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[deliverable/linux.git] / drivers / tty / serial / 8250 / 8250_mid.c
CommitLineData
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1/*
2 * 8250_mid.c - Driver for UART on Intel Penwell and various other Intel SOCs
3 *
4 * Copyright (C) 2015 Intel Corporation
5 * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
6 *
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.
10 */
11
dea5ac3a 12#include <linux/bitops.h>
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13#include <linux/module.h>
14#include <linux/pci.h>
dea5ac3a 15#include <linux/rational.h>
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16
17#include <linux/dma/hsu.h>
107e15fc 18#include <linux/8250_pci.h>
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19
20#include "8250.h"
21
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
6ede6dcd 26#define PCI_DEVICE_ID_INTEL_DNV_UART 0x19d8
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27
28/* Intel MID Specific registers */
c42850f1 29#define INTEL_MID_UART_DNV_FISR 0x08
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30#define INTEL_MID_UART_PS 0x30
31#define INTEL_MID_UART_MUL 0x34
32#define INTEL_MID_UART_DIV 0x38
33
34struct mid8250;
35
36struct mid8250_board {
107e15fc 37 unsigned int flags;
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38 unsigned long freq;
39 unsigned int base_baud;
40 int (*setup)(struct mid8250 *, struct uart_port *p);
6ede6dcd 41 void (*exit)(struct mid8250 *);
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42};
43
44struct mid8250 {
45 int line;
46 int dma_index;
47 struct pci_dev *dma_dev;
48 struct uart_8250_dma dma;
49 struct mid8250_board *board;
6ede6dcd 50 struct hsu_dma_chip dma_chip;
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51};
52
53/*****************************************************************************/
54
55static int pnw_setup(struct mid8250 *mid, struct uart_port *p)
56{
57 struct pci_dev *pdev = to_pci_dev(p->dev);
58
59 switch (pdev->device) {
60 case PCI_DEVICE_ID_INTEL_PNW_UART1:
61 mid->dma_index = 0;
62 break;
63 case PCI_DEVICE_ID_INTEL_PNW_UART2:
64 mid->dma_index = 1;
65 break;
66 case PCI_DEVICE_ID_INTEL_PNW_UART3:
67 mid->dma_index = 2;
68 break;
69 default:
70 return -EINVAL;
71 }
72
73 mid->dma_dev = pci_get_slot(pdev->bus,
74 PCI_DEVFN(PCI_SLOT(pdev->devfn), 3));
75 return 0;
76}
77
78static int tng_setup(struct mid8250 *mid, struct uart_port *p)
79{
80 struct pci_dev *pdev = to_pci_dev(p->dev);
81 int index = PCI_FUNC(pdev->devfn);
82
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83 /*
84 * Device 0000:00:04.0 is not a real HSU port. It provides a global
85 * register set for all HSU ports, although it has the same PCI ID.
86 * Skip it here.
87 */
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88 if (index-- == 0)
89 return -ENODEV;
90
91 mid->dma_index = index;
92 mid->dma_dev = pci_get_slot(pdev->bus, PCI_DEVFN(5, 0));
93 return 0;
94}
95
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96static int dnv_handle_irq(struct uart_port *p)
97{
98 struct mid8250 *mid = p->private_data;
692aa190 99 struct uart_8250_port *up = up_to_u8250p(p);
c42850f1 100 unsigned int fisr = serial_port_in(p, INTEL_MID_UART_DNV_FISR);
c6f82787 101 u32 status;
c42850f1 102 int ret = IRQ_NONE;
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103 int err;
104
105 if (fisr & BIT(2)) {
106 err = hsu_dma_get_status(&mid->dma_chip, 1, &status);
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107 if (err > 0) {
108 serial8250_rx_dma_flush(up);
c6f82787 109 ret |= IRQ_HANDLED;
692aa190 110 } else if (err == 0)
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111 ret |= hsu_dma_do_irq(&mid->dma_chip, 1, status);
112 }
113 if (fisr & BIT(1)) {
114 err = hsu_dma_get_status(&mid->dma_chip, 0, &status);
115 if (err > 0)
116 ret |= IRQ_HANDLED;
117 else if (err == 0)
118 ret |= hsu_dma_do_irq(&mid->dma_chip, 0, status);
119 }
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120 if (fisr & BIT(0))
121 ret |= serial8250_handle_irq(p, serial_port_in(p, UART_IIR));
122 return ret;
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123}
124
125#define DNV_DMA_CHAN_OFFSET 0x80
126
127static int dnv_setup(struct mid8250 *mid, struct uart_port *p)
128{
129 struct hsu_dma_chip *chip = &mid->dma_chip;
130 struct pci_dev *pdev = to_pci_dev(p->dev);
107e15fc 131 unsigned int bar = FL_GET_BASE(mid->board->flags);
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132 int ret;
133
134 chip->dev = &pdev->dev;
135 chip->irq = pdev->irq;
136 chip->regs = p->membase;
107e15fc 137 chip->length = pci_resource_len(pdev, bar);
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138 chip->offset = DNV_DMA_CHAN_OFFSET;
139
140 /* Falling back to PIO mode if DMA probing fails */
141 ret = hsu_dma_probe(chip);
142 if (ret)
143 return 0;
144
145 mid->dma_dev = pdev;
146
147 p->handle_irq = dnv_handle_irq;
148 return 0;
149}
150
151static void dnv_exit(struct mid8250 *mid)
152{
153 if (!mid->dma_dev)
154 return;
155 hsu_dma_remove(&mid->dma_chip);
156}
157
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158/*****************************************************************************/
159
160static void mid8250_set_termios(struct uart_port *p,
161 struct ktermios *termios,
162 struct ktermios *old)
163{
164 unsigned int baud = tty_termios_baud_rate(termios);
165 struct mid8250 *mid = p->private_data;
166 unsigned short ps = 16;
167 unsigned long fuart = baud * ps;
168 unsigned long w = BIT(24) - 1;
169 unsigned long mul, div;
170
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171 /* Gracefully handle the B0 case: fall back to B9600 */
172 fuart = fuart ? fuart : 9600 * 16;
173
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174 if (mid->board->freq < fuart) {
175 /* Find prescaler value that satisfies Fuart < Fref */
176 if (mid->board->freq > baud)
177 ps = mid->board->freq / baud; /* baud rate too high */
178 else
179 ps = 1; /* PLL case */
180 fuart = baud * ps;
181 } else {
182 /* Get Fuart closer to Fref */
183 fuart *= rounddown_pow_of_two(mid->board->freq / fuart);
184 }
185
186 rational_best_approximation(fuart, mid->board->freq, w, w, &mul, &div);
187 p->uartclk = fuart * 16 / ps; /* core uses ps = 16 always */
188
189 writel(ps, p->membase + INTEL_MID_UART_PS); /* set PS */
190 writel(mul, p->membase + INTEL_MID_UART_MUL); /* set MUL */
191 writel(div, p->membase + INTEL_MID_UART_DIV);
192
193 serial8250_do_set_termios(p, termios, old);
194}
195
196static bool mid8250_dma_filter(struct dma_chan *chan, void *param)
197{
198 struct hsu_dma_slave *s = param;
199
200 if (s->dma_dev != chan->device->dev || s->chan_id != chan->chan_id)
201 return false;
202
203 chan->private = s;
204 return true;
205}
206
207static int mid8250_dma_setup(struct mid8250 *mid, struct uart_8250_port *port)
208{
209 struct uart_8250_dma *dma = &mid->dma;
210 struct device *dev = port->port.dev;
211 struct hsu_dma_slave *rx_param;
212 struct hsu_dma_slave *tx_param;
213
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214 if (!mid->dma_dev)
215 return 0;
216
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217 rx_param = devm_kzalloc(dev, sizeof(*rx_param), GFP_KERNEL);
218 if (!rx_param)
219 return -ENOMEM;
220
221 tx_param = devm_kzalloc(dev, sizeof(*tx_param), GFP_KERNEL);
222 if (!tx_param)
223 return -ENOMEM;
224
225 rx_param->chan_id = mid->dma_index * 2 + 1;
226 tx_param->chan_id = mid->dma_index * 2;
227
228 dma->rxconf.src_maxburst = 64;
229 dma->txconf.dst_maxburst = 64;
230
231 rx_param->dma_dev = &mid->dma_dev->dev;
232 tx_param->dma_dev = &mid->dma_dev->dev;
233
234 dma->fn = mid8250_dma_filter;
235 dma->rx_param = rx_param;
236 dma->tx_param = tx_param;
237
238 port->dma = dma;
239 return 0;
240}
241
242static int mid8250_probe(struct pci_dev *pdev, const struct pci_device_id *id)
243{
244 struct uart_8250_port uart;
245 struct mid8250 *mid;
107e15fc 246 unsigned int bar;
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247 int ret;
248
249 ret = pcim_enable_device(pdev);
250 if (ret)
251 return ret;
252
253 pci_set_master(pdev);
254
255 mid = devm_kzalloc(&pdev->dev, sizeof(*mid), GFP_KERNEL);
256 if (!mid)
257 return -ENOMEM;
258
259 mid->board = (struct mid8250_board *)id->driver_data;
107e15fc 260 bar = FL_GET_BASE(mid->board->flags);
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261
262 memset(&uart, 0, sizeof(struct uart_8250_port));
263
264 uart.port.dev = &pdev->dev;
265 uart.port.irq = pdev->irq;
266 uart.port.private_data = mid;
267 uart.port.type = PORT_16750;
268 uart.port.iotype = UPIO_MEM;
269 uart.port.uartclk = mid->board->base_baud * 16;
270 uart.port.flags = UPF_SHARE_IRQ | UPF_FIXED_PORT | UPF_FIXED_TYPE;
271 uart.port.set_termios = mid8250_set_termios;
272
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273 uart.port.mapbase = pci_resource_start(pdev, bar);
274 uart.port.membase = pcim_iomap(pdev, bar, 0);
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275 if (!uart.port.membase)
276 return -ENOMEM;
277
278 if (mid->board->setup) {
279 ret = mid->board->setup(mid, &uart.port);
280 if (ret)
281 return ret;
282 }
283
284 ret = mid8250_dma_setup(mid, &uart);
285 if (ret)
6ede6dcd 286 goto err;
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287
288 ret = serial8250_register_8250_port(&uart);
289 if (ret < 0)
6ede6dcd 290 goto err;
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291
292 mid->line = ret;
293
294 pci_set_drvdata(pdev, mid);
295 return 0;
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296err:
297 if (mid->board->exit)
298 mid->board->exit(mid);
299 return ret;
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300}
301
302static void mid8250_remove(struct pci_dev *pdev)
303{
304 struct mid8250 *mid = pci_get_drvdata(pdev);
305
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306 if (mid->board->exit)
307 mid->board->exit(mid);
308
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309 serial8250_unregister_port(mid->line);
310}
311
312static const struct mid8250_board pnw_board = {
107e15fc 313 .flags = FL_BASE0,
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314 .freq = 50000000,
315 .base_baud = 115200,
316 .setup = pnw_setup,
317};
318
319static const struct mid8250_board tng_board = {
107e15fc 320 .flags = FL_BASE0,
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321 .freq = 38400000,
322 .base_baud = 1843200,
323 .setup = tng_setup,
324};
325
6ede6dcd 326static const struct mid8250_board dnv_board = {
107e15fc 327 .flags = FL_BASE1,
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328 .freq = 133333333,
329 .base_baud = 115200,
330 .setup = dnv_setup,
331 .exit = dnv_exit,
332};
333
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334#define MID_DEVICE(id, board) { PCI_VDEVICE(INTEL, id), (kernel_ulong_t)&board }
335
336static const struct pci_device_id pci_ids[] = {
337 MID_DEVICE(PCI_DEVICE_ID_INTEL_PNW_UART1, pnw_board),
338 MID_DEVICE(PCI_DEVICE_ID_INTEL_PNW_UART2, pnw_board),
339 MID_DEVICE(PCI_DEVICE_ID_INTEL_PNW_UART3, pnw_board),
340 MID_DEVICE(PCI_DEVICE_ID_INTEL_TNG_UART, tng_board),
6ede6dcd 341 MID_DEVICE(PCI_DEVICE_ID_INTEL_DNV_UART, dnv_board),
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342 { },
343};
344MODULE_DEVICE_TABLE(pci, pci_ids);
345
346static struct pci_driver mid8250_pci_driver = {
347 .name = "8250_mid",
348 .id_table = pci_ids,
349 .probe = mid8250_probe,
350 .remove = mid8250_remove,
351};
352
353module_pci_driver(mid8250_pci_driver);
354
355MODULE_AUTHOR("Intel Corporation");
356MODULE_LICENSE("GPL v2");
357MODULE_DESCRIPTION("Intel MID UART driver");
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