9 +-
 drivers/tty/serial/8250/Kconfig      |  14 +-
 drivers/tty/serial/8250/Makefile     |   1 +
 include/linux/dma/dw.h               |   5 +
 include/linux/platform_data/dma-dw.h |   4 +
 11 files changed, 413 insertions(+), 271 deletions(-)
 create mode 100644 drivers/tty/serial/8250/8250_lpss.c

-- 
2.8.0.rc3

[PATCH v2 01/11] dmaengine: dw: keep copy of custom slave config in dwc

[Andy Shevchenko]

It seems we need to extend custom slave configuration by one more member to
support Intel Quart UART. It becomes a burden to manage all members of struct
dw_dma_slave one-by-one.

Replace set of fields by embedding struct dw_dma_slave into struct dw_dma_chan.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/dma/dw/core.c | 29 ++++++++++-------------------
 drivers/dma/dw/regs.h |  5 +----
 2 files changed, 11 insertions(+), 23 deletions(-)

diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index 2b994dc..f586ba1 100644
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -46,9 +46,9 @@
 		u8 _dmsize = _is_slave ? _sconfig->dst_maxburst :	\
 			DW_DMA_MSIZE_16;			\
 		u8 _dms = (_dwc->direction == DMA_MEM_TO_DEV) ?		\
-			_dwc->p_master : _dwc->m_master;		\
+			_dwc->dws.p_master : _dwc->dws.m_master;	\
 		u8 _sms = (_dwc->direction == DMA_DEV_TO_MEM) ?		\
-			_dwc->p_master : _dwc->m_master;		\
+			_dwc->dws.p_master : _dwc->dws.m_master;	\
 								\
 		(DWC_CTLL_DST_MSIZE(_dmsize)			\
 		 | DWC_CTLL_SRC_MSIZE(_smsize)			\
@@ -140,8 +140,8 @@ static void dwc_initialize(struct dw_dma_chan *dwc)
 	if (test_bit(DW_DMA_IS_INITIALIZED, &dwc->flags))
 		return;
 
-	cfghi |= DWC_CFGH_DST_PER(dwc->dst_id);
-	cfghi |= DWC_CFGH_SRC_PER(dwc->src_id);
+	cfghi |= DWC_CFGH_DST_PER(dwc->dws.dst_id);
+	cfghi |= DWC_CFGH_SRC_PER(dwc->dws.src_id);
 
 	channel_writel(dwc, CFG_LO, cfglo);
 	channel_writel(dwc, CFG_HI, cfghi);
@@ -202,7 +202,7 @@ static inline void dwc_do_single_block(struct dw_dma_chan *dwc,
 static void dwc_dostart(struct dw_dma_chan *dwc, struct dw_desc *first)
 {
 	struct dw_dma	*dw = to_dw_dma(dwc->chan.device);
-	u8		lms = DWC_LLP_LMS(dwc->m_master);
+	u8		lms = DWC_LLP_LMS(dwc->dws.m_master);
 	unsigned long	was_soft_llp;
 
 	/* ASSERT:  channel is idle */
@@ -686,7 +686,7 @@ dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 	unsigned int		src_width;
 	unsigned int		dst_width;
 	u32			ctllo;
-	u8			lms = DWC_LLP_LMS(dwc->m_master);
+	u8			lms = DWC_LLP_LMS(dwc->dws.m_master);
 
 	dev_vdbg(chan2dev(chan),
 			"%s: d%pad s%pad l0x%zx f0x%lx\n", __func__,
@@ -759,7 +759,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 	struct dw_desc		*prev;
 	struct dw_desc		*first;
 	u32			ctllo;
-	u8			lms = DWC_LLP_LMS(dwc->m_master);
+	u8			lms = DWC_LLP_LMS(dwc->dws.m_master);
 	dma_addr_t		reg;
 	unsigned int		reg_width;
 	unsigned int		mem_width;
@@ -912,12 +912,7 @@ bool dw_dma_filter(struct dma_chan *chan, void *param)
 		return false;
 
 	/* We have to copy data since dws can be temporary storage */
-
-	dwc->src_id = dws->src_id;
-	dwc->dst_id = dws->dst_id;
-
-	dwc->m_master = dws->m_master;
-	dwc->p_master = dws->p_master;
+	memcpy(&dwc->dws, dws, sizeof(struct dw_dma_slave));
 
 	return true;
 }
@@ -1224,11 +1219,7 @@ static void dwc_free_chan_resources(struct dma_chan *chan)
 	dwc->descs_allocated = 0;
 
 	/* Clear custom channel configuration */
-	dwc->src_id = 0;
-	dwc->dst_id = 0;
-
-	dwc->m_master = 0;
-	dwc->p_master = 0;
+	memset(&dwc->dws, 0, sizeof(struct dw_dma_slave));
 
 	clear_bit(DW_DMA_IS_INITIALIZED, &dwc->flags);
 
@@ -1326,7 +1317,7 @@ struct dw_cyclic_desc *dw_dma_cyclic_prep(struct dma_chan *chan,
 	struct dw_cyclic_desc		*retval = NULL;
 	struct dw_desc			*desc;
 	struct dw_desc			*last = NULL;
-	u8				lms = DWC_LLP_LMS(dwc->m_master);
+	u8				lms = DWC_LLP_LMS(dwc->dws.m_master);
 	unsigned long			was_cyclic;
 	unsigned int			reg_width;
 	unsigned int			periods;
diff --git a/drivers/dma/dw/regs.h b/drivers/dma/dw/regs.h
index 5b3ea2d..f9e56f9 100644
--- a/drivers/dma/dw/regs.h
+++ b/drivers/dma/dw/regs.h
@@ -246,10 +246,7 @@ struct dw_dma_chan {
 	bool			nollp;
 
 	/* custom slave configuration */
-	u8			src_id;
-	u8			dst_id;
-	u8			m_master;
-	u8			p_master;
+	struct dw_dma_slave	dws;
 
 	/* configuration passed via .device_config */
 	struct dma_slave_config dma_sconfig;
-- 
2.8.0.rc3

[PATCH v2 02/11] dmaengine: dw: provide probe(), remove() stubs for users

[Andy Shevchenko]

Some users consider DMA optional, thus when driver is not compiled we shouldn't
prevent compilation of the users. Add stubs for dw_dma_probe() and
dw_dma_remove().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 include/linux/dma/dw.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/linux/dma/dw.h b/include/linux/dma/dw.h
index f2e538a..ccfd0c3 100644
--- a/include/linux/dma/dw.h
+++ b/include/linux/dma/dw.h
@@ -40,8 +40,13 @@ struct dw_dma_chip {
 };
 
 /* Export to the platform drivers */
+#if IS_ENABLED(CONFIG_DW_DMAC_CORE)
 int dw_dma_probe(struct dw_dma_chip *chip);
 int dw_dma_remove(struct dw_dma_chip *chip);
+#else
+static inline int dw_dma_probe(struct dw_dma_chip *chip) { return -ENODEV; }
+static inline int dw_dma_remove(struct dw_dma_chip *chip) { return 0; }
+#endif /* CONFIG_DW_DMAC_CORE */
 
 /* DMA API extensions */
 struct dw_desc;
-- 
2.8.0.rc3

[PATCH v2 03/11] dmaengine: dw: set polarity of handshake interface

[Andy Shevchenko]

Intel Quark UART uses DesignWare DMA IP. Though the DMA IP is connected in such
way that handshake interface uses inverted polarity. We have to provide a
possibility to set this in the DMA driver when configuring a channel.

Introduce a new member of custom slave configuration called 'polarity' and set
active low polarity in case this value is 'true'.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/dma/dw/core.c                | 2 ++
 include/linux/platform_data/dma-dw.h | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index f586ba1..57105ca 100644
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -143,6 +143,8 @@ static void dwc_initialize(struct dw_dma_chan *dwc)
 	cfghi |= DWC_CFGH_DST_PER(dwc->dws.dst_id);
 	cfghi |= DWC_CFGH_SRC_PER(dwc->dws.src_id);
 
+	cfglo |= dwc->dws.polarity ? DWC_CFGL_HS_DST_POL | DWC_CFGL_HS_SRC_POL : 0;
+
 	channel_writel(dwc, CFG_LO, cfglo);
 	channel_writel(dwc, CFG_HI, cfghi);
 
diff --git a/include/linux/platform_data/dma-dw.h b/include/linux/platform_data/dma-dw.h
index 06227d0..6196139 100644
--- a/include/linux/platform_data/dma-dw.h
+++ b/include/linux/platform_data/dma-dw.h
@@ -23,6 +23,7 @@
  * @dst_id:	dst request line
  * @m_master:	memory master for transfers on allocated channel
  * @p_master:	peripheral master for transfers on allocated channel
+ * @polarity:	set active low polarity of handshake interface
  */
 struct dw_dma_slave {
 	struct device		*dma_dev;
@@ -30,6 +31,7 @@ struct dw_dma_slave {
 	u8			dst_id;
 	u8			m_master;
 	u8			p_master;
+	bool			polarity;
 };
 
 /**
-- 
2.8.0.rc3

[PATCH v2 04/11] dmaengine: dw: override LLP support if asked in platform data

[Andy Shevchenko]

There is at least one known device, i.e. UART on Intel Galileo, that works
unreliably in case of use of multi block transfer support in DMA mode.

Override autodetection by user provided data.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/dma/dw/core.c                | 10 +++++++---
 include/linux/platform_data/dma-dw.h |  2 ++
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index 57105ca..193ecde 100644
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -1634,9 +1634,13 @@ int dw_dma_probe(struct dw_dma_chip *chip)
 			dwc->block_size = pdata->block_size;
 
 			/* Check if channel supports multi block transfer */
-			channel_writel(dwc, LLP, DWC_LLP_LOC(0xffffffff));
-			dwc->nollp = DWC_LLP_LOC(channel_readl(dwc, LLP)) == 0;
-			channel_writel(dwc, LLP, 0);
+			if (pdata->is_nollp) {
+				dwc->nollp = pdata->is_nollp;
+			} else {
+				channel_writel(dwc, LLP, DWC_LLP_LOC(0xffffffff));
+				dwc->nollp = DWC_LLP_LOC(channel_readl(dwc, LLP)) == 0;
+				channel_writel(dwc, LLP, 0);
+			}
 		}
 	}
 
diff --git a/include/linux/platform_data/dma-dw.h b/include/linux/platform_data/dma-dw.h
index 6196139..8a9d132 100644
--- a/include/linux/platform_data/dma-dw.h
+++ b/include/linux/platform_data/dma-dw.h
@@ -40,6 +40,7 @@ struct dw_dma_slave {
  * @is_private: The device channels should be marked as private and not for
  *	by the general purpose DMA channel allocator.
  * @is_memcpy: The device channels do support memory-to-memory transfers.
+ * @is_nollp: The device channels does not support multi block transfers.
  * @chan_allocation_order: Allocate channels starting from 0 or 7
  * @chan_priority: Set channel priority increasing from 0 to 7 or 7 to 0.
  * @block_size: Maximum block size supported by the controller
@@ -50,6 +51,7 @@ struct dw_dma_platform_data {
 	unsigned int	nr_channels;
 	bool		is_private;
 	bool		is_memcpy;
+	bool		is_nollp;
 #define CHAN_ALLOCATION_ASCENDING	0	/* zero to seven */
 #define CHAN_ALLOCATION_DESCENDING	1	/* seven to zero */
 	unsigned char	chan_allocation_order;
-- 
2.8.0.rc3

[PATCH v2 05/11] serial: 8250_dma: switch to new dmaengine_terminate_* API

[Andy Shevchenko]

Convert dmaengine_terminate_all() calls to synchronous and asynchronous
versions where appropriate.

Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/tty/serial/8250/8250_dma.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_dma.c b/drivers/tty/serial/8250/8250_dma.c
index 78259d3c..9d80bb1 100644
--- a/drivers/tty/serial/8250/8250_dma.c
+++ b/drivers/tty/serial/8250/8250_dma.c
@@ -127,7 +127,7 @@ int serial8250_rx_dma(struct uart_8250_port *p, unsigned int iir)
 		if (dma->rx_running) {
 			dmaengine_pause(dma->rxchan);
 			__dma_rx_complete(p);
-			dmaengine_terminate_all(dma->rxchan);
+			dmaengine_terminate_async(dma->rxchan);
 		}
 		return -ETIMEDOUT;
 	default:
@@ -230,14 +230,14 @@ void serial8250_release_dma(struct uart_8250_port *p)
 		return;
 
 	/* Release RX resources */
-	dmaengine_terminate_all(dma->rxchan);
+	dmaengine_terminate_sync(dma->rxchan);
 	dma_free_coherent(dma->rxchan->device->dev, dma->rx_size, dma->rx_buf,
 			  dma->rx_addr);
 	dma_release_channel(dma->rxchan);
 	dma->rxchan = NULL;
 
 	/* Release TX resources */
-	dmaengine_terminate_all(dma->txchan);
+	dmaengine_terminate_sync(dma->txchan);
 	dma_unmap_single(dma->txchan->device->dev, dma->tx_addr,
 			 UART_XMIT_SIZE, DMA_TO_DEVICE);
 	dma_release_channel(dma->txchan);
-- 
2.8.0.rc3

[PATCH v2 06/11] serial: 8250_dma: adjust DMA address of the UART

[Andy Shevchenko]

Some UARTs, e.g. one is used in Intel Quark, have a different address base for
DMA operations. Introduce an additional field (per RX and TX DMA channels) in
struct uart_8250_dma to cover those cases.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/tty/serial/8250/8250.h     | 5 +++++
 drivers/tty/serial/8250/8250_dma.c | 8 ++++++--
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
index 047a7ba..526ed3e 100644
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -31,6 +31,11 @@ struct uart_8250_dma {
 	struct dma_chan		*rxchan;
 	struct dma_chan		*txchan;
 
+	/* Device address base for DMA operations */
+	phys_addr_t		rx_dma_addr;
+	phys_addr_t		tx_dma_addr;
+
+	/* DMA address of the buffer in memory */
 	dma_addr_t		rx_addr;
 	dma_addr_t		tx_addr;
 
diff --git a/drivers/tty/serial/8250/8250_dma.c b/drivers/tty/serial/8250/8250_dma.c
index 9d80bb1..1553181 100644
--- a/drivers/tty/serial/8250/8250_dma.c
+++ b/drivers/tty/serial/8250/8250_dma.c
@@ -157,16 +157,20 @@ int serial8250_rx_dma(struct uart_8250_port *p, unsigned int iir)
 int serial8250_request_dma(struct uart_8250_port *p)
 {
 	struct uart_8250_dma	*dma = p->dma;
+	phys_addr_t rx_dma_addr = dma->rx_dma_addr ?
+				  dma->rx_dma_addr : p->port.mapbase;
+	phys_addr_t tx_dma_addr = dma->tx_dma_addr ?
+				  dma->tx_dma_addr : p->port.mapbase;
 	dma_cap_mask_t		mask;
 
 	/* Default slave configuration parameters */
 	dma->rxconf.direction		= DMA_DEV_TO_MEM;
 	dma->rxconf.src_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;
-	dma->rxconf.src_addr		= p->port.mapbase + UART_RX;
+	dma->rxconf.src_addr		= rx_dma_addr + UART_RX;
 
 	dma->txconf.direction		= DMA_MEM_TO_DEV;
 	dma->txconf.dst_addr_width	= DMA_SLAVE_BUSWIDTH_1_BYTE;
-	dma->txconf.dst_addr		= p->port.mapbase + UART_TX;
+	dma->txconf.dst_addr		= tx_dma_addr + UART_TX;
 
 	dma_cap_zero(mask);
 	dma_cap_set(DMA_SLAVE, mask);
-- 
2.8.0.rc3

[PATCH v2 07/11] serial: 8250: enable AFE on ports where FIFO is 16 bytes

[Andy Shevchenko]

Intel Quark has 16550A compatible UART with autoflow feature enabled. It has
only 16 bytes of FIFO. Currently serial8250_do_set_termios() prevents to enable
autoflow since the minimum requirement of 32 bytes of FIFO size.

Drop a FIFO size limitation to allow autoflow control be enabled on such UARTs.

While here, comment out UART_CAP_AFE for PORT_AR7 since it wasn't working and
it will be not a good idea to use it in conjunction with trigger level of 1
byte.

Suggested-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/tty/serial/8250/8250_port.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index e213da0..2c66fbc 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -178,7 +178,7 @@ static const struct serial8250_config uart_config[] = {
 		.fifo_size	= 16,
 		.tx_loadsz	= 16,
 		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_00,
-		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
+		.flags		= UART_CAP_FIFO /* | UART_CAP_AFE */,
 	},
 	[PORT_U6_16550A] = {
 		.name		= "U6_16550A",
@@ -2519,12 +2519,9 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
 	/*
 	 * MCR-based auto flow control.  When AFE is enabled, RTS will be
 	 * deasserted when the receive FIFO contains more characters than
-	 * the trigger, or the MCR RTS bit is cleared.  In the case where
-	 * the remote UART is not using CTS auto flow control, we must
-	 * have sufficient FIFO entries for the latency of the remote
-	 * UART to respond.  IOW, at least 32 bytes of FIFO.
+	 * the trigger, or the MCR RTS bit is cleared.
 	 */
-	if (up->capabilities & UART_CAP_AFE && port->fifosize >= 32) {
+	if (up->capabilities & UART_CAP_AFE) {
 		up->mcr &= ~UART_MCR_AFE;
 		if (termios->c_cflag & CRTSCTS)
 			up->mcr |= UART_MCR_AFE;
-- 
2.8.0.rc3

[PATCH v2 08/11] serial: 8250_lpss: split LPSS driver to separate module

[Andy Shevchenko]

The SoCs, such as Intel Braswell, have DesignWare UART IP. Split out the
support of such chips to a separate module which also will be used for Intel
Quark later.

The rationale to have the separate driver to be existing:
- Do not contaminate 8250_pci.c anymore with LPSS related quirks
- All of them are using same DMA engine and they are Designware IP which means
  that in the future we might share the code between 8250_dw.c and 8250_lpss.c
- It reduces the kernel memory footprint on non-X86 machines where 8250_pci.c
  is in use

Besides the split the driver also has been refactored, in particular a) the DMA
and port setup are separate functions, b) the two new structures lpss8250 and
lpss8250_board are introduced to keep necessary data instead of
pciserial_board, c) DMA parameters are passed to the DMA setup via mentioned
custom structure. Most of the changes are done due to the future support of
UART DMA on Intel Quark.

The Intel Quark UART DMA support is based on bits taking from BSP code
published by Intel earlier.

The driver does not use any specific power management. PCI core takes care of
the default behaviour during suspend and resume.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/tty/serial/8250/8250_lpss.c | 266 ++++++++++++++++++++++++++++++++++++
 drivers/tty/serial/8250/8250_pci.c  | 227 ++----------------------------
 drivers/tty/serial/8250/Kconfig     |  14 +-
 drivers/tty/serial/8250/Makefile    |   1 +
 4 files changed, 288 insertions(+), 220 deletions(-)
 create mode 100644 drivers/tty/serial/8250/8250_lpss.c

diff --git a/drivers/tty/serial/8250/8250_lpss.c b/drivers/tty/serial/8250/8250_lpss.c
new file mode 100644
index 0000000..3112e8b
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_lpss.c
@@ -0,0 +1,266 @@
+/*
+ * 8250_lpss.c - Driver for UART on Intel Braswell and various other Intel SoCs
+ *
+ * Copyright (C) 2016 Intel Corporation
+ * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/bitops.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/rational.h>
+
+#include <linux/dmaengine.h>
+#include <linux/platform_data/dma-dw.h>
+
+#include "8250.h"
+
+#define PCI_DEVICE_ID_INTEL_BYT_UART1	0x0f0a
+#define PCI_DEVICE_ID_INTEL_BYT_UART2	0x0f0c
+
+#define PCI_DEVICE_ID_INTEL_BSW_UART1	0x228a
+#define PCI_DEVICE_ID_INTEL_BSW_UART2	0x228c
+
+#define PCI_DEVICE_ID_INTEL_BDW_UART1	0x9ce3
+#define PCI_DEVICE_ID_INTEL_BDW_UART2	0x9ce4
+
+/* Intel LPSS specific registers */
+
+#define BYT_PRV_CLK			0x800
+#define BYT_PRV_CLK_EN			BIT(0)
+#define BYT_PRV_CLK_M_VAL_SHIFT		1
+#define BYT_PRV_CLK_N_VAL_SHIFT		16
+#define BYT_PRV_CLK_UPDATE		BIT(31)
+
+#define BYT_TX_OVF_INT			0x820
+#define BYT_TX_OVF_INT_MASK		BIT(1)
+
+struct lpss8250;
+
+struct lpss8250_board {
+	unsigned long freq;
+	unsigned int base_baud;
+	int (*setup)(struct lpss8250 *, struct uart_port *p);
+};
+
+struct lpss8250 {
+	int line;
+	struct lpss8250_board *board;
+
+	/* DMA parameters */
+	struct uart_8250_dma dma;
+	struct dw_dma_slave dma_param;
+	u8 dma_maxburst;
+};
+
+static void lpss8250_set_termios(struct uart_port *p,
+				 struct ktermios *termios,
+				 struct ktermios *old)
+{
+	unsigned int baud = tty_termios_baud_rate(termios);
+	struct lpss8250 *lpss = p->private_data;
+	unsigned long fref = lpss->board->freq, fuart = baud * 16;
+	unsigned long w = BIT(15) - 1;
+	unsigned long m, n;
+	u32 reg;
+
+	/* Get Fuart closer to Fref */
+	fuart *= rounddown_pow_of_two(fref / fuart);
+
+	/*
+	 * For baud rates 0.5M, 1M, 1.5M, 2M, 2.5M, 3M, 3.5M and 4M the
+	 * dividers must be adjusted.
+	 *
+	 * uartclk = (m / n) * 100 MHz, where m <= n
+	 */
+	rational_best_approximation(fuart, fref, w, w, &m, &n);
+	p->uartclk = fuart;
+
+	/* Reset the clock */
+	reg = (m << BYT_PRV_CLK_M_VAL_SHIFT) | (n << BYT_PRV_CLK_N_VAL_SHIFT);
+	writel(reg, p->membase + BYT_PRV_CLK);
+	reg |= BYT_PRV_CLK_EN | BYT_PRV_CLK_UPDATE;
+	writel(reg, p->membase + BYT_PRV_CLK);
+
+	p->status &= ~UPSTAT_AUTOCTS;
+	if (termios->c_cflag & CRTSCTS)
+		p->status |= UPSTAT_AUTOCTS;
+
+	serial8250_do_set_termios(p, termios, old);
+}
+
+static int byt_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
+{
+	struct dw_dma_slave *param = &lpss->dma_param;
+	struct uart_8250_port *up = up_to_u8250p(port);
+	struct pci_dev *pdev = to_pci_dev(port->dev);
+	struct pci_dev *dma_dev = pci_get_slot(pdev->bus, PCI_DEVFN(PCI_SLOT(pdev->devfn), 0));
+
+	switch (pdev->device) {
+	case PCI_DEVICE_ID_INTEL_BYT_UART1:
+	case PCI_DEVICE_ID_INTEL_BSW_UART1:
+	case PCI_DEVICE_ID_INTEL_BDW_UART1:
+		param->src_id = 3;
+		param->dst_id = 2;
+		break;
+	case PCI_DEVICE_ID_INTEL_BYT_UART2:
+	case PCI_DEVICE_ID_INTEL_BSW_UART2:
+	case PCI_DEVICE_ID_INTEL_BDW_UART2:
+		param->src_id = 5;
+		param->dst_id = 4;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	param->dma_dev = &dma_dev->dev;
+	param->m_master = 0;
+	param->p_master = 1;
+
+	/* TODO: Detect FIFO size automaticaly for DesignWare 8250 */
+	port->fifosize = 64;
+	up->tx_loadsz = 64;
+
+	lpss->dma_maxburst = 16;
+
+	port->set_termios = lpss8250_set_termios;
+
+	/* Disable TX counter interrupts */
+	writel(BYT_TX_OVF_INT_MASK, port->membase + BYT_TX_OVF_INT);
+
+	return 0;
+}
+
+static bool lpss8250_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 int lpss8250_dma_setup(struct lpss8250 *lpss, struct uart_8250_port *port)
+{
+	struct uart_8250_dma *dma = &lpss->dma;
+	struct dw_dma_slave *rx_param, *tx_param;
+	struct device *dev = port->port.dev;
+
+	rx_param = devm_kzalloc(dev, sizeof(*rx_param), GFP_KERNEL);
+	if (!rx_param)
+		return -ENOMEM;
+
+	tx_param = devm_kzalloc(dev, sizeof(*tx_param), GFP_KERNEL);
+	if (!tx_param)
+		return -ENOMEM;
+
+	*rx_param = lpss->dma_param;
+	dma->rxconf.src_maxburst = lpss->dma_maxburst;
+
+	*tx_param = lpss->dma_param;
+	dma->txconf.dst_maxburst = lpss->dma_maxburst;
+
+	dma->fn = lpss8250_dma_filter;
+	dma->rx_param = rx_param;
+	dma->tx_param = tx_param;
+
+	port->dma = dma;
+	return 0;
+}
+
+static int lpss8250_probe(struct pci_dev *pdev, const struct pci_device_id *id)
+{
+	struct uart_8250_port uart;
+	struct lpss8250 *lpss;
+	int ret;
+
+	ret = pcim_enable_device(pdev);
+	if (ret)
+		return ret;
+
+	pci_set_master(pdev);
+
+	lpss = devm_kzalloc(&pdev->dev, sizeof(*lpss), GFP_KERNEL);
+	if (!lpss)
+		return -ENOMEM;
+
+	lpss->board = (struct lpss8250_board *)id->driver_data;
+
+	memset(&uart, 0, sizeof(struct uart_8250_port));
+
+	uart.port.dev = &pdev->dev;
+	uart.port.irq = pdev->irq;
+	uart.port.private_data = lpss;
+	uart.port.type = PORT_16550A;
+	uart.port.iotype = UPIO_MEM;
+	uart.port.regshift = 2;
+	uart.port.uartclk = lpss->board->base_baud * 16;
+	uart.port.flags = UPF_SHARE_IRQ | UPF_FIXED_PORT | UPF_FIXED_TYPE;
+	uart.capabilities = UART_CAP_FIFO | UART_CAP_AFE;
+	uart.port.mapbase = pci_resource_start(pdev, 0);
+	uart.port.membase = pcim_iomap(pdev, 0, 0);
+	if (!uart.port.membase)
+		return -ENOMEM;
+
+	ret = lpss->board->setup(lpss, &uart.port);
+	if (ret)
+		return ret;
+
+	ret = lpss8250_dma_setup(lpss, &uart);
+	if (ret)
+		return ret;
+
+	ret = serial8250_register_8250_port(&uart);
+	if (ret < 0)
+		return ret;
+
+	lpss->line = ret;
+
+	pci_set_drvdata(pdev, lpss);
+	return 0;
+}
+
+static void lpss8250_remove(struct pci_dev *pdev)
+{
+	struct lpss8250 *lpss = pci_get_drvdata(pdev);
+
+	serial8250_unregister_port(lpss->line);
+}
+
+static const struct lpss8250_board byt_board = {
+	.freq = 100000000,
+	.base_baud = 2764800,
+	.setup = byt_serial_setup,
+};
+
+#define LPSS_DEVICE(id, board) { PCI_VDEVICE(INTEL, id), (kernel_ulong_t)&board }
+
+static const struct pci_device_id pci_ids[] = {
+	LPSS_DEVICE(PCI_DEVICE_ID_INTEL_BYT_UART1, byt_board),
+	LPSS_DEVICE(PCI_DEVICE_ID_INTEL_BYT_UART2, byt_board),
+	LPSS_DEVICE(PCI_DEVICE_ID_INTEL_BSW_UART1, byt_board),
+	LPSS_DEVICE(PCI_DEVICE_ID_INTEL_BSW_UART2, byt_board),
+	LPSS_DEVICE(PCI_DEVICE_ID_INTEL_BDW_UART1, byt_board),
+	LPSS_DEVICE(PCI_DEVICE_ID_INTEL_BDW_UART2, byt_board),
+	{ },
+};
+MODULE_DEVICE_TABLE(pci, pci_ids);
+
+static struct pci_driver lpss8250_pci_driver = {
+	.name           = "8250_lpss",
+	.id_table       = pci_ids,
+	.probe          = lpss8250_probe,
+	.remove         = lpss8250_remove,
+};
+
+module_pci_driver(lpss8250_pci_driver);
+
+MODULE_AUTHOR("Intel Corporation");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Intel LPSS UART driver");
diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c
index 5eea74d..bb4df5d 100644
--- a/drivers/tty/serial/8250/8250_pci.c
+++ b/drivers/tty/serial/8250/8250_pci.c
@@ -21,14 +21,10 @@
 #include <linux/serial_core.h>
 #include <linux/8250_pci.h>
 #include <linux/bitops.h>
-#include <linux/rational.h>
 
 #include <asm/byteorder.h>
 #include <asm/io.h>
 
-#include <linux/dmaengine.h>
-#include <linux/platform_data/dma-dw.h>
-
 #include "8250.h"
 
 /*
@@ -1349,145 +1345,6 @@ ce4100_serial_setup(struct serial_private *priv,
 	return ret;
 }
 
-#define PCI_DEVICE_ID_INTEL_BYT_UART1	0x0f0a
-#define PCI_DEVICE_ID_INTEL_BYT_UART2	0x0f0c
-
-#define PCI_DEVICE_ID_INTEL_BSW_UART1	0x228a
-#define PCI_DEVICE_ID_INTEL_BSW_UART2	0x228c
-
-#define PCI_DEVICE_ID_INTEL_BDW_UART1	0x9ce3
-#define PCI_DEVICE_ID_INTEL_BDW_UART2	0x9ce4
-
-#define BYT_PRV_CLK			0x800
-#define BYT_PRV_CLK_EN			(1 << 0)
-#define BYT_PRV_CLK_M_VAL_SHIFT		1
-#define BYT_PRV_CLK_N_VAL_SHIFT		16
-#define BYT_PRV_CLK_UPDATE		(1 << 31)
-
-#define BYT_TX_OVF_INT			0x820
-#define BYT_TX_OVF_INT_MASK		(1 << 1)
-
-static void
-byt_set_termios(struct uart_port *p, struct ktermios *termios,
-		struct ktermios *old)
-{
-	unsigned int baud = tty_termios_baud_rate(termios);
-	unsigned long fref = 100000000, fuart = baud * 16;
-	unsigned long w = BIT(15) - 1;
-	unsigned long m, n;
-	u32 reg;
-
-	/* Get Fuart closer to Fref */
-	fuart *= rounddown_pow_of_two(fref / fuart);
-
-	/*
-	 * For baud rates 0.5M, 1M, 1.5M, 2M, 2.5M, 3M, 3.5M and 4M the
-	 * dividers must be adjusted.
-	 *
-	 * uartclk = (m / n) * 100 MHz, where m <= n
-	 */
-	rational_best_approximation(fuart, fref, w, w, &m, &n);
-	p->uartclk = fuart;
-
-	/* Reset the clock */
-	reg = (m << BYT_PRV_CLK_M_VAL_SHIFT) | (n << BYT_PRV_CLK_N_VAL_SHIFT);
-	writel(reg, p->membase + BYT_PRV_CLK);
-	reg |= BYT_PRV_CLK_EN | BYT_PRV_CLK_UPDATE;
-	writel(reg, p->membase + BYT_PRV_CLK);
-
-	p->status &= ~UPSTAT_AUTOCTS;
-	if (termios->c_cflag & CRTSCTS)
-		p->status |= UPSTAT_AUTOCTS;
-
-	serial8250_do_set_termios(p, termios, old);
-}
-
-static bool byt_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 int
-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(dev, sizeof(*dma), GFP_KERNEL);
-	if (!dma)
-		return -ENOMEM;
-
-	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:
-	case PCI_DEVICE_ID_INTEL_BSW_UART1:
-	case PCI_DEVICE_ID_INTEL_BDW_UART1:
-		rx_param->src_id = 3;
-		tx_param->dst_id = 2;
-		break;
-	case PCI_DEVICE_ID_INTEL_BYT_UART2:
-	case PCI_DEVICE_ID_INTEL_BSW_UART2:
-	case PCI_DEVICE_ID_INTEL_BDW_UART2:
-		rx_param->src_id = 5;
-		tx_param->dst_id = 4;
-		break;
-	default:
-		return -EINVAL;
-	}
-
-	rx_param->m_master = 0;
-	rx_param->p_master = 1;
-
-	dma->rxconf.src_maxburst = 16;
-
-	tx_param->m_master = 0;
-	tx_param->p_master = 1;
-
-	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 = rx_param;
-	dma->tx_param = tx_param;
-
-	ret = pci_default_setup(priv, board, port, idx);
-	port->port.iotype = UPIO_MEM;
-	port->port.type = PORT_16550A;
-	port->port.flags = (port->port.flags | UPF_FIXED_PORT | UPF_FIXED_TYPE);
-	port->port.set_termios = byt_set_termios;
-	port->port.fifosize = 64;
-	port->tx_loadsz = 64;
-	port->dma = dma;
-	port->capabilities = UART_CAP_FIFO | UART_CAP_AFE;
-
-	/* Disable Tx counter interrupts */
-	writel(BYT_TX_OVF_INT_MASK, port->port.membase + BYT_TX_OVF_INT);
-
-	return ret;
-}
-
 static int
 pci_omegapci_setup(struct serial_private *priv,
 		      const struct pciserial_board *board,
@@ -2015,48 +1872,6 @@ static struct pci_serial_quirk pci_serial_quirks[] __refdata = {
 		.subdevice	= PCI_ANY_ID,
 		.setup		= kt_serial_setup,
 	},
-	{
-		.vendor		= PCI_VENDOR_ID_INTEL,
-		.device		= PCI_DEVICE_ID_INTEL_BYT_UART1,
-		.subvendor	= PCI_ANY_ID,
-		.subdevice	= PCI_ANY_ID,
-		.setup		= byt_serial_setup,
-	},
-	{
-		.vendor		= PCI_VENDOR_ID_INTEL,
-		.device		= PCI_DEVICE_ID_INTEL_BYT_UART2,
-		.subvendor	= PCI_ANY_ID,
-		.subdevice	= PCI_ANY_ID,
-		.setup		= byt_serial_setup,
-	},
-	{
-		.vendor		= PCI_VENDOR_ID_INTEL,
-		.device		= PCI_DEVICE_ID_INTEL_BSW_UART1,
-		.subvendor	= PCI_ANY_ID,
-		.subdevice	= PCI_ANY_ID,
-		.setup		= byt_serial_setup,
-	},
-	{
-		.vendor		= PCI_VENDOR_ID_INTEL,
-		.device		= PCI_DEVICE_ID_INTEL_BSW_UART2,
-		.subvendor	= PCI_ANY_ID,
-		.subdevice	= PCI_ANY_ID,
-		.setup		= byt_serial_setup,
-	},
-	{
-		.vendor		= PCI_VENDOR_ID_INTEL,
-		.device		= PCI_DEVICE_ID_INTEL_BDW_UART1,
-		.subvendor	= PCI_ANY_ID,
-		.subdevice	= PCI_ANY_ID,
-		.setup		= byt_serial_setup,
-	},
-	{
-		.vendor		= PCI_VENDOR_ID_INTEL,
-		.device		= PCI_DEVICE_ID_INTEL_BDW_UART2,
-		.subvendor	= PCI_ANY_ID,
-		.subdevice	= PCI_ANY_ID,
-		.setup		= byt_serial_setup,
-	},
 	/*
 	 * ITE
 	 */
@@ -2921,7 +2736,6 @@ enum pci_board_num_t {
 	pbn_ADDIDATA_PCIe_4_3906250,
 	pbn_ADDIDATA_PCIe_8_3906250,
 	pbn_ce4100_1_115200,
-	pbn_byt,
 	pbn_qrk,
 	pbn_omegapci,
 	pbn_NETMOS9900_2s_115200,
@@ -3698,12 +3512,6 @@ static struct pciserial_board pci_boards[] = {
 		.base_baud	= 921600,
 		.reg_shift      = 2,
 	},
-	[pbn_byt] = {
-		.flags		= FL_BASE0,
-		.num_ports	= 1,
-		.base_baud	= 2764800,
-		.reg_shift      = 2,
-	},
 	[pbn_qrk] = {
 		.flags		= FL_BASE0,
 		.num_ports	= 1,
@@ -3820,6 +3628,14 @@ static const struct pci_device_id blacklist[] = {
 	{ PCI_VDEVICE(INTEL, 0x081d), },
 	{ PCI_VDEVICE(INTEL, 0x1191), },
 	{ PCI_VDEVICE(INTEL, 0x19d8), },
+
+	/* Intel platforms with DesignWare UART */
+	{ PCI_VDEVICE(INTEL, 0x0f0a), },
+	{ PCI_VDEVICE(INTEL, 0x0f0c), },
+	{ PCI_VDEVICE(INTEL, 0x228a), },
+	{ PCI_VDEVICE(INTEL, 0x228c), },
+	{ PCI_VDEVICE(INTEL, 0x9ce3), },
+	{ PCI_VDEVICE(INTEL, 0x9ce4), },
 };
 
 /*
@@ -5485,33 +5301,6 @@ static struct pci_device_id serial_pci_tbl[] = {
 	{	PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_CE4100_UART,
 		PCI_ANY_ID,  PCI_ANY_ID, 0, 0,
 		pbn_ce4100_1_115200 },
-	/* Intel BayTrail */
-	{	PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_BYT_UART1,
-		PCI_ANY_ID,  PCI_ANY_ID,
-		PCI_CLASS_COMMUNICATION_SERIAL << 8, 0xff0000,
-		pbn_byt },
-	{	PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_BYT_UART2,
-		PCI_ANY_ID,  PCI_ANY_ID,
-		PCI_CLASS_COMMUNICATION_SERIAL << 8, 0xff0000,
-		pbn_byt },
-	{	PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_BSW_UART1,
-		PCI_ANY_ID,  PCI_ANY_ID,
-		PCI_CLASS_COMMUNICATION_SERIAL << 8, 0xff0000,
-		pbn_byt },
-	{	PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_BSW_UART2,
-		PCI_ANY_ID,  PCI_ANY_ID,
-		PCI_CLASS_COMMUNICATION_SERIAL << 8, 0xff0000,
-		pbn_byt },
-
-	/* Intel Broadwell */
-	{	PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_BDW_UART1,
-		PCI_ANY_ID,  PCI_ANY_ID,
-		PCI_CLASS_COMMUNICATION_SERIAL << 8, 0xff0000,
-		pbn_byt },
-	{	PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_BDW_UART2,
-		PCI_ANY_ID,  PCI_ANY_ID,
-		PCI_CLASS_COMMUNICATION_SERIAL << 8, 0xff0000,
-		pbn_byt },
 
 	/*
 	 * Intel Quark x1000
diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig
index 64742a0..6fde7d2 100644
--- a/drivers/tty/serial/8250/Kconfig
+++ b/drivers/tty/serial/8250/Kconfig
@@ -108,7 +108,6 @@ config SERIAL_8250_PCI
 	tristate "8250/16550 PCI device support" if EXPERT
 	depends on SERIAL_8250 && PCI
 	default SERIAL_8250
-	select RATIONAL
 	help
 	  This builds standard PCI serial support. You may be able to
 	  disable this feature if you only need legacy serial support.
@@ -398,6 +397,19 @@ config SERIAL_8250_INGENIC
 	  If you have a system using an Ingenic SoC and wish to make use of
 	  its UARTs, say Y to this option. If unsure, say N.
 
+config SERIAL_8250_LPSS
+	tristate "Support for serial ports on Intel LPSS platforms" if EXPERT
+	default SERIAL_8250
+	depends on SERIAL_8250 && PCI
+	depends on X86 || COMPILE_TEST
+	select DW_DMAC_CORE if SERIAL_8250_DMA
+	select DW_DMAC_PCI if X86_INTEL_LPSS
+	select RATIONAL
+	help
+	  Selecting this option will enable handling of the extra features
+	  present on the UART found on Intel Braswell SoC and various other
+	  Intel platforms.
+
 config SERIAL_8250_MID
 	tristate "Support for serial ports on Intel MID platforms"
 	depends on SERIAL_8250 && PCI
diff --git a/drivers/tty/serial/8250/Makefile b/drivers/tty/serial/8250/Makefile
index c9a2d6e..ca37d1c 100644
--- a/drivers/tty/serial/8250/Makefile
+++ b/drivers/tty/serial/8250/Makefile
@@ -28,6 +28,7 @@ obj-$(CONFIG_SERIAL_8250_LPC18XX)	+= 8250_lpc18xx.o
 obj-$(CONFIG_SERIAL_8250_MT6577)	+= 8250_mtk.o
 obj-$(CONFIG_SERIAL_8250_UNIPHIER)	+= 8250_uniphier.o
 obj-$(CONFIG_SERIAL_8250_INGENIC)	+= 8250_ingenic.o
+obj-$(CONFIG_SERIAL_8250_LPSS)		+= 8250_lpss.o
 obj-$(CONFIG_SERIAL_8250_MID)		+= 8250_mid.o
 obj-$(CONFIG_SERIAL_8250_MOXA)		+= 8250_moxa.o
 obj-$(CONFIG_SERIAL_OF_PLATFORM)	+= 8250_of.o
-- 
2.8.0.rc3

[PATCH v2 09/11] serial: 8250_lpss: move Quark code from PCI driver

[Andy Shevchenko]

Intel Quark has DesignWare UART. Move the code from 8250_pci to 8250_lpss.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/tty/serial/8250/8250_lpss.c | 11 +++++++++++
 drivers/tty/serial/8250/8250_pci.c  | 15 +--------------
 2 files changed, 12 insertions(+), 14 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_lpss.c b/drivers/tty/serial/8250/8250_lpss.c
index 3112e8b..af34189 100644
--- a/drivers/tty/serial/8250/8250_lpss.c
+++ b/drivers/tty/serial/8250/8250_lpss.c
@@ -25,6 +25,8 @@
 #define PCI_DEVICE_ID_INTEL_BSW_UART1	0x228a
 #define PCI_DEVICE_ID_INTEL_BSW_UART2	0x228c
 
+#define PCI_DEVICE_ID_INTEL_QRK_UARTx	0x0936
+
 #define PCI_DEVICE_ID_INTEL_BDW_UART1	0x9ce3
 #define PCI_DEVICE_ID_INTEL_BDW_UART2	0x9ce4
 
@@ -152,6 +154,9 @@ static int lpss8250_dma_setup(struct lpss8250 *lpss, struct uart_8250_port *port
 	struct dw_dma_slave *rx_param, *tx_param;
 	struct device *dev = port->port.dev;
 
+	if (!lpss->dma_param.dma_dev)
+		return 0;
+
 	rx_param = devm_kzalloc(dev, sizeof(*rx_param), GFP_KERNEL);
 	if (!rx_param)
 		return -ENOMEM;
@@ -239,6 +244,11 @@ static const struct lpss8250_board byt_board = {
 	.setup = byt_serial_setup,
 };
 
+static const struct lpss8250_board qrk_board = {
+	.freq = 44236800,
+	.base_baud = 2764800,
+};
+
 #define LPSS_DEVICE(id, board) { PCI_VDEVICE(INTEL, id), (kernel_ulong_t)&board }
 
 static const struct pci_device_id pci_ids[] = {
@@ -246,6 +256,7 @@ static const struct pci_device_id pci_ids[] = {
 	LPSS_DEVICE(PCI_DEVICE_ID_INTEL_BYT_UART2, byt_board),
 	LPSS_DEVICE(PCI_DEVICE_ID_INTEL_BSW_UART1, byt_board),
 	LPSS_DEVICE(PCI_DEVICE_ID_INTEL_BSW_UART2, byt_board),
+	LPSS_DEVICE(PCI_DEVICE_ID_INTEL_QRK_UARTx, qrk_board),
 	LPSS_DEVICE(PCI_DEVICE_ID_INTEL_BDW_UART1, byt_board),
 	LPSS_DEVICE(PCI_DEVICE_ID_INTEL_BDW_UART2, byt_board),
 	{ },
diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c
index bb4df5d..b94b1ee 100644
--- a/drivers/tty/serial/8250/8250_pci.c
+++ b/drivers/tty/serial/8250/8250_pci.c
@@ -1765,7 +1765,6 @@ pci_wch_ch38x_setup(struct serial_private *priv,
 #define PCI_DEVICE_ID_COMMTECH_4222PCIE	0x0022
 #define PCI_DEVICE_ID_BROADCOM_TRUMANAGE 0x160a
 #define PCI_DEVICE_ID_AMCC_ADDIDATA_APCI7800 0x818e
-#define PCI_DEVICE_ID_INTEL_QRK_UART	0x0936
 
 #define PCI_VENDOR_ID_SUNIX		0x1fd4
 #define PCI_DEVICE_ID_SUNIX_1999	0x1999
@@ -2736,7 +2735,6 @@ enum pci_board_num_t {
 	pbn_ADDIDATA_PCIe_4_3906250,
 	pbn_ADDIDATA_PCIe_8_3906250,
 	pbn_ce4100_1_115200,
-	pbn_qrk,
 	pbn_omegapci,
 	pbn_NETMOS9900_2s_115200,
 	pbn_brcm_trumanage,
@@ -3512,12 +3510,6 @@ static struct pciserial_board pci_boards[] = {
 		.base_baud	= 921600,
 		.reg_shift      = 2,
 	},
-	[pbn_qrk] = {
-		.flags		= FL_BASE0,
-		.num_ports	= 1,
-		.base_baud	= 2764800,
-		.reg_shift	= 2,
-	},
 	[pbn_omegapci] = {
 		.flags		= FL_BASE0,
 		.num_ports	= 8,
@@ -3634,6 +3626,7 @@ static const struct pci_device_id blacklist[] = {
 	{ PCI_VDEVICE(INTEL, 0x0f0c), },
 	{ PCI_VDEVICE(INTEL, 0x228a), },
 	{ PCI_VDEVICE(INTEL, 0x228c), },
+	{ PCI_VDEVICE(INTEL, 0x0936), },
 	{ PCI_VDEVICE(INTEL, 0x9ce3), },
 	{ PCI_VDEVICE(INTEL, 0x9ce4), },
 };
@@ -5303,12 +5296,6 @@ static struct pci_device_id serial_pci_tbl[] = {
 		pbn_ce4100_1_115200 },
 
 	/*
-	 * Intel Quark x1000
-	 */
-	{	PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_QRK_UART,
-		PCI_ANY_ID, PCI_ANY_ID, 0, 0,
-		pbn_qrk },
-	/*
 	 * Cronyx Omega PCI
 	 */
 	{	PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_CRONYX_OMEGA,
-- 
2.8.0.rc3

[PATCH v2 10/11] serial: 8250_lpss: enable MSI for Intel Quark

[Andy Shevchenko]

Intel Quark SoC supports MSI for LPSS, in particular for UART. Enable MSI for
Intel Quark.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/tty/serial/8250/8250_lpss.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/tty/serial/8250/8250_lpss.c b/drivers/tty/serial/8250/8250_lpss.c
index af34189..4e4abfc 100644
--- a/drivers/tty/serial/8250/8250_lpss.c
+++ b/drivers/tty/serial/8250/8250_lpss.c
@@ -137,6 +137,17 @@ static int byt_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
 	return 0;
 }
 
+static int qrk_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
+{
+	struct pci_dev *pdev = to_pci_dev(port->dev);
+
+	pci_enable_msi(pdev);
+
+	port->irq = pdev->irq;
+
+	return 0;
+}
+
 static bool lpss8250_dma_filter(struct dma_chan *chan, void *param)
 {
 	struct dw_dma_slave *dws = param;
@@ -247,6 +258,7 @@ static const struct lpss8250_board byt_board = {
 static const struct lpss8250_board qrk_board = {
 	.freq = 44236800,
 	.base_baud = 2764800,
+	.setup = qrk_serial_setup,
 };
 
 #define LPSS_DEVICE(id, board) { PCI_VDEVICE(INTEL, id), (kernel_ulong_t)&board }
-- 
2.8.0.rc3

[PATCH v2 11/11] serial: 8250_lpss: enable DMA on Intel Quark UART

[Andy Shevchenko]

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

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/tty/serial/8250/8250_lpss.c | 61 +++++++++++++++++++++++++++++++++++--
 1 file changed, 58 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_lpss.c b/drivers/tty/serial/8250/8250_lpss.c
index 4e4abfc..8848b3a 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;
 };
@@ -137,17 +139,61 @@ static int byt_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
 	return 0;
 }
 
+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(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;
 
 	pci_enable_msi(pdev);
 
 	port->irq = pdev->irq;
 
+	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->polarity = true;
+
+	lpss->dma_maxburst = 8;
 	return 0;
 }
 
+static void qrk_serial_exit(struct lpss8250 *lpss)
+{
+	struct dw_dma_slave *param = &lpss->dma_param;
+
+	if (!param->dma_dev)
+		return;
+	dw_dma_remove(&lpss->dma_chip);
+}
+
 static bool lpss8250_dma_filter(struct dma_chan *chan, void *param)
 {
 	struct dw_dma_slave *dws = param;
@@ -230,22 +276,30 @@ 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);
 }
 
@@ -259,6 +313,7 @@ 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 }
-- 
2.8.0.rc3

Re: [PATCH v2 07/11] serial: 8250: enable AFE on ports where FIFO is 16 bytes

[Peter Hurley]

On 04/11/2016 05:51 AM, Andy Shevchenko wrote:
> Intel Quark has 16550A compatible UART with autoflow feature enabled. It has
> only 16 bytes of FIFO. Currently serial8250_do_set_termios() prevents to enable
> autoflow since the minimum requirement of 32 bytes of FIFO size.
> 
> Drop a FIFO size limitation to allow autoflow control be enabled on such UARTs.
> 
> While here, comment out UART_CAP_AFE for PORT_AR7 since it wasn't working and
> it will be not a good idea to use it in conjunction with trigger level of 1
> byte.

Reviewed-by: Peter Hurley <peter@hurleysoftware.com>

Re: [PATCH v2 05/11] serial: 8250_dma: switch to new dmaengine_terminate_* API

[Heikki Krogerus]

On Mon, Apr 11, 2016 at 03:51:05PM +0300, Andy Shevchenko wrote:
> Convert dmaengine_terminate_all() calls to synchronous and asynchronous
> versions where appropriate.
> 
> Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

FWIW

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>


Thanks,

-- 
heikki

Re: [PATCH v2 06/11] serial: 8250_dma: adjust DMA address of the UART

[Heikki Krogerus]

On Mon, Apr 11, 2016 at 03:51:06PM +0300, Andy Shevchenko wrote:
> Some UARTs, e.g. one is used in Intel Quark, have a different address base for
> DMA operations. Introduce an additional field (per RX and TX DMA channels) in
> struct uart_8250_dma to cover those cases.
> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

FWIW

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>


Thanks,

-- 
heikki

Re: [PATCH v2 00/11] serial: 8250: split LPSS to 8250_lpss, enable DMA on Quark

[Vinod Koul]

On Mon, Apr 11, 2016 at 03:51:00PM +0300, Andy Shevchenko wrote:
> This is combined series of two things:
> - split out the Intel LPSS specific driver from 8250_pci into 8250_lpss
> - enable DMA support on Intel Quark UART
> 
> The patch has been tested on few Intel SoCs / platforms.
> 
> This is targeting serial subsystem, thus it would be nice to get and Ack from Vinod first.
> Moreover, the series depends on [1] that is now under review.
> 
> That's why I asked Vinod to create immutable tag / branch for the [1] and the
> dependants (at least one more, which is sata_dwc_460ex).

The dmaengine bits look fine to me but this is dependent on another dw
series which is undergoing changes.

I was thinking that it might be easier to merge the series thru dmaengine
tree if Greg is okay with it. If not once all dw patches are merged I will
give immutable signed tag

Thanks
-- 
~Vinod

Re: [PATCH v2 00/11] serial: 8250: split LPSS to 8250_lpss, enable DMA on Quark

[Andy Shevchenko]

On Wed, 2016-04-20 at 18:59 +0530, Vinod Koul wrote:
> On Mon, Apr 11, 2016 at 03:51:00PM +0300, Andy Shevchenko wrote:
> > 
> > This is combined series of two things:
> > - split out the Intel LPSS specific driver from 8250_pci into
> > 8250_lpss
> > - enable DMA support on Intel Quark UART
> > 
> > The patch has been tested on few Intel SoCs / platforms.
> > 
> > This is targeting serial subsystem, thus it would be nice to get and
> > Ack from Vinod first.
> > Moreover, the series depends on [1] that is now under review.
> > 
> > That's why I asked Vinod to create immutable tag / branch for the
> > [1] and the
> > dependants (at least one more, which is sata_dwc_460ex).
> The dmaengine bits look fine to me but this is dependent on another dw
> series which is undergoing changes.

Yes, I have to work on one patch at least (data-width property).

> 
> I was thinking that it might be easier to merge the series thru
> dmaengine
> tree if Greg is okay with it. If not once all dw patches are merged I
> will
> give immutable signed tag

It would work for me too. Greg?

-- 
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy