On 04/07/2016 01:37 PM, Andy Shevchenko wrote:
> Intes SoCs, such as Braswell, have DesignWare UART. Split out to separate
> module which also will be used for Intel Quark later.
What's the rationale?
And this really isn't a split; this patch introduces a number of significant
changes from the pci version.
> Signed-off-by: Andy Shevchenko <andriy.shevche...@linux.intel.com>
> ---
> drivers/tty/serial/8250/8250_lpss.c | 279
> ++++++++++++++++++++++++++++++++++++
> drivers/tty/serial/8250/8250_pci.c | 227 ++---------------------------
> drivers/tty/serial/8250/Kconfig | 14 +-
> drivers/tty/serial/8250/Makefile | 1 +
> 4 files changed, 301 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..bca4adb
> --- /dev/null
> +++ b/drivers/tty/serial/8250/8250_lpss.c
> @@ -0,0 +1,279 @@
> +/*
> + * 8250_lpss.c - Driver for UART on Intel Braswell and various other Intel
> SoCs
> + *
> + * Copyright (C) 2016 Intel Corporation
> + * Author: Andy Shevchenko <andriy.shevche...@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);
> +};
New concept.
> +
> +struct lpss8250 {
> + int line;
> + struct lpss8250_board *board;
> +
> + /* DMA parameters */
> + struct uart_8250_dma dma;
> + struct dw_dma_slave dma_param;
> + u8 dma_maxburst;
> +};
> +
> +/*****************************************************************************/
Please remove.
> +
> +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);
> +}
> +
> +/*****************************************************************************/
Please remove.
> +
> +static int byt_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
This would have been much easier to review if you had simply moved it here
and done the rework in a follow-on patch.
> +{
> + 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;
> +}
> +
> +/*****************************************************************************/
Please remove.
> +
> +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 *param = &lpss->dma_param;
Unnecessary alias.
> + 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 = *param;
> + dma->rxconf.src_maxburst = lpss->dma_maxburst;
> +
> + *tx_param = *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;
> +}
> +
> +/*****************************************************************************/
Please remove.
> +
> +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_MEM32;
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;
> +
Please remove empty line
> + uart.capabilities = UART_CAP_FIFO | UART_CAP_AFE;
> +
Same
> + uart.port.mapbase = pci_resource_start(pdev, 0);
> + uart.port.membase = pcim_iomap(pdev, 0, 0);
> + if (!uart.port.membase)
> + return -ENOMEM;
> +
> + if (lpss->board->setup) {
There's no design that doesn't have a setup method.
> + ret = lpss->board->setup(lpss, &uart.port);
> + if (ret)
> + return ret;
> + }
> +
> + ret = lpss8250_dma_setup(lpss, &uart);
> + if (ret)
> + return ret;
I would fold this call into board setup which avoids the
ugliness when this error pathway is reworked in the
follow-on patches.
> +
> + 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,
No power management?
> +};
> +
> +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
>
