1 files changed, 326 insertions, 0 deletions
diff --git a/drivers/tty/serial/8250/8250_mid.c b/drivers/tty/serial/8250/8250_mid.c
new file mode 100644
index 000000000..88531a36b
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_mid.c
@@ -0,0 +1,326 @@
+/*
+ * 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/rational.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+
+#include <linux/dma/hsu.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_PS		0x30
+#define INTEL_MID_UART_MUL		0x34
+#define INTEL_MID_UART_DIV		0x38
+
+struct mid8250;
+
+struct mid8250_board {
+	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);
+
+	/* Currently no support for HSU port0 */
+	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;
+	int ret;
+
+	ret = hsu_dma_irq(&mid->dma_chip, 0);
+	ret |= hsu_dma_irq(&mid->dma_chip, 1);
+
+	/* For now, letting the HW generate separate interrupt for the UART */
+	if (ret)
+		return ret;
+
+	return serial8250_handle_irq(p, serial_port_in(p, UART_IIR));
+}
+
+#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);
+	int ret;
+
+	chip->dev = &pdev->dev;
+	chip->irq = pdev->irq;
+	chip->regs = p->membase;
+	chip->length = pci_resource_len(pdev, 0);
+	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;
+	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;
+
+	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, 0);
+	uart.port.membase = pcim_iomap(pdev, 0, 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 = {
+	.freq = 50000000,
+	.base_baud = 115200,
+	.setup = pnw_setup,
+};
+
+static const struct mid8250_board tng_board = {
+	.freq = 38400000,
+	.base_baud = 1843200,
+	.setup = tng_setup,
+};
+
+static const struct mid8250_board dnv_board = {
+	.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");