1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * 8250_mid.c - Driver for UART on Intel Penwell and various other Intel SOCs 4 * 5 * Copyright (C) 2015 Intel Corporation 6 * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com> 7 */ 8 9 #include <linux/bitops.h> 10 #include <linux/module.h> 11 #include <linux/pci.h> 12 #include <linux/rational.h> 13 14 #include <linux/dma/hsu.h> 15 #include <linux/8250_pci.h> 16 17 #include "8250.h" 18 19 #define PCI_DEVICE_ID_INTEL_PNW_UART1 0x081b 20 #define PCI_DEVICE_ID_INTEL_PNW_UART2 0x081c 21 #define PCI_DEVICE_ID_INTEL_PNW_UART3 0x081d 22 #define PCI_DEVICE_ID_INTEL_TNG_UART 0x1191 23 #define PCI_DEVICE_ID_INTEL_CDF_UART 0x18d8 24 #define PCI_DEVICE_ID_INTEL_DNV_UART 0x19d8 25 26 /* Intel MID Specific registers */ 27 #define INTEL_MID_UART_FISR 0x08 28 #define INTEL_MID_UART_PS 0x30 29 #define INTEL_MID_UART_MUL 0x34 30 #define INTEL_MID_UART_DIV 0x38 31 32 struct mid8250; 33 34 struct mid8250_board { 35 unsigned int flags; 36 unsigned long freq; 37 unsigned int base_baud; 38 int (*setup)(struct mid8250 *, struct uart_port *p); 39 void (*exit)(struct mid8250 *); 40 }; 41 42 struct mid8250 { 43 int line; 44 int dma_index; 45 struct pci_dev *dma_dev; 46 struct uart_8250_dma dma; 47 struct mid8250_board *board; 48 struct hsu_dma_chip dma_chip; 49 }; 50 51 /*****************************************************************************/ 52 53 static int pnw_setup(struct mid8250 *mid, struct uart_port *p) 54 { 55 struct pci_dev *pdev = to_pci_dev(p->dev); 56 57 switch (pdev->device) { 58 case PCI_DEVICE_ID_INTEL_PNW_UART1: 59 mid->dma_index = 0; 60 break; 61 case PCI_DEVICE_ID_INTEL_PNW_UART2: 62 mid->dma_index = 1; 63 break; 64 case PCI_DEVICE_ID_INTEL_PNW_UART3: 65 mid->dma_index = 2; 66 break; 67 default: 68 return -EINVAL; 69 } 70 71 mid->dma_dev = pci_get_slot(pdev->bus, 72 PCI_DEVFN(PCI_SLOT(pdev->devfn), 3)); 73 return 0; 74 } 75 76 static int tng_handle_irq(struct uart_port *p) 77 { 78 struct mid8250 *mid = p->private_data; 79 struct uart_8250_port *up = up_to_u8250p(p); 80 struct hsu_dma_chip *chip; 81 u32 status; 82 int ret = 0; 83 int err; 84 85 chip = pci_get_drvdata(mid->dma_dev); 86 87 /* Rx DMA */ 88 err = hsu_dma_get_status(chip, mid->dma_index * 2 + 1, &status); 89 if (err > 0) { 90 serial8250_rx_dma_flush(up); 91 ret |= 1; 92 } else if (err == 0) 93 ret |= hsu_dma_do_irq(chip, mid->dma_index * 2 + 1, status); 94 95 /* Tx DMA */ 96 err = hsu_dma_get_status(chip, mid->dma_index * 2, &status); 97 if (err > 0) 98 ret |= 1; 99 else if (err == 0) 100 ret |= hsu_dma_do_irq(chip, mid->dma_index * 2, status); 101 102 /* UART */ 103 ret |= serial8250_handle_irq(p, serial_port_in(p, UART_IIR)); 104 return IRQ_RETVAL(ret); 105 } 106 107 static int tng_setup(struct mid8250 *mid, struct uart_port *p) 108 { 109 struct pci_dev *pdev = to_pci_dev(p->dev); 110 int index = PCI_FUNC(pdev->devfn); 111 112 /* 113 * Device 0000:00:04.0 is not a real HSU port. It provides a global 114 * register set for all HSU ports, although it has the same PCI ID. 115 * Skip it here. 116 */ 117 if (index-- == 0) 118 return -ENODEV; 119 120 mid->dma_index = index; 121 mid->dma_dev = pci_get_slot(pdev->bus, PCI_DEVFN(5, 0)); 122 123 p->handle_irq = tng_handle_irq; 124 return 0; 125 } 126 127 static int dnv_handle_irq(struct uart_port *p) 128 { 129 struct mid8250 *mid = p->private_data; 130 struct uart_8250_port *up = up_to_u8250p(p); 131 unsigned int fisr = serial_port_in(p, INTEL_MID_UART_FISR); 132 u32 status; 133 int ret = 0; 134 int err; 135 136 if (fisr & BIT(2)) { 137 err = hsu_dma_get_status(&mid->dma_chip, 1, &status); 138 if (err > 0) { 139 serial8250_rx_dma_flush(up); 140 ret |= 1; 141 } else if (err == 0) 142 ret |= hsu_dma_do_irq(&mid->dma_chip, 1, status); 143 } 144 if (fisr & BIT(1)) { 145 err = hsu_dma_get_status(&mid->dma_chip, 0, &status); 146 if (err > 0) 147 ret |= 1; 148 else if (err == 0) 149 ret |= hsu_dma_do_irq(&mid->dma_chip, 0, status); 150 } 151 if (fisr & BIT(0)) 152 ret |= serial8250_handle_irq(p, serial_port_in(p, UART_IIR)); 153 return IRQ_RETVAL(ret); 154 } 155 156 #define DNV_DMA_CHAN_OFFSET 0x80 157 158 static int dnv_setup(struct mid8250 *mid, struct uart_port *p) 159 { 160 struct hsu_dma_chip *chip = &mid->dma_chip; 161 struct pci_dev *pdev = to_pci_dev(p->dev); 162 unsigned int bar = FL_GET_BASE(mid->board->flags); 163 int ret; 164 165 pci_set_master(pdev); 166 167 ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_ALL_TYPES); 168 if (ret < 0) 169 return ret; 170 171 p->irq = pci_irq_vector(pdev, 0); 172 173 chip->dev = &pdev->dev; 174 chip->irq = pci_irq_vector(pdev, 0); 175 chip->regs = p->membase; 176 chip->length = pci_resource_len(pdev, bar); 177 chip->offset = DNV_DMA_CHAN_OFFSET; 178 179 /* Falling back to PIO mode if DMA probing fails */ 180 ret = hsu_dma_probe(chip); 181 if (ret) 182 return 0; 183 184 mid->dma_dev = pdev; 185 186 p->handle_irq = dnv_handle_irq; 187 return 0; 188 } 189 190 static void dnv_exit(struct mid8250 *mid) 191 { 192 if (!mid->dma_dev) 193 return; 194 hsu_dma_remove(&mid->dma_chip); 195 } 196 197 /*****************************************************************************/ 198 199 static void mid8250_set_termios(struct uart_port *p, 200 struct ktermios *termios, 201 struct ktermios *old) 202 { 203 unsigned int baud = tty_termios_baud_rate(termios); 204 struct mid8250 *mid = p->private_data; 205 unsigned short ps = 16; 206 unsigned long fuart = baud * ps; 207 unsigned long w = BIT(24) - 1; 208 unsigned long mul, div; 209 210 /* Gracefully handle the B0 case: fall back to B9600 */ 211 fuart = fuart ? fuart : 9600 * 16; 212 213 if (mid->board->freq < fuart) { 214 /* Find prescaler value that satisfies Fuart < Fref */ 215 if (mid->board->freq > baud) 216 ps = mid->board->freq / baud; /* baud rate too high */ 217 else 218 ps = 1; /* PLL case */ 219 fuart = baud * ps; 220 } else { 221 /* Get Fuart closer to Fref */ 222 fuart *= rounddown_pow_of_two(mid->board->freq / fuart); 223 } 224 225 rational_best_approximation(fuart, mid->board->freq, w, w, &mul, &div); 226 p->uartclk = fuart * 16 / ps; /* core uses ps = 16 always */ 227 228 writel(ps, p->membase + INTEL_MID_UART_PS); /* set PS */ 229 writel(mul, p->membase + INTEL_MID_UART_MUL); /* set MUL */ 230 writel(div, p->membase + INTEL_MID_UART_DIV); 231 232 serial8250_do_set_termios(p, termios, old); 233 } 234 235 static bool mid8250_dma_filter(struct dma_chan *chan, void *param) 236 { 237 struct hsu_dma_slave *s = param; 238 239 if (s->dma_dev != chan->device->dev || s->chan_id != chan->chan_id) 240 return false; 241 242 chan->private = s; 243 return true; 244 } 245 246 static int mid8250_dma_setup(struct mid8250 *mid, struct uart_8250_port *port) 247 { 248 struct uart_8250_dma *dma = &mid->dma; 249 struct device *dev = port->port.dev; 250 struct hsu_dma_slave *rx_param; 251 struct hsu_dma_slave *tx_param; 252 253 if (!mid->dma_dev) 254 return 0; 255 256 rx_param = devm_kzalloc(dev, sizeof(*rx_param), GFP_KERNEL); 257 if (!rx_param) 258 return -ENOMEM; 259 260 tx_param = devm_kzalloc(dev, sizeof(*tx_param), GFP_KERNEL); 261 if (!tx_param) 262 return -ENOMEM; 263 264 rx_param->chan_id = mid->dma_index * 2 + 1; 265 tx_param->chan_id = mid->dma_index * 2; 266 267 dma->rxconf.src_maxburst = 64; 268 dma->txconf.dst_maxburst = 64; 269 270 rx_param->dma_dev = &mid->dma_dev->dev; 271 tx_param->dma_dev = &mid->dma_dev->dev; 272 273 dma->fn = mid8250_dma_filter; 274 dma->rx_param = rx_param; 275 dma->tx_param = tx_param; 276 277 port->dma = dma; 278 return 0; 279 } 280 281 static int mid8250_probe(struct pci_dev *pdev, const struct pci_device_id *id) 282 { 283 struct uart_8250_port uart; 284 struct mid8250 *mid; 285 unsigned int bar; 286 int ret; 287 288 ret = pcim_enable_device(pdev); 289 if (ret) 290 return ret; 291 292 mid = devm_kzalloc(&pdev->dev, sizeof(*mid), GFP_KERNEL); 293 if (!mid) 294 return -ENOMEM; 295 296 mid->board = (struct mid8250_board *)id->driver_data; 297 bar = FL_GET_BASE(mid->board->flags); 298 299 memset(&uart, 0, sizeof(struct uart_8250_port)); 300 301 uart.port.dev = &pdev->dev; 302 uart.port.irq = pdev->irq; 303 uart.port.private_data = mid; 304 uart.port.type = PORT_16750; 305 uart.port.iotype = UPIO_MEM; 306 uart.port.uartclk = mid->board->base_baud * 16; 307 uart.port.flags = UPF_SHARE_IRQ | UPF_FIXED_PORT | UPF_FIXED_TYPE; 308 uart.port.set_termios = mid8250_set_termios; 309 310 uart.port.mapbase = pci_resource_start(pdev, bar); 311 uart.port.membase = pcim_iomap(pdev, bar, 0); 312 if (!uart.port.membase) 313 return -ENOMEM; 314 315 if (mid->board->setup) { 316 ret = mid->board->setup(mid, &uart.port); 317 if (ret) 318 return ret; 319 } 320 321 ret = mid8250_dma_setup(mid, &uart); 322 if (ret) 323 goto err; 324 325 ret = serial8250_register_8250_port(&uart); 326 if (ret < 0) 327 goto err; 328 329 mid->line = ret; 330 331 pci_set_drvdata(pdev, mid); 332 return 0; 333 err: 334 if (mid->board->exit) 335 mid->board->exit(mid); 336 return ret; 337 } 338 339 static void mid8250_remove(struct pci_dev *pdev) 340 { 341 struct mid8250 *mid = pci_get_drvdata(pdev); 342 343 serial8250_unregister_port(mid->line); 344 345 if (mid->board->exit) 346 mid->board->exit(mid); 347 } 348 349 static const struct mid8250_board pnw_board = { 350 .flags = FL_BASE0, 351 .freq = 50000000, 352 .base_baud = 115200, 353 .setup = pnw_setup, 354 }; 355 356 static const struct mid8250_board tng_board = { 357 .flags = FL_BASE0, 358 .freq = 38400000, 359 .base_baud = 1843200, 360 .setup = tng_setup, 361 }; 362 363 static const struct mid8250_board dnv_board = { 364 .flags = FL_BASE1, 365 .freq = 133333333, 366 .base_baud = 115200, 367 .setup = dnv_setup, 368 .exit = dnv_exit, 369 }; 370 371 #define MID_DEVICE(id, board) { PCI_VDEVICE(INTEL, id), (kernel_ulong_t)&board } 372 373 static const struct pci_device_id pci_ids[] = { 374 MID_DEVICE(PCI_DEVICE_ID_INTEL_PNW_UART1, pnw_board), 375 MID_DEVICE(PCI_DEVICE_ID_INTEL_PNW_UART2, pnw_board), 376 MID_DEVICE(PCI_DEVICE_ID_INTEL_PNW_UART3, pnw_board), 377 MID_DEVICE(PCI_DEVICE_ID_INTEL_TNG_UART, tng_board), 378 MID_DEVICE(PCI_DEVICE_ID_INTEL_CDF_UART, dnv_board), 379 MID_DEVICE(PCI_DEVICE_ID_INTEL_DNV_UART, dnv_board), 380 { }, 381 }; 382 MODULE_DEVICE_TABLE(pci, pci_ids); 383 384 static struct pci_driver mid8250_pci_driver = { 385 .name = "8250_mid", 386 .id_table = pci_ids, 387 .probe = mid8250_probe, 388 .remove = mid8250_remove, 389 }; 390 391 module_pci_driver(mid8250_pci_driver); 392 393 MODULE_AUTHOR("Intel Corporation"); 394 MODULE_LICENSE("GPL v2"); 395 MODULE_DESCRIPTION("Intel MID UART driver"); 396