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/bitops.h>
13 #include <linux/module.h>
14 #include <linux/pci.h>
15 #include <linux/rational.h>
17 #include <linux/dma/hsu.h>
18 #include <linux/8250_pci.h>
22 #define PCI_DEVICE_ID_INTEL_PNW_UART1 0x081b
23 #define PCI_DEVICE_ID_INTEL_PNW_UART2 0x081c
24 #define PCI_DEVICE_ID_INTEL_PNW_UART3 0x081d
25 #define PCI_DEVICE_ID_INTEL_TNG_UART 0x1191
26 #define PCI_DEVICE_ID_INTEL_DNV_UART 0x19d8
28 /* Intel MID Specific registers */
29 #define INTEL_MID_UART_DNV_FISR 0x08
30 #define INTEL_MID_UART_PS 0x30
31 #define INTEL_MID_UART_MUL 0x34
32 #define INTEL_MID_UART_DIV 0x38
36 struct mid8250_board {
39 unsigned int base_baud;
40 int (*setup)(struct mid8250 *, struct uart_port *p);
41 void (*exit)(struct mid8250 *);
47 struct pci_dev *dma_dev;
48 struct uart_8250_dma dma;
49 struct mid8250_board *board;
50 struct hsu_dma_chip dma_chip;
53 /*****************************************************************************/
55 static int pnw_setup(struct mid8250 *mid, struct uart_port *p)
57 struct pci_dev *pdev = to_pci_dev(p->dev);
59 switch (pdev->device) {
60 case PCI_DEVICE_ID_INTEL_PNW_UART1:
63 case PCI_DEVICE_ID_INTEL_PNW_UART2:
66 case PCI_DEVICE_ID_INTEL_PNW_UART3:
73 mid->dma_dev = pci_get_slot(pdev->bus,
74 PCI_DEVFN(PCI_SLOT(pdev->devfn), 3));
78 static int tng_handle_irq(struct uart_port *p)
80 struct mid8250 *mid = p->private_data;
81 struct uart_8250_port *up = up_to_u8250p(p);
82 struct hsu_dma_chip *chip;
87 chip = pci_get_drvdata(mid->dma_dev);
90 err = hsu_dma_get_status(chip, mid->dma_index * 2 + 1, &status);
92 serial8250_rx_dma_flush(up);
95 ret |= hsu_dma_do_irq(chip, mid->dma_index * 2 + 1, status);
98 err = hsu_dma_get_status(chip, mid->dma_index * 2, &status);
102 ret |= hsu_dma_do_irq(chip, mid->dma_index * 2, status);
105 ret |= serial8250_handle_irq(p, serial_port_in(p, UART_IIR));
106 return IRQ_RETVAL(ret);
109 static int tng_setup(struct mid8250 *mid, struct uart_port *p)
111 struct pci_dev *pdev = to_pci_dev(p->dev);
112 int index = PCI_FUNC(pdev->devfn);
115 * Device 0000:00:04.0 is not a real HSU port. It provides a global
116 * register set for all HSU ports, although it has the same PCI ID.
122 mid->dma_index = index;
123 mid->dma_dev = pci_get_slot(pdev->bus, PCI_DEVFN(5, 0));
125 p->handle_irq = tng_handle_irq;
129 static int dnv_handle_irq(struct uart_port *p)
131 struct mid8250 *mid = p->private_data;
132 struct uart_8250_port *up = up_to_u8250p(p);
133 unsigned int fisr = serial_port_in(p, INTEL_MID_UART_DNV_FISR);
139 err = hsu_dma_get_status(&mid->dma_chip, 1, &status);
141 serial8250_rx_dma_flush(up);
144 ret |= hsu_dma_do_irq(&mid->dma_chip, 1, status);
147 err = hsu_dma_get_status(&mid->dma_chip, 0, &status);
151 ret |= hsu_dma_do_irq(&mid->dma_chip, 0, status);
154 ret |= serial8250_handle_irq(p, serial_port_in(p, UART_IIR));
155 return IRQ_RETVAL(ret);
158 #define DNV_DMA_CHAN_OFFSET 0x80
160 static int dnv_setup(struct mid8250 *mid, struct uart_port *p)
162 struct hsu_dma_chip *chip = &mid->dma_chip;
163 struct pci_dev *pdev = to_pci_dev(p->dev);
164 unsigned int bar = FL_GET_BASE(mid->board->flags);
167 pci_set_master(pdev);
169 ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_ALL_TYPES);
173 p->irq = pci_irq_vector(pdev, 0);
175 chip->dev = &pdev->dev;
176 chip->irq = pci_irq_vector(pdev, 0);
177 chip->regs = p->membase;
178 chip->length = pci_resource_len(pdev, bar);
179 chip->offset = DNV_DMA_CHAN_OFFSET;
181 /* Falling back to PIO mode if DMA probing fails */
182 ret = hsu_dma_probe(chip);
188 p->handle_irq = dnv_handle_irq;
192 static void dnv_exit(struct mid8250 *mid)
196 hsu_dma_remove(&mid->dma_chip);
199 /*****************************************************************************/
201 static void mid8250_set_termios(struct uart_port *p,
202 struct ktermios *termios,
203 struct ktermios *old)
205 unsigned int baud = tty_termios_baud_rate(termios);
206 struct mid8250 *mid = p->private_data;
207 unsigned short ps = 16;
208 unsigned long fuart = baud * ps;
209 unsigned long w = BIT(24) - 1;
210 unsigned long mul, div;
212 /* Gracefully handle the B0 case: fall back to B9600 */
213 fuart = fuart ? fuart : 9600 * 16;
215 if (mid->board->freq < fuart) {
216 /* Find prescaler value that satisfies Fuart < Fref */
217 if (mid->board->freq > baud)
218 ps = mid->board->freq / baud; /* baud rate too high */
220 ps = 1; /* PLL case */
223 /* Get Fuart closer to Fref */
224 fuart *= rounddown_pow_of_two(mid->board->freq / fuart);
227 rational_best_approximation(fuart, mid->board->freq, w, w, &mul, &div);
228 p->uartclk = fuart * 16 / ps; /* core uses ps = 16 always */
230 writel(ps, p->membase + INTEL_MID_UART_PS); /* set PS */
231 writel(mul, p->membase + INTEL_MID_UART_MUL); /* set MUL */
232 writel(div, p->membase + INTEL_MID_UART_DIV);
234 serial8250_do_set_termios(p, termios, old);
237 static bool mid8250_dma_filter(struct dma_chan *chan, void *param)
239 struct hsu_dma_slave *s = param;
241 if (s->dma_dev != chan->device->dev || s->chan_id != chan->chan_id)
248 static int mid8250_dma_setup(struct mid8250 *mid, struct uart_8250_port *port)
250 struct uart_8250_dma *dma = &mid->dma;
251 struct device *dev = port->port.dev;
252 struct hsu_dma_slave *rx_param;
253 struct hsu_dma_slave *tx_param;
258 rx_param = devm_kzalloc(dev, sizeof(*rx_param), GFP_KERNEL);
262 tx_param = devm_kzalloc(dev, sizeof(*tx_param), GFP_KERNEL);
266 rx_param->chan_id = mid->dma_index * 2 + 1;
267 tx_param->chan_id = mid->dma_index * 2;
269 dma->rxconf.src_maxburst = 64;
270 dma->txconf.dst_maxburst = 64;
272 rx_param->dma_dev = &mid->dma_dev->dev;
273 tx_param->dma_dev = &mid->dma_dev->dev;
275 dma->fn = mid8250_dma_filter;
276 dma->rx_param = rx_param;
277 dma->tx_param = tx_param;
283 static int mid8250_probe(struct pci_dev *pdev, const struct pci_device_id *id)
285 struct uart_8250_port uart;
290 ret = pcim_enable_device(pdev);
294 mid = devm_kzalloc(&pdev->dev, sizeof(*mid), GFP_KERNEL);
298 mid->board = (struct mid8250_board *)id->driver_data;
299 bar = FL_GET_BASE(mid->board->flags);
301 memset(&uart, 0, sizeof(struct uart_8250_port));
303 uart.port.dev = &pdev->dev;
304 uart.port.irq = pdev->irq;
305 uart.port.private_data = mid;
306 uart.port.type = PORT_16750;
307 uart.port.iotype = UPIO_MEM;
308 uart.port.uartclk = mid->board->base_baud * 16;
309 uart.port.flags = UPF_SHARE_IRQ | UPF_FIXED_PORT | UPF_FIXED_TYPE;
310 uart.port.set_termios = mid8250_set_termios;
312 uart.port.mapbase = pci_resource_start(pdev, bar);
313 uart.port.membase = pcim_iomap(pdev, bar, 0);
314 if (!uart.port.membase)
317 if (mid->board->setup) {
318 ret = mid->board->setup(mid, &uart.port);
323 ret = mid8250_dma_setup(mid, &uart);
327 ret = serial8250_register_8250_port(&uart);
333 pci_set_drvdata(pdev, mid);
336 if (mid->board->exit)
337 mid->board->exit(mid);
341 static void mid8250_remove(struct pci_dev *pdev)
343 struct mid8250 *mid = pci_get_drvdata(pdev);
345 serial8250_unregister_port(mid->line);
347 if (mid->board->exit)
348 mid->board->exit(mid);
351 static const struct mid8250_board pnw_board = {
358 static const struct mid8250_board tng_board = {
361 .base_baud = 1843200,
365 static const struct mid8250_board dnv_board = {
373 #define MID_DEVICE(id, board) { PCI_VDEVICE(INTEL, id), (kernel_ulong_t)&board }
375 static const struct pci_device_id pci_ids[] = {
376 MID_DEVICE(PCI_DEVICE_ID_INTEL_PNW_UART1, pnw_board),
377 MID_DEVICE(PCI_DEVICE_ID_INTEL_PNW_UART2, pnw_board),
378 MID_DEVICE(PCI_DEVICE_ID_INTEL_PNW_UART3, pnw_board),
379 MID_DEVICE(PCI_DEVICE_ID_INTEL_TNG_UART, tng_board),
380 MID_DEVICE(PCI_DEVICE_ID_INTEL_DNV_UART, dnv_board),
383 MODULE_DEVICE_TABLE(pci, pci_ids);
385 static struct pci_driver mid8250_pci_driver = {
388 .probe = mid8250_probe,
389 .remove = mid8250_remove,
392 module_pci_driver(mid8250_pci_driver);
394 MODULE_AUTHOR("Intel Corporation");
395 MODULE_LICENSE("GPL v2");
396 MODULE_DESCRIPTION("Intel MID UART driver");