drivers/tty/serial/8250/8250_mid.c - kernel/msm-4.19 - Gitiles

 /*
  * 8250_mid.c - Driver for UART on Intel Penwell and various other Intel SOCs
  *
  * Copyright (C) 2015 Intel Corporation
  * Author: Heikki Krogerus <heikki.krogerus@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/dma/hsu.h>
 #include <linux/8250_pci.h>

 #include "8250.h"

 #define PCI_DEVICE_ID_INTEL_PNW_UART1	0x081b
 #define PCI_DEVICE_ID_INTEL_PNW_UART2	0x081c
 #define PCI_DEVICE_ID_INTEL_PNW_UART3	0x081d
 #define PCI_DEVICE_ID_INTEL_TNG_UART	0x1191
 #define PCI_DEVICE_ID_INTEL_DNV_UART	0x19d8

 /* Intel MID Specific registers */
 #define INTEL_MID_UART_DNV_FISR		0x08
 #define INTEL_MID_UART_PS		0x30
 #define INTEL_MID_UART_MUL		0x34
 #define INTEL_MID_UART_DIV		0x38

 struct mid8250;

 struct mid8250_board {
 	unsigned int flags;
 	unsigned long freq;
 	unsigned int base_baud;
 	int (*setup)(struct mid8250 *, struct uart_port *p);
 	void (*exit)(struct mid8250 *);
 };

 struct mid8250 {
 	int line;
 	int dma_index;
 	struct pci_dev *dma_dev;
 	struct uart_8250_dma dma;
 	struct mid8250_board *board;
 	struct hsu_dma_chip dma_chip;
 };

 /*****************************************************************************/

 static int pnw_setup(struct mid8250 *mid, struct uart_port *p)
 {
 	struct pci_dev *pdev = to_pci_dev(p->dev);

 	switch (pdev->device) {
 	case PCI_DEVICE_ID_INTEL_PNW_UART1:
 		mid->dma_index = 0;
 		break;
 	case PCI_DEVICE_ID_INTEL_PNW_UART2:
 		mid->dma_index = 1;
 		break;
 	case PCI_DEVICE_ID_INTEL_PNW_UART3:
 		mid->dma_index = 2;
 		break;
 	default:
 		return -EINVAL;
 	}

 	mid->dma_dev = pci_get_slot(pdev->bus,
 				    PCI_DEVFN(PCI_SLOT(pdev->devfn), 3));
 	return 0;
 }

 static int tng_setup(struct mid8250 *mid, struct uart_port *p)
 {
 	struct pci_dev *pdev = to_pci_dev(p->dev);
 	int index = PCI_FUNC(pdev->devfn);

 	/*
 	 * Device 0000:00:04.0 is not a real HSU port. It provides a global
 	 * register set for all HSU ports, although it has the same PCI ID.
 	 * Skip it here.
 	 */
 	if (index-- == 0)
 		return -ENODEV;

 	mid->dma_index = index;
 	mid->dma_dev = pci_get_slot(pdev->bus, PCI_DEVFN(5, 0));
 	return 0;
 }

 static int dnv_handle_irq(struct uart_port *p)
 {
 	struct mid8250 *mid = p->private_data;
 	struct uart_8250_port *up = up_to_u8250p(p);
 	unsigned int fisr = serial_port_in(p, INTEL_MID_UART_DNV_FISR);
 	u32 status;
 	int ret = IRQ_NONE;
 	int err;

 	if (fisr & BIT(2)) {
 		err = hsu_dma_get_status(&mid->dma_chip, 1, &status);
 		if (err > 0) {
 			serial8250_rx_dma_flush(up);
 			ret |= IRQ_HANDLED;
 		} else if (err == 0)
 			ret |= hsu_dma_do_irq(&mid->dma_chip, 1, status);
 	}
 	if (fisr & BIT(1)) {
 		err = hsu_dma_get_status(&mid->dma_chip, 0, &status);
 		if (err > 0)
 			ret |= IRQ_HANDLED;
 		else if (err == 0)
 			ret |= hsu_dma_do_irq(&mid->dma_chip, 0, status);
 	}
 	if (fisr & BIT(0))
 		ret |= serial8250_handle_irq(p, serial_port_in(p, UART_IIR));
 	return ret;
 }

 #define DNV_DMA_CHAN_OFFSET 0x80

 static int dnv_setup(struct mid8250 *mid, struct uart_port *p)
 {
 	struct hsu_dma_chip *chip = &mid->dma_chip;
 	struct pci_dev *pdev = to_pci_dev(p->dev);
 	unsigned int bar = FL_GET_BASE(mid->board->flags);
 	int ret;

 	chip->dev = &pdev->dev;
 	chip->irq = pdev->irq;
 	chip->regs = p->membase;
 	chip->length = pci_resource_len(pdev, bar);
 	chip->offset = DNV_DMA_CHAN_OFFSET;

 	/* Falling back to PIO mode if DMA probing fails */
 	ret = hsu_dma_probe(chip);
 	if (ret)
 		return 0;

 	mid->dma_dev = pdev;

 	p->handle_irq = dnv_handle_irq;
 	return 0;
 }

 static void dnv_exit(struct mid8250 *mid)
 {
 	if (!mid->dma_dev)
 		return;
 	hsu_dma_remove(&mid->dma_chip);
 }

 /*****************************************************************************/

 static void mid8250_set_termios(struct uart_port *p,
 				struct ktermios *termios,
 				struct ktermios *old)
 {
 	unsigned int baud = tty_termios_baud_rate(termios);
 	struct mid8250 *mid = p->private_data;
 	unsigned short ps = 16;
 	unsigned long fuart = baud * ps;
 	unsigned long w = BIT(24) - 1;
 	unsigned long mul, div;

 	if (mid->board->freq < fuart) {
 		/* Find prescaler value that satisfies Fuart < Fref */
 		if (mid->board->freq > baud)
 			ps = mid->board->freq / baud;	/* baud rate too high */
 		else
 			ps = 1;				/* PLL case */
 		fuart = baud * ps;
 	} else {
 		/* Get Fuart closer to Fref */
 		fuart *= rounddown_pow_of_two(mid->board->freq / fuart);
 	}

 	rational_best_approximation(fuart, mid->board->freq, w, w, &mul, &div);
 	p->uartclk = fuart * 16 / ps;		/* core uses ps = 16 always */

 	writel(ps, p->membase + INTEL_MID_UART_PS);		/* set PS */
 	writel(mul, p->membase + INTEL_MID_UART_MUL);		/* set MUL */
 	writel(div, p->membase + INTEL_MID_UART_DIV);

 	serial8250_do_set_termios(p, termios, old);
 }

 static bool mid8250_dma_filter(struct dma_chan *chan, void *param)
 {
 	struct hsu_dma_slave *s = param;

 	if (s->dma_dev != chan->device->dev || s->chan_id != chan->chan_id)
 		return false;

 	chan->private = s;
 	return true;
 }

 static int mid8250_dma_setup(struct mid8250 *mid, struct uart_8250_port *port)
 {
 	struct uart_8250_dma *dma = &mid->dma;
 	struct device *dev = port->port.dev;
 	struct hsu_dma_slave *rx_param;
 	struct hsu_dma_slave *tx_param;

 	if (!mid->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->chan_id = mid->dma_index * 2 + 1;
 	tx_param->chan_id = mid->dma_index * 2;

 	dma->rxconf.src_maxburst = 64;
 	dma->txconf.dst_maxburst = 64;

 	rx_param->dma_dev = &mid->dma_dev->dev;
 	tx_param->dma_dev = &mid->dma_dev->dev;

 	dma->fn = mid8250_dma_filter;
 	dma->rx_param = rx_param;
 	dma->tx_param = tx_param;

 	port->dma = dma;
 	return 0;
 }

 static int mid8250_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
 	struct uart_8250_port uart;
 	struct mid8250 *mid;
 	unsigned int bar;
 	int ret;

 	ret = pcim_enable_device(pdev);
 	if (ret)
 		return ret;

 	pci_set_master(pdev);

 	mid = devm_kzalloc(&pdev->dev, sizeof(*mid), GFP_KERNEL);
 	if (!mid)
 		return -ENOMEM;

 	mid->board = (struct mid8250_board *)id->driver_data;
 	bar = FL_GET_BASE(mid->board->flags);

 	memset(&uart, 0, sizeof(struct uart_8250_port));

 	uart.port.dev = &pdev->dev;
 	uart.port.irq = pdev->irq;
 	uart.port.private_data = mid;
 	uart.port.type = PORT_16750;
 	uart.port.iotype = UPIO_MEM;
 	uart.port.uartclk = mid->board->base_baud * 16;
 	uart.port.flags = UPF_SHARE_IRQ | UPF_FIXED_PORT | UPF_FIXED_TYPE;
 	uart.port.set_termios = mid8250_set_termios;

 	uart.port.mapbase = pci_resource_start(pdev, bar);
 	uart.port.membase = pcim_iomap(pdev, bar, 0);
 	if (!uart.port.membase)
 		return -ENOMEM;

 	if (mid->board->setup) {
 		ret = mid->board->setup(mid, &uart.port);
 		if (ret)
 			return ret;
 	}

 	ret = mid8250_dma_setup(mid, &uart);
 	if (ret)
 		goto err;

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

 	mid->line = ret;

 	pci_set_drvdata(pdev, mid);
 	return 0;
 err:
 	if (mid->board->exit)
 		mid->board->exit(mid);
 	return ret;
 }

 static void mid8250_remove(struct pci_dev *pdev)
 {
 	struct mid8250 *mid = pci_get_drvdata(pdev);

 	if (mid->board->exit)
 		mid->board->exit(mid);

 	serial8250_unregister_port(mid->line);
 }

 static const struct mid8250_board pnw_board = {
 	.flags = FL_BASE0,
 	.freq = 50000000,
 	.base_baud = 115200,
 	.setup = pnw_setup,
 };

 static const struct mid8250_board tng_board = {
 	.flags = FL_BASE0,
 	.freq = 38400000,
 	.base_baud = 1843200,
 	.setup = tng_setup,
 };

 static const struct mid8250_board dnv_board = {
 	.flags = FL_BASE1,
 	.freq = 133333333,
 	.base_baud = 115200,
 	.setup = dnv_setup,
 	.exit = dnv_exit,
 };

 #define MID_DEVICE(id, board) { PCI_VDEVICE(INTEL, id), (kernel_ulong_t)&board }

 static const struct pci_device_id pci_ids[] = {
 	MID_DEVICE(PCI_DEVICE_ID_INTEL_PNW_UART1, pnw_board),
 	MID_DEVICE(PCI_DEVICE_ID_INTEL_PNW_UART2, pnw_board),
 	MID_DEVICE(PCI_DEVICE_ID_INTEL_PNW_UART3, pnw_board),
 	MID_DEVICE(PCI_DEVICE_ID_INTEL_TNG_UART, tng_board),
 	MID_DEVICE(PCI_DEVICE_ID_INTEL_DNV_UART, dnv_board),
 	{ },
 };
 MODULE_DEVICE_TABLE(pci, pci_ids);

 static struct pci_driver mid8250_pci_driver = {
 	.name           = "8250_mid",
 	.id_table       = pci_ids,
 	.probe          = mid8250_probe,
 	.remove         = mid8250_remove,
 };

 module_pci_driver(mid8250_pci_driver);

 MODULE_AUTHOR("Intel Corporation");
 MODULE_LICENSE("GPL v2");
 MODULE_DESCRIPTION("Intel MID UART driver");
	/*
	* 8250_mid.c - Driver for UART on Intel Penwell and various other Intel SOCs
	*
	* Copyright (C) 2015 Intel Corporation
	* Author: Heikki Krogerus <heikki.krogerus@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/dma/hsu.h>
	#include <linux/8250_pci.h>

	#include "8250.h"

	#define PCI_DEVICE_ID_INTEL_PNW_UART1 0x081b
	#define PCI_DEVICE_ID_INTEL_PNW_UART2 0x081c
	#define PCI_DEVICE_ID_INTEL_PNW_UART3 0x081d
	#define PCI_DEVICE_ID_INTEL_TNG_UART 0x1191
	#define PCI_DEVICE_ID_INTEL_DNV_UART 0x19d8

	/* Intel MID Specific registers */
	#define INTEL_MID_UART_DNV_FISR 0x08
	#define INTEL_MID_UART_PS 0x30
	#define INTEL_MID_UART_MUL 0x34
	#define INTEL_MID_UART_DIV 0x38

	struct mid8250;

	struct mid8250_board {
	unsigned int flags;
	unsigned long freq;
	unsigned int base_baud;
	int (setup)(struct mid8250 , struct uart_port *p);
	void (exit)(struct mid8250 );
	};

	struct mid8250 {
	int line;
	int dma_index;
	struct pci_dev *dma_dev;
	struct uart_8250_dma dma;
	struct mid8250_board *board;
	struct hsu_dma_chip dma_chip;
	};

	/*****************************************************************************/

	static int pnw_setup(struct mid8250 mid, struct uart_port p)
	{
	struct pci_dev *pdev = to_pci_dev(p->dev);

	switch (pdev->device) {
	case PCI_DEVICE_ID_INTEL_PNW_UART1:
	mid->dma_index = 0;
	break;
	case PCI_DEVICE_ID_INTEL_PNW_UART2:
	mid->dma_index = 1;
	break;
	case PCI_DEVICE_ID_INTEL_PNW_UART3:
	mid->dma_index = 2;
	break;
	default:
	return -EINVAL;
	}

	mid->dma_dev = pci_get_slot(pdev->bus,
	PCI_DEVFN(PCI_SLOT(pdev->devfn), 3));
	return 0;
	}

	static int tng_setup(struct mid8250 mid, struct uart_port p)
	{
	struct pci_dev *pdev = to_pci_dev(p->dev);
	int index = PCI_FUNC(pdev->devfn);

	/*
	* Device 0000:00:04.0 is not a real HSU port. It provides a global
	* register set for all HSU ports, although it has the same PCI ID.
	* Skip it here.
	*/
	if (index-- == 0)
	return -ENODEV;

	mid->dma_index = index;
	mid->dma_dev = pci_get_slot(pdev->bus, PCI_DEVFN(5, 0));
	return 0;
	}

	static int dnv_handle_irq(struct uart_port *p)
	{
	struct mid8250 *mid = p->private_data;
	struct uart_8250_port *up = up_to_u8250p(p);
	unsigned int fisr = serial_port_in(p, INTEL_MID_UART_DNV_FISR);
	u32 status;
	int ret = IRQ_NONE;
	int err;

	if (fisr & BIT(2)) {
	err = hsu_dma_get_status(&mid->dma_chip, 1, &status);
	if (err > 0) {
	serial8250_rx_dma_flush(up);
	ret \|= IRQ_HANDLED;
	} else if (err == 0)
	ret \|= hsu_dma_do_irq(&mid->dma_chip, 1, status);
	}
	if (fisr & BIT(1)) {
	err = hsu_dma_get_status(&mid->dma_chip, 0, &status);
	if (err > 0)
	ret \|= IRQ_HANDLED;
	else if (err == 0)
	ret \|= hsu_dma_do_irq(&mid->dma_chip, 0, status);
	}
	if (fisr & BIT(0))
	ret \|= serial8250_handle_irq(p, serial_port_in(p, UART_IIR));
	return ret;
	}

	#define DNV_DMA_CHAN_OFFSET 0x80

	static int dnv_setup(struct mid8250 mid, struct uart_port p)
	{
	struct hsu_dma_chip *chip = &mid->dma_chip;
	struct pci_dev *pdev = to_pci_dev(p->dev);
	unsigned int bar = FL_GET_BASE(mid->board->flags);
	int ret;

	chip->dev = &pdev->dev;
	chip->irq = pdev->irq;
	chip->regs = p->membase;
	chip->length = pci_resource_len(pdev, bar);
	chip->offset = DNV_DMA_CHAN_OFFSET;

	/* Falling back to PIO mode if DMA probing fails */
	ret = hsu_dma_probe(chip);
	if (ret)
	return 0;

	mid->dma_dev = pdev;

	p->handle_irq = dnv_handle_irq;
	return 0;
	}

	static void dnv_exit(struct mid8250 *mid)
	{
	if (!mid->dma_dev)
	return;
	hsu_dma_remove(&mid->dma_chip);
	}

	/*****************************************************************************/

	static void mid8250_set_termios(struct uart_port *p,
	struct ktermios *termios,
	struct ktermios *old)
	{
	unsigned int baud = tty_termios_baud_rate(termios);
	struct mid8250 *mid = p->private_data;
	unsigned short ps = 16;
	unsigned long fuart = baud * ps;
	unsigned long w = BIT(24) - 1;
	unsigned long mul, div;

	if (mid->board->freq < fuart) {
	/* Find prescaler value that satisfies Fuart < Fref */
	if (mid->board->freq > baud)
	ps = mid->board->freq / baud; /* baud rate too high */
	else
	ps = 1; /* PLL case */
	fuart = baud * ps;
	} else {
	/* Get Fuart closer to Fref */
	fuart *= rounddown_pow_of_two(mid->board->freq / fuart);
	}

	rational_best_approximation(fuart, mid->board->freq, w, w, &mul, &div);
	p->uartclk = fuart * 16 / ps; /* core uses ps = 16 always */

	writel(ps, p->membase + INTEL_MID_UART_PS); /* set PS */
	writel(mul, p->membase + INTEL_MID_UART_MUL); /* set MUL */
	writel(div, p->membase + INTEL_MID_UART_DIV);

	serial8250_do_set_termios(p, termios, old);
	}

	static bool mid8250_dma_filter(struct dma_chan chan, void param)
	{
	struct hsu_dma_slave *s = param;

	if (s->dma_dev != chan->device->dev \|\| s->chan_id != chan->chan_id)
	return false;

	chan->private = s;
	return true;
	}

	static int mid8250_dma_setup(struct mid8250 mid, struct uart_8250_port port)
	{
	struct uart_8250_dma *dma = &mid->dma;
	struct device *dev = port->port.dev;
	struct hsu_dma_slave *rx_param;
	struct hsu_dma_slave *tx_param;

	if (!mid->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->chan_id = mid->dma_index * 2 + 1;
	tx_param->chan_id = mid->dma_index * 2;

	dma->rxconf.src_maxburst = 64;
	dma->txconf.dst_maxburst = 64;

	rx_param->dma_dev = &mid->dma_dev->dev;
	tx_param->dma_dev = &mid->dma_dev->dev;

	dma->fn = mid8250_dma_filter;
	dma->rx_param = rx_param;
	dma->tx_param = tx_param;

	port->dma = dma;
	return 0;
	}

	static int mid8250_probe(struct pci_dev pdev, const struct pci_device_id id)
	{
	struct uart_8250_port uart;
	struct mid8250 *mid;
	unsigned int bar;
	int ret;

	ret = pcim_enable_device(pdev);
	if (ret)
	return ret;

	pci_set_master(pdev);

	mid = devm_kzalloc(&pdev->dev, sizeof(*mid), GFP_KERNEL);
	if (!mid)
	return -ENOMEM;

	mid->board = (struct mid8250_board *)id->driver_data;
	bar = FL_GET_BASE(mid->board->flags);

	memset(&uart, 0, sizeof(struct uart_8250_port));

	uart.port.dev = &pdev->dev;
	uart.port.irq = pdev->irq;
	uart.port.private_data = mid;
	uart.port.type = PORT_16750;
	uart.port.iotype = UPIO_MEM;
	uart.port.uartclk = mid->board->base_baud * 16;
	uart.port.flags = UPF_SHARE_IRQ \| UPF_FIXED_PORT \| UPF_FIXED_TYPE;
	uart.port.set_termios = mid8250_set_termios;

	uart.port.mapbase = pci_resource_start(pdev, bar);
	uart.port.membase = pcim_iomap(pdev, bar, 0);
	if (!uart.port.membase)
	return -ENOMEM;

	if (mid->board->setup) {
	ret = mid->board->setup(mid, &uart.port);
	if (ret)
	return ret;
	}

	ret = mid8250_dma_setup(mid, &uart);
	if (ret)
	goto err;

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

	mid->line = ret;

	pci_set_drvdata(pdev, mid);
	return 0;
	err:
	if (mid->board->exit)
	mid->board->exit(mid);
	return ret;
	}

	static void mid8250_remove(struct pci_dev *pdev)
	{
	struct mid8250 *mid = pci_get_drvdata(pdev);

	if (mid->board->exit)
	mid->board->exit(mid);

	serial8250_unregister_port(mid->line);
	}

	static const struct mid8250_board pnw_board = {
	.flags = FL_BASE0,
	.freq = 50000000,
	.base_baud = 115200,
	.setup = pnw_setup,
	};

	static const struct mid8250_board tng_board = {
	.flags = FL_BASE0,
	.freq = 38400000,
	.base_baud = 1843200,
	.setup = tng_setup,
	};

	static const struct mid8250_board dnv_board = {
	.flags = FL_BASE1,
	.freq = 133333333,
	.base_baud = 115200,
	.setup = dnv_setup,
	.exit = dnv_exit,
	};

	#define MID_DEVICE(id, board) { PCI_VDEVICE(INTEL, id), (kernel_ulong_t)&board }

	static const struct pci_device_id pci_ids[] = {
	MID_DEVICE(PCI_DEVICE_ID_INTEL_PNW_UART1, pnw_board),
	MID_DEVICE(PCI_DEVICE_ID_INTEL_PNW_UART2, pnw_board),
	MID_DEVICE(PCI_DEVICE_ID_INTEL_PNW_UART3, pnw_board),
	MID_DEVICE(PCI_DEVICE_ID_INTEL_TNG_UART, tng_board),
	MID_DEVICE(PCI_DEVICE_ID_INTEL_DNV_UART, dnv_board),
	{ },
	};
	MODULE_DEVICE_TABLE(pci, pci_ids);

	static struct pci_driver mid8250_pci_driver = {
	.name = "8250_mid",
	.id_table = pci_ids,
	.probe = mid8250_probe,
	.remove = mid8250_remove,
	};

	module_pci_driver(mid8250_pci_driver);

	MODULE_AUTHOR("Intel Corporation");
	MODULE_LICENSE("GPL v2");
	MODULE_DESCRIPTION("Intel MID UART driver");