2 * 8250_mid.c - Driver for UART on Intel Penwell and various other Intel SOCs
4 * Copyright (C) 2015 Intel Corporation
5 * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
12 #include <linux/rational.h>
13 #include <linux/module.h>
14 #include <linux/pci.h>
16 #include <linux/dma/hsu.h>
17 #include <linux/8250_pci.h>
21 #define PCI_DEVICE_ID_INTEL_PNW_UART1 0x081b
22 #define PCI_DEVICE_ID_INTEL_PNW_UART2 0x081c
23 #define PCI_DEVICE_ID_INTEL_PNW_UART3 0x081d
24 #define PCI_DEVICE_ID_INTEL_TNG_UART 0x1191
25 #define PCI_DEVICE_ID_INTEL_DNV_UART 0x19d8
27 /* Intel MID Specific registers */
28 #define INTEL_MID_UART_DNV_FISR 0x08
29 #define INTEL_MID_UART_PS 0x30
30 #define INTEL_MID_UART_MUL 0x34
31 #define INTEL_MID_UART_DIV 0x38
35 struct mid8250_board {
38 unsigned int base_baud;
39 int (*setup)(struct mid8250 *, struct uart_port *p);
40 void (*exit)(struct mid8250 *);
46 struct pci_dev *dma_dev;
47 struct uart_8250_dma dma;
48 struct mid8250_board *board;
49 struct hsu_dma_chip dma_chip;
52 /*****************************************************************************/
54 static int pnw_setup(struct mid8250 *mid, struct uart_port *p)
56 struct pci_dev *pdev = to_pci_dev(p->dev);
58 switch (pdev->device) {
59 case PCI_DEVICE_ID_INTEL_PNW_UART1:
62 case PCI_DEVICE_ID_INTEL_PNW_UART2:
65 case PCI_DEVICE_ID_INTEL_PNW_UART3:
72 mid->dma_dev = pci_get_slot(pdev->bus,
73 PCI_DEVFN(PCI_SLOT(pdev->devfn), 3));
77 static int tng_setup(struct mid8250 *mid, struct uart_port *p)
79 struct pci_dev *pdev = to_pci_dev(p->dev);
80 int index = PCI_FUNC(pdev->devfn);
82 /* Currently no support for HSU port0 */
86 mid->dma_index = index;
87 mid->dma_dev = pci_get_slot(pdev->bus, PCI_DEVFN(5, 0));
91 static int dnv_handle_irq(struct uart_port *p)
93 struct mid8250 *mid = p->private_data;
94 unsigned int fisr = serial_port_in(p, INTEL_MID_UART_DNV_FISR);
98 ret |= hsu_dma_irq(&mid->dma_chip, 1);
100 ret |= hsu_dma_irq(&mid->dma_chip, 0);
102 ret |= serial8250_handle_irq(p, serial_port_in(p, UART_IIR));
106 #define DNV_DMA_CHAN_OFFSET 0x80
108 static int dnv_setup(struct mid8250 *mid, struct uart_port *p)
110 struct hsu_dma_chip *chip = &mid->dma_chip;
111 struct pci_dev *pdev = to_pci_dev(p->dev);
112 unsigned int bar = FL_GET_BASE(mid->board->flags);
115 chip->dev = &pdev->dev;
116 chip->irq = pdev->irq;
117 chip->regs = p->membase;
118 chip->length = pci_resource_len(pdev, bar);
119 chip->offset = DNV_DMA_CHAN_OFFSET;
121 /* Falling back to PIO mode if DMA probing fails */
122 ret = hsu_dma_probe(chip);
128 p->handle_irq = dnv_handle_irq;
132 static void dnv_exit(struct mid8250 *mid)
136 hsu_dma_remove(&mid->dma_chip);
139 /*****************************************************************************/
141 static void mid8250_set_termios(struct uart_port *p,
142 struct ktermios *termios,
143 struct ktermios *old)
145 unsigned int baud = tty_termios_baud_rate(termios);
146 struct mid8250 *mid = p->private_data;
147 unsigned short ps = 16;
148 unsigned long fuart = baud * ps;
149 unsigned long w = BIT(24) - 1;
150 unsigned long mul, div;
152 /* Gracefully handle the B0 case: fall back to B9600 */
153 fuart = fuart ? fuart : 9600 * 16;
155 if (mid->board->freq < fuart) {
156 /* Find prescaler value that satisfies Fuart < Fref */
157 if (mid->board->freq > baud)
158 ps = mid->board->freq / baud; /* baud rate too high */
160 ps = 1; /* PLL case */
163 /* Get Fuart closer to Fref */
164 fuart *= rounddown_pow_of_two(mid->board->freq / fuart);
167 rational_best_approximation(fuart, mid->board->freq, w, w, &mul, &div);
168 p->uartclk = fuart * 16 / ps; /* core uses ps = 16 always */
170 writel(ps, p->membase + INTEL_MID_UART_PS); /* set PS */
171 writel(mul, p->membase + INTEL_MID_UART_MUL); /* set MUL */
172 writel(div, p->membase + INTEL_MID_UART_DIV);
174 serial8250_do_set_termios(p, termios, old);
177 static bool mid8250_dma_filter(struct dma_chan *chan, void *param)
179 struct hsu_dma_slave *s = param;
181 if (s->dma_dev != chan->device->dev || s->chan_id != chan->chan_id)
188 static int mid8250_dma_setup(struct mid8250 *mid, struct uart_8250_port *port)
190 struct uart_8250_dma *dma = &mid->dma;
191 struct device *dev = port->port.dev;
192 struct hsu_dma_slave *rx_param;
193 struct hsu_dma_slave *tx_param;
198 rx_param = devm_kzalloc(dev, sizeof(*rx_param), GFP_KERNEL);
202 tx_param = devm_kzalloc(dev, sizeof(*tx_param), GFP_KERNEL);
206 rx_param->chan_id = mid->dma_index * 2 + 1;
207 tx_param->chan_id = mid->dma_index * 2;
209 dma->rxconf.src_maxburst = 64;
210 dma->txconf.dst_maxburst = 64;
212 rx_param->dma_dev = &mid->dma_dev->dev;
213 tx_param->dma_dev = &mid->dma_dev->dev;
215 dma->fn = mid8250_dma_filter;
216 dma->rx_param = rx_param;
217 dma->tx_param = tx_param;
223 static int mid8250_probe(struct pci_dev *pdev, const struct pci_device_id *id)
225 struct uart_8250_port uart;
230 ret = pcim_enable_device(pdev);
234 pci_set_master(pdev);
236 mid = devm_kzalloc(&pdev->dev, sizeof(*mid), GFP_KERNEL);
240 mid->board = (struct mid8250_board *)id->driver_data;
241 bar = FL_GET_BASE(mid->board->flags);
243 memset(&uart, 0, sizeof(struct uart_8250_port));
245 uart.port.dev = &pdev->dev;
246 uart.port.irq = pdev->irq;
247 uart.port.private_data = mid;
248 uart.port.type = PORT_16750;
249 uart.port.iotype = UPIO_MEM;
250 uart.port.uartclk = mid->board->base_baud * 16;
251 uart.port.flags = UPF_SHARE_IRQ | UPF_FIXED_PORT | UPF_FIXED_TYPE;
252 uart.port.set_termios = mid8250_set_termios;
254 uart.port.mapbase = pci_resource_start(pdev, bar);
255 uart.port.membase = pcim_iomap(pdev, bar, 0);
256 if (!uart.port.membase)
259 if (mid->board->setup) {
260 ret = mid->board->setup(mid, &uart.port);
265 ret = mid8250_dma_setup(mid, &uart);
269 ret = serial8250_register_8250_port(&uart);
275 pci_set_drvdata(pdev, mid);
278 if (mid->board->exit)
279 mid->board->exit(mid);
283 static void mid8250_remove(struct pci_dev *pdev)
285 struct mid8250 *mid = pci_get_drvdata(pdev);
287 if (mid->board->exit)
288 mid->board->exit(mid);
290 serial8250_unregister_port(mid->line);
293 static const struct mid8250_board pnw_board = {
300 static const struct mid8250_board tng_board = {
303 .base_baud = 1843200,
307 static const struct mid8250_board dnv_board = {
315 #define MID_DEVICE(id, board) { PCI_VDEVICE(INTEL, id), (kernel_ulong_t)&board }
317 static const struct pci_device_id pci_ids[] = {
318 MID_DEVICE(PCI_DEVICE_ID_INTEL_PNW_UART1, pnw_board),
319 MID_DEVICE(PCI_DEVICE_ID_INTEL_PNW_UART2, pnw_board),
320 MID_DEVICE(PCI_DEVICE_ID_INTEL_PNW_UART3, pnw_board),
321 MID_DEVICE(PCI_DEVICE_ID_INTEL_TNG_UART, tng_board),
322 MID_DEVICE(PCI_DEVICE_ID_INTEL_DNV_UART, dnv_board),
325 MODULE_DEVICE_TABLE(pci, pci_ids);
327 static struct pci_driver mid8250_pci_driver = {
330 .probe = mid8250_probe,
331 .remove = mid8250_remove,
334 module_pci_driver(mid8250_pci_driver);
336 MODULE_AUTHOR("Intel Corporation");
337 MODULE_LICENSE("GPL v2");
338 MODULE_DESCRIPTION("Intel MID UART driver");