drivers/tty/serial/8250/8250_lpss.c - linux-imx - Git at Google

 /*
  * 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/dma/dw.h>

 #include "8250.h"

 #define PCI_DEVICE_ID_INTEL_QRK_UARTx	0x0936

 #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);
 	void (*exit)(struct lpss8250 *);
 };

 struct lpss8250 {
 	int line;
 	struct lpss8250_board *board;

 	/* DMA parameters */
 	struct uart_8250_dma dma;
 	struct dw_dma_chip dma_chip;
 	struct dw_dma_slave dma_param;
 	u8 dma_maxburst;
 };

 static void byt_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;

 	/* Gracefully handle the B0 case: fall back to B9600 */
 	fuart = fuart ? fuart : 9600 * 16;

 	/* 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 unsigned int byt_get_mctrl(struct uart_port *port)
 {
 	unsigned int ret = serial8250_do_get_mctrl(port);

 	/* Force DCD and DSR signals to permanently be reported as active */
 	ret |= TIOCM_CAR | TIOCM_DSR;

 	return ret;
 }

 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);
 	unsigned int dma_devfn = PCI_DEVFN(PCI_SLOT(pdev->devfn), 0);
 	struct pci_dev *dma_dev = pci_get_slot(pdev->bus, dma_devfn);

 	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 = byt_set_termios;
 	port->get_mctrl = byt_get_mctrl;

 	/* Disable TX counter interrupts */
 	writel(BYT_TX_OVF_INT_MASK, port->membase + BYT_TX_OVF_INT);

 	return 0;
 }

 #ifdef CONFIG_SERIAL_8250_DMA
 static const struct dw_dma_platform_data qrk_serial_dma_pdata = {
 	.nr_channels = 2,
 	.is_private = true,
 	.chan_allocation_order = CHAN_ALLOCATION_ASCENDING,
 	.chan_priority = CHAN_PRIORITY_ASCENDING,
 	.block_size = 4095,
 	.nr_masters = 1,
 	.data_width = {4},
 	.multi_block = {0},
 };

 static void 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 = pci_irq_vector(pdev, 0);
 	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;

 	pci_try_set_mwi(pdev);

 	/* 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;
 }

 static void qrk_serial_exit_dma(struct lpss8250 *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 void qrk_serial_setup_dma(struct lpss8250 *lpss, struct uart_port *port) {}
 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);
 	int ret;

 	pci_set_master(pdev);

 	ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_ALL_TYPES);
 	if (ret < 0)
 		return ret;

 	port->irq = pci_irq_vector(pdev, 0);

 	qrk_serial_setup_dma(lpss, port);
 	return 0;
 }

 static void qrk_serial_exit(struct lpss8250 *lpss)
 {
 	qrk_serial_exit_dma(lpss);
 }

 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;

 	if (!lpss->dma_param.dma_dev)
 		return 0;

 	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;

 	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)
 		goto err_exit;

 	ret = serial8250_register_8250_port(&uart);
 	if (ret < 0)
 		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);

 	serial8250_unregister_port(lpss->line);

 	if (lpss->board->exit)
 		lpss->board->exit(lpss);
 }

 static const struct lpss8250_board byt_board = {
 	.freq = 100000000,
 	.base_baud = 2764800,
 	.setup = byt_serial_setup,
 };

 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 }

 static const struct pci_device_id pci_ids[] = {
 	LPSS_DEVICE(PCI_DEVICE_ID_INTEL_QRK_UARTx, qrk_board),
 	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");
	/*
	* 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/dma/dw.h>

	#include "8250.h"

	#define PCI_DEVICE_ID_INTEL_QRK_UARTx 0x0936

	#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);
	void (exit)(struct lpss8250 );
	};

	struct lpss8250 {
	int line;
	struct lpss8250_board *board;

	/* DMA parameters */
	struct uart_8250_dma dma;
	struct dw_dma_chip dma_chip;
	struct dw_dma_slave dma_param;
	u8 dma_maxburst;
	};

	static void byt_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;

	/* Gracefully handle the B0 case: fall back to B9600 */
	fuart = fuart ? fuart : 9600 * 16;

	/* 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 unsigned int byt_get_mctrl(struct uart_port *port)
	{
	unsigned int ret = serial8250_do_get_mctrl(port);

	/* Force DCD and DSR signals to permanently be reported as active */
	ret \|= TIOCM_CAR \| TIOCM_DSR;

	return ret;
	}

	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);
	unsigned int dma_devfn = PCI_DEVFN(PCI_SLOT(pdev->devfn), 0);
	struct pci_dev *dma_dev = pci_get_slot(pdev->bus, dma_devfn);

	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 = byt_set_termios;
	port->get_mctrl = byt_get_mctrl;

	/* Disable TX counter interrupts */
	writel(BYT_TX_OVF_INT_MASK, port->membase + BYT_TX_OVF_INT);

	return 0;
	}

	#ifdef CONFIG_SERIAL_8250_DMA
	static const struct dw_dma_platform_data qrk_serial_dma_pdata = {
	.nr_channels = 2,
	.is_private = true,
	.chan_allocation_order = CHAN_ALLOCATION_ASCENDING,
	.chan_priority = CHAN_PRIORITY_ASCENDING,
	.block_size = 4095,
	.nr_masters = 1,
	.data_width = {4},
	.multi_block = {0},
	};

	static void 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 = pci_irq_vector(pdev, 0);
	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;

	pci_try_set_mwi(pdev);

	/* 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;
	}

	static void qrk_serial_exit_dma(struct lpss8250 *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 void qrk_serial_setup_dma(struct lpss8250 lpss, struct uart_port port) {}
	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);
	int ret;

	pci_set_master(pdev);

	ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_ALL_TYPES);
	if (ret < 0)
	return ret;

	port->irq = pci_irq_vector(pdev, 0);

	qrk_serial_setup_dma(lpss, port);
	return 0;
	}

	static void qrk_serial_exit(struct lpss8250 *lpss)
	{
	qrk_serial_exit_dma(lpss);
	}

	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;

	if (!lpss->dma_param.dma_dev)
	return 0;

	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;

	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)
	goto err_exit;

	ret = serial8250_register_8250_port(&uart);
	if (ret < 0)
	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);

	serial8250_unregister_port(lpss->line);

	if (lpss->board->exit)
	lpss->board->exit(lpss);
	}

	static const struct lpss8250_board byt_board = {
	.freq = 100000000,
	.base_baud = 2764800,
	.setup = byt_serial_setup,
	};

	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 }

	static const struct pci_device_id pci_ids[] = {
	LPSS_DEVICE(PCI_DEVICE_ID_INTEL_QRK_UARTx, qrk_board),
	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");