1 // SPDX-License-Identifier: GPL-2.0
3 * 8250_mid.c - Driver for UART on Intel Penwell and various other Intel SOCs
5 * Copyright (C) 2015 Intel Corporation
6 * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
9 #include <linux/bitops.h>
10 #include <linux/module.h>
11 #include <linux/pci.h>
12 #include <linux/rational.h>
14 #include <linux/dma/hsu.h>
18 #define PCI_DEVICE_ID_INTEL_PNW_UART1 0x081b
19 #define PCI_DEVICE_ID_INTEL_PNW_UART2 0x081c
20 #define PCI_DEVICE_ID_INTEL_PNW_UART3 0x081d
21 #define PCI_DEVICE_ID_INTEL_TNG_UART 0x1191
22 #define PCI_DEVICE_ID_INTEL_CDF_UART 0x18d8
23 #define PCI_DEVICE_ID_INTEL_DNV_UART 0x19d8
25 /* Intel MID Specific registers */
26 #define INTEL_MID_UART_FISR 0x08
27 #define INTEL_MID_UART_PS 0x30
28 #define INTEL_MID_UART_MUL 0x34
29 #define INTEL_MID_UART_DIV 0x38
33 struct mid8250_board {
35 unsigned int base_baud;
37 int (*setup)(struct mid8250 *, struct uart_port *p);
38 void (*exit)(struct mid8250 *);
44 struct pci_dev *dma_dev;
45 struct uart_8250_dma dma;
46 struct mid8250_board *board;
47 struct hsu_dma_chip dma_chip;
50 /*****************************************************************************/
52 static int pnw_setup(struct mid8250 *mid, struct uart_port *p)
54 struct pci_dev *pdev = to_pci_dev(p->dev);
56 switch (pdev->device) {
57 case PCI_DEVICE_ID_INTEL_PNW_UART1:
60 case PCI_DEVICE_ID_INTEL_PNW_UART2:
63 case PCI_DEVICE_ID_INTEL_PNW_UART3:
70 mid->dma_dev = pci_get_slot(pdev->bus,
71 PCI_DEVFN(PCI_SLOT(pdev->devfn), 3));
75 static void pnw_exit(struct mid8250 *mid)
77 pci_dev_put(mid->dma_dev);
80 static int tng_handle_irq(struct uart_port *p)
82 struct mid8250 *mid = p->private_data;
83 struct uart_8250_port *up = up_to_u8250p(p);
84 struct hsu_dma_chip *chip;
89 chip = pci_get_drvdata(mid->dma_dev);
92 err = hsu_dma_get_status(chip, mid->dma_index * 2 + 1, &status);
94 serial8250_rx_dma_flush(up);
97 ret |= hsu_dma_do_irq(chip, mid->dma_index * 2 + 1, status);
100 err = hsu_dma_get_status(chip, mid->dma_index * 2, &status);
104 ret |= hsu_dma_do_irq(chip, mid->dma_index * 2, status);
107 ret |= serial8250_handle_irq(p, serial_port_in(p, UART_IIR));
108 return IRQ_RETVAL(ret);
111 static int tng_setup(struct mid8250 *mid, struct uart_port *p)
113 struct pci_dev *pdev = to_pci_dev(p->dev);
114 int index = PCI_FUNC(pdev->devfn);
117 * Device 0000:00:04.0 is not a real HSU port. It provides a global
118 * register set for all HSU ports, although it has the same PCI ID.
124 mid->dma_index = index;
125 mid->dma_dev = pci_get_slot(pdev->bus, PCI_DEVFN(5, 0));
127 p->handle_irq = tng_handle_irq;
131 static void tng_exit(struct mid8250 *mid)
133 pci_dev_put(mid->dma_dev);
136 static int dnv_handle_irq(struct uart_port *p)
138 struct mid8250 *mid = p->private_data;
139 struct uart_8250_port *up = up_to_u8250p(p);
140 unsigned int fisr = serial_port_in(p, INTEL_MID_UART_FISR);
146 err = hsu_dma_get_status(&mid->dma_chip, 1, &status);
148 serial8250_rx_dma_flush(up);
151 ret |= hsu_dma_do_irq(&mid->dma_chip, 1, status);
154 err = hsu_dma_get_status(&mid->dma_chip, 0, &status);
158 ret |= hsu_dma_do_irq(&mid->dma_chip, 0, status);
161 ret |= serial8250_handle_irq(p, serial_port_in(p, UART_IIR));
162 return IRQ_RETVAL(ret);
165 #define DNV_DMA_CHAN_OFFSET 0x80
167 static int dnv_setup(struct mid8250 *mid, struct uart_port *p)
169 struct hsu_dma_chip *chip = &mid->dma_chip;
170 struct pci_dev *pdev = to_pci_dev(p->dev);
173 pci_set_master(pdev);
175 ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_ALL_TYPES);
179 p->irq = pci_irq_vector(pdev, 0);
181 chip->dev = &pdev->dev;
182 chip->irq = pci_irq_vector(pdev, 0);
183 chip->regs = p->membase;
184 chip->length = pci_resource_len(pdev, mid->board->bar);
185 chip->offset = DNV_DMA_CHAN_OFFSET;
187 /* Falling back to PIO mode if DMA probing fails */
188 ret = hsu_dma_probe(chip);
194 p->handle_irq = dnv_handle_irq;
198 static void dnv_exit(struct mid8250 *mid)
202 hsu_dma_remove(&mid->dma_chip);
205 /*****************************************************************************/
207 static void mid8250_set_termios(struct uart_port *p, struct ktermios *termios,
208 const struct ktermios *old)
210 unsigned int baud = tty_termios_baud_rate(termios);
211 struct mid8250 *mid = p->private_data;
212 unsigned short ps = 16;
213 unsigned long fuart = baud * ps;
214 unsigned long w = BIT(24) - 1;
215 unsigned long mul, div;
217 /* Gracefully handle the B0 case: fall back to B9600 */
218 fuart = fuart ? fuart : 9600 * 16;
220 if (mid->board->freq < fuart) {
221 /* Find prescaler value that satisfies Fuart < Fref */
222 if (mid->board->freq > baud)
223 ps = mid->board->freq / baud; /* baud rate too high */
225 ps = 1; /* PLL case */
228 /* Get Fuart closer to Fref */
229 fuart *= rounddown_pow_of_two(mid->board->freq / fuart);
232 rational_best_approximation(fuart, mid->board->freq, w, w, &mul, &div);
233 p->uartclk = fuart * 16 / ps; /* core uses ps = 16 always */
235 writel(ps, p->membase + INTEL_MID_UART_PS); /* set PS */
236 writel(mul, p->membase + INTEL_MID_UART_MUL); /* set MUL */
237 writel(div, p->membase + INTEL_MID_UART_DIV);
239 serial8250_do_set_termios(p, termios, old);
242 static bool mid8250_dma_filter(struct dma_chan *chan, void *param)
244 struct hsu_dma_slave *s = param;
246 if (s->dma_dev != chan->device->dev || s->chan_id != chan->chan_id)
253 static int mid8250_dma_setup(struct mid8250 *mid, struct uart_8250_port *port)
255 struct uart_8250_dma *dma = &mid->dma;
256 struct device *dev = port->port.dev;
257 struct hsu_dma_slave *rx_param;
258 struct hsu_dma_slave *tx_param;
263 rx_param = devm_kzalloc(dev, sizeof(*rx_param), GFP_KERNEL);
267 tx_param = devm_kzalloc(dev, sizeof(*tx_param), GFP_KERNEL);
271 rx_param->chan_id = mid->dma_index * 2 + 1;
272 tx_param->chan_id = mid->dma_index * 2;
274 dma->rxconf.src_maxburst = 64;
275 dma->txconf.dst_maxburst = 64;
277 rx_param->dma_dev = &mid->dma_dev->dev;
278 tx_param->dma_dev = &mid->dma_dev->dev;
280 dma->fn = mid8250_dma_filter;
281 dma->rx_param = rx_param;
282 dma->tx_param = tx_param;
288 static int mid8250_probe(struct pci_dev *pdev, const struct pci_device_id *id)
290 struct uart_8250_port uart;
294 ret = pcim_enable_device(pdev);
298 mid = devm_kzalloc(&pdev->dev, sizeof(*mid), GFP_KERNEL);
302 mid->board = (struct mid8250_board *)id->driver_data;
304 memset(&uart, 0, sizeof(struct uart_8250_port));
306 uart.port.dev = &pdev->dev;
307 uart.port.irq = pdev->irq;
308 uart.port.private_data = mid;
309 uart.port.type = PORT_16750;
310 uart.port.iotype = UPIO_MEM;
311 uart.port.uartclk = mid->board->base_baud * 16;
312 uart.port.flags = UPF_SHARE_IRQ | UPF_FIXED_PORT | UPF_FIXED_TYPE;
313 uart.port.set_termios = mid8250_set_termios;
315 uart.port.mapbase = pci_resource_start(pdev, mid->board->bar);
316 uart.port.membase = pcim_iomap(pdev, mid->board->bar, 0);
317 if (!uart.port.membase)
320 ret = mid->board->setup(mid, &uart.port);
324 ret = mid8250_dma_setup(mid, &uart);
328 ret = serial8250_register_8250_port(&uart);
334 pci_set_drvdata(pdev, mid);
338 mid->board->exit(mid);
342 static void mid8250_remove(struct pci_dev *pdev)
344 struct mid8250 *mid = pci_get_drvdata(pdev);
346 serial8250_unregister_port(mid->line);
348 mid->board->exit(mid);
351 static const struct mid8250_board pnw_board = {
359 static const struct mid8250_board tng_board = {
361 .base_baud = 1843200,
367 static const struct mid8250_board dnv_board = {
375 static const struct pci_device_id pci_ids[] = {
376 { PCI_DEVICE_DATA(INTEL, PNW_UART1, &pnw_board) },
377 { PCI_DEVICE_DATA(INTEL, PNW_UART2, &pnw_board) },
378 { PCI_DEVICE_DATA(INTEL, PNW_UART3, &pnw_board) },
379 { PCI_DEVICE_DATA(INTEL, TNG_UART, &tng_board) },
380 { PCI_DEVICE_DATA(INTEL, CDF_UART, &dnv_board) },
381 { PCI_DEVICE_DATA(INTEL, DNV_UART, &dnv_board) },
384 MODULE_DEVICE_TABLE(pci, pci_ids);
386 static struct pci_driver mid8250_pci_driver = {
389 .probe = mid8250_probe,
390 .remove = mid8250_remove,
393 module_pci_driver(mid8250_pci_driver);
395 MODULE_AUTHOR("Intel Corporation");
396 MODULE_LICENSE("GPL v2");
397 MODULE_DESCRIPTION("Intel MID UART driver");