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_setup(struct mid8250 *mid, struct uart_port *p)
80 struct pci_dev *pdev = to_pci_dev(p->dev);
81 int index = PCI_FUNC(pdev->devfn);
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.
91 mid->dma_index = index;
92 mid->dma_dev = pci_get_slot(pdev->bus, PCI_DEVFN(5, 0));
96 static int dnv_handle_irq(struct uart_port *p)
98 struct mid8250 *mid = p->private_data;
99 unsigned int fisr = serial_port_in(p, INTEL_MID_UART_DNV_FISR);
103 ret |= hsu_dma_irq(&mid->dma_chip, 1);
105 ret |= hsu_dma_irq(&mid->dma_chip, 0);
107 ret |= serial8250_handle_irq(p, serial_port_in(p, UART_IIR));
111 #define DNV_DMA_CHAN_OFFSET 0x80
113 static int dnv_setup(struct mid8250 *mid, struct uart_port *p)
115 struct hsu_dma_chip *chip = &mid->dma_chip;
116 struct pci_dev *pdev = to_pci_dev(p->dev);
117 unsigned int bar = FL_GET_BASE(mid->board->flags);
120 chip->dev = &pdev->dev;
121 chip->irq = pdev->irq;
122 chip->regs = p->membase;
123 chip->length = pci_resource_len(pdev, bar);
124 chip->offset = DNV_DMA_CHAN_OFFSET;
126 /* Falling back to PIO mode if DMA probing fails */
127 ret = hsu_dma_probe(chip);
133 p->handle_irq = dnv_handle_irq;
137 static void dnv_exit(struct mid8250 *mid)
141 hsu_dma_remove(&mid->dma_chip);
144 /*****************************************************************************/
146 static void mid8250_set_termios(struct uart_port *p,
147 struct ktermios *termios,
148 struct ktermios *old)
150 unsigned int baud = tty_termios_baud_rate(termios);
151 struct mid8250 *mid = p->private_data;
152 unsigned short ps = 16;
153 unsigned long fuart = baud * ps;
154 unsigned long w = BIT(24) - 1;
155 unsigned long mul, div;
157 if (mid->board->freq < fuart) {
158 /* Find prescaler value that satisfies Fuart < Fref */
159 if (mid->board->freq > baud)
160 ps = mid->board->freq / baud; /* baud rate too high */
162 ps = 1; /* PLL case */
165 /* Get Fuart closer to Fref */
166 fuart *= rounddown_pow_of_two(mid->board->freq / fuart);
169 rational_best_approximation(fuart, mid->board->freq, w, w, &mul, &div);
170 p->uartclk = fuart * 16 / ps; /* core uses ps = 16 always */
172 writel(ps, p->membase + INTEL_MID_UART_PS); /* set PS */
173 writel(mul, p->membase + INTEL_MID_UART_MUL); /* set MUL */
174 writel(div, p->membase + INTEL_MID_UART_DIV);
176 serial8250_do_set_termios(p, termios, old);
179 static bool mid8250_dma_filter(struct dma_chan *chan, void *param)
181 struct hsu_dma_slave *s = param;
183 if (s->dma_dev != chan->device->dev || s->chan_id != chan->chan_id)
190 static int mid8250_dma_setup(struct mid8250 *mid, struct uart_8250_port *port)
192 struct uart_8250_dma *dma = &mid->dma;
193 struct device *dev = port->port.dev;
194 struct hsu_dma_slave *rx_param;
195 struct hsu_dma_slave *tx_param;
200 rx_param = devm_kzalloc(dev, sizeof(*rx_param), GFP_KERNEL);
204 tx_param = devm_kzalloc(dev, sizeof(*tx_param), GFP_KERNEL);
208 rx_param->chan_id = mid->dma_index * 2 + 1;
209 tx_param->chan_id = mid->dma_index * 2;
211 dma->rxconf.src_maxburst = 64;
212 dma->txconf.dst_maxburst = 64;
214 rx_param->dma_dev = &mid->dma_dev->dev;
215 tx_param->dma_dev = &mid->dma_dev->dev;
217 dma->fn = mid8250_dma_filter;
218 dma->rx_param = rx_param;
219 dma->tx_param = tx_param;
225 static int mid8250_probe(struct pci_dev *pdev, const struct pci_device_id *id)
227 struct uart_8250_port uart;
232 ret = pcim_enable_device(pdev);
236 pci_set_master(pdev);
238 mid = devm_kzalloc(&pdev->dev, sizeof(*mid), GFP_KERNEL);
242 mid->board = (struct mid8250_board *)id->driver_data;
243 bar = FL_GET_BASE(mid->board->flags);
245 memset(&uart, 0, sizeof(struct uart_8250_port));
247 uart.port.dev = &pdev->dev;
248 uart.port.irq = pdev->irq;
249 uart.port.private_data = mid;
250 uart.port.type = PORT_16750;
251 uart.port.iotype = UPIO_MEM;
252 uart.port.uartclk = mid->board->base_baud * 16;
253 uart.port.flags = UPF_SHARE_IRQ | UPF_FIXED_PORT | UPF_FIXED_TYPE;
254 uart.port.set_termios = mid8250_set_termios;
256 uart.port.mapbase = pci_resource_start(pdev, bar);
257 uart.port.membase = pcim_iomap(pdev, bar, 0);
258 if (!uart.port.membase)
261 if (mid->board->setup) {
262 ret = mid->board->setup(mid, &uart.port);
267 ret = mid8250_dma_setup(mid, &uart);
271 ret = serial8250_register_8250_port(&uart);
277 pci_set_drvdata(pdev, mid);
280 if (mid->board->exit)
281 mid->board->exit(mid);
285 static void mid8250_remove(struct pci_dev *pdev)
287 struct mid8250 *mid = pci_get_drvdata(pdev);
289 if (mid->board->exit)
290 mid->board->exit(mid);
292 serial8250_unregister_port(mid->line);
295 static const struct mid8250_board pnw_board = {
302 static const struct mid8250_board tng_board = {
305 .base_baud = 1843200,
309 static const struct mid8250_board dnv_board = {
317 #define MID_DEVICE(id, board) { PCI_VDEVICE(INTEL, id), (kernel_ulong_t)&board }
319 static const struct pci_device_id pci_ids[] = {
320 MID_DEVICE(PCI_DEVICE_ID_INTEL_PNW_UART1, pnw_board),
321 MID_DEVICE(PCI_DEVICE_ID_INTEL_PNW_UART2, pnw_board),
322 MID_DEVICE(PCI_DEVICE_ID_INTEL_PNW_UART3, pnw_board),
323 MID_DEVICE(PCI_DEVICE_ID_INTEL_TNG_UART, tng_board),
324 MID_DEVICE(PCI_DEVICE_ID_INTEL_DNV_UART, dnv_board),
327 MODULE_DEVICE_TABLE(pci, pci_ids);
329 static struct pci_driver mid8250_pci_driver = {
332 .probe = mid8250_probe,
333 .remove = mid8250_remove,
336 module_pci_driver(mid8250_pci_driver);
338 MODULE_AUTHOR("Intel Corporation");
339 MODULE_LICENSE("GPL v2");
340 MODULE_DESCRIPTION("Intel MID UART driver");