Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/arch/arm/mach-pxa/ssp.c |
| 3 | * |
| 4 | * based on linux/arch/arm/mach-sa1100/ssp.c by Russell King |
| 5 | * |
| 6 | * Copyright (C) 2003 Russell King. |
| 7 | * Copyright (C) 2003 Wolfson Microelectronics PLC |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify |
| 10 | * it under the terms of the GNU General Public License version 2 as |
| 11 | * published by the Free Software Foundation. |
| 12 | * |
| 13 | * PXA2xx SSP driver. This provides the generic core for simple |
| 14 | * IO-based SSP applications and allows easy port setup for DMA access. |
| 15 | * |
| 16 | * Author: Liam Girdwood <liam.girdwood@wolfsonmicro.com> |
| 17 | * |
| 18 | * Revision history: |
| 19 | * 22nd Aug 2003 Initial version. |
| 20 | * 20th Dec 2004 Added ssp_config for changing port config without |
| 21 | * closing the port. |
Liam Girdwood | b216c01 | 2005-11-10 17:45:39 +0000 | [diff] [blame] | 22 | * 4th Aug 2005 Added option to disable irq handler registration and |
| 23 | * cleaned up irq and clock detection. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | */ |
| 25 | |
| 26 | #include <linux/module.h> |
| 27 | #include <linux/kernel.h> |
| 28 | #include <linux/sched.h> |
| 29 | #include <linux/slab.h> |
| 30 | #include <linux/errno.h> |
| 31 | #include <linux/interrupt.h> |
| 32 | #include <linux/ioport.h> |
| 33 | #include <linux/init.h> |
Arjan van de Ven | 0043170 | 2006-01-12 18:42:23 +0000 | [diff] [blame] | 34 | #include <linux/mutex.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | #include <asm/io.h> |
| 36 | #include <asm/irq.h> |
| 37 | #include <asm/hardware.h> |
| 38 | #include <asm/arch/ssp.h> |
| 39 | #include <asm/arch/pxa-regs.h> |
| 40 | |
| 41 | #define PXA_SSP_PORTS 3 |
| 42 | |
Paul Sokolovsky | 8f1bf87 | 2006-08-27 12:54:56 +0100 | [diff] [blame^] | 43 | #define TIMEOUT 100000 |
| 44 | |
Liam Girdwood | b216c01 | 2005-11-10 17:45:39 +0000 | [diff] [blame] | 45 | struct ssp_info_ { |
| 46 | int irq; |
| 47 | u32 clock; |
| 48 | }; |
| 49 | |
| 50 | /* |
| 51 | * SSP port clock and IRQ settings |
| 52 | */ |
| 53 | static const struct ssp_info_ ssp_info[PXA_SSP_PORTS] = { |
| 54 | #if defined (CONFIG_PXA27x) |
| 55 | {IRQ_SSP, CKEN23_SSP1}, |
| 56 | {IRQ_SSP2, CKEN3_SSP2}, |
| 57 | {IRQ_SSP3, CKEN4_SSP3}, |
| 58 | #else |
| 59 | {IRQ_SSP, CKEN3_SSP}, |
| 60 | {IRQ_NSSP, CKEN9_NSSP}, |
| 61 | {IRQ_ASSP, CKEN10_ASSP}, |
| 62 | #endif |
| 63 | }; |
| 64 | |
Arjan van de Ven | 0043170 | 2006-01-12 18:42:23 +0000 | [diff] [blame] | 65 | static DEFINE_MUTEX(mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 66 | static int use_count[PXA_SSP_PORTS] = {0, 0, 0}; |
| 67 | |
| 68 | static irqreturn_t ssp_interrupt(int irq, void *dev_id, struct pt_regs *regs) |
| 69 | { |
| 70 | struct ssp_dev *dev = (struct ssp_dev*) dev_id; |
| 71 | unsigned int status = SSSR_P(dev->port); |
| 72 | |
| 73 | SSSR_P(dev->port) = status; /* clear status bits */ |
| 74 | |
| 75 | if (status & SSSR_ROR) |
| 76 | printk(KERN_WARNING "SSP(%d): receiver overrun\n", dev->port); |
| 77 | |
| 78 | if (status & SSSR_TUR) |
| 79 | printk(KERN_WARNING "SSP(%d): transmitter underrun\n", dev->port); |
| 80 | |
| 81 | if (status & SSSR_BCE) |
| 82 | printk(KERN_WARNING "SSP(%d): bit count error\n", dev->port); |
| 83 | |
| 84 | return IRQ_HANDLED; |
| 85 | } |
| 86 | |
| 87 | /** |
| 88 | * ssp_write_word - write a word to the SSP port |
| 89 | * @data: 32-bit, MSB justified data to write. |
| 90 | * |
| 91 | * Wait for a free entry in the SSP transmit FIFO, and write a data |
| 92 | * word to the SSP port. |
| 93 | * |
| 94 | * The caller is expected to perform the necessary locking. |
| 95 | * |
| 96 | * Returns: |
Paul Sokolovsky | 8f1bf87 | 2006-08-27 12:54:56 +0100 | [diff] [blame^] | 97 | * %-ETIMEDOUT timeout occurred |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 98 | * 0 success |
| 99 | */ |
| 100 | int ssp_write_word(struct ssp_dev *dev, u32 data) |
| 101 | { |
Paul Sokolovsky | 8f1bf87 | 2006-08-27 12:54:56 +0100 | [diff] [blame^] | 102 | int timeout = TIMEOUT; |
| 103 | |
| 104 | while (!(SSSR_P(dev->port) & SSSR_TNF)) { |
| 105 | if (!--timeout) |
| 106 | return -ETIMEDOUT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 107 | cpu_relax(); |
Paul Sokolovsky | 8f1bf87 | 2006-08-27 12:54:56 +0100 | [diff] [blame^] | 108 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | |
| 110 | SSDR_P(dev->port) = data; |
| 111 | |
| 112 | return 0; |
| 113 | } |
| 114 | |
| 115 | /** |
| 116 | * ssp_read_word - read a word from the SSP port |
| 117 | * |
| 118 | * Wait for a data word in the SSP receive FIFO, and return the |
| 119 | * received data. Data is LSB justified. |
| 120 | * |
| 121 | * Note: Currently, if data is not expected to be received, this |
| 122 | * function will wait for ever. |
| 123 | * |
| 124 | * The caller is expected to perform the necessary locking. |
| 125 | * |
| 126 | * Returns: |
Paul Sokolovsky | 8f1bf87 | 2006-08-27 12:54:56 +0100 | [diff] [blame^] | 127 | * %-ETIMEDOUT timeout occurred |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 128 | * 32-bit data success |
| 129 | */ |
Paul Sokolovsky | 8f1bf87 | 2006-08-27 12:54:56 +0100 | [diff] [blame^] | 130 | int ssp_read_word(struct ssp_dev *dev, u32 *data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 131 | { |
Paul Sokolovsky | 8f1bf87 | 2006-08-27 12:54:56 +0100 | [diff] [blame^] | 132 | int timeout = TIMEOUT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | |
Paul Sokolovsky | 8f1bf87 | 2006-08-27 12:54:56 +0100 | [diff] [blame^] | 134 | while (!(SSSR_P(dev->port) & SSSR_RNE)) { |
| 135 | if (!--timeout) |
| 136 | return -ETIMEDOUT; |
| 137 | cpu_relax(); |
| 138 | } |
| 139 | |
| 140 | *data = SSDR_P(dev->port); |
| 141 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 142 | } |
| 143 | |
| 144 | /** |
| 145 | * ssp_flush - flush the transmit and receive FIFOs |
| 146 | * |
| 147 | * Wait for the SSP to idle, and ensure that the receive FIFO |
| 148 | * is empty. |
| 149 | * |
| 150 | * The caller is expected to perform the necessary locking. |
| 151 | */ |
Paul Sokolovsky | 8f1bf87 | 2006-08-27 12:54:56 +0100 | [diff] [blame^] | 152 | int ssp_flush(struct ssp_dev *dev) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 153 | { |
Paul Sokolovsky | 8f1bf87 | 2006-08-27 12:54:56 +0100 | [diff] [blame^] | 154 | int timeout = TIMEOUT * 2; |
| 155 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | do { |
| 157 | while (SSSR_P(dev->port) & SSSR_RNE) { |
Paul Sokolovsky | 8f1bf87 | 2006-08-27 12:54:56 +0100 | [diff] [blame^] | 158 | if (!--timeout) |
| 159 | return -ETIMEDOUT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 160 | (void) SSDR_P(dev->port); |
| 161 | } |
Paul Sokolovsky | 8f1bf87 | 2006-08-27 12:54:56 +0100 | [diff] [blame^] | 162 | if (!--timeout) |
| 163 | return -ETIMEDOUT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 164 | } while (SSSR_P(dev->port) & SSSR_BSY); |
Paul Sokolovsky | 8f1bf87 | 2006-08-27 12:54:56 +0100 | [diff] [blame^] | 165 | |
| 166 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 167 | } |
| 168 | |
| 169 | /** |
| 170 | * ssp_enable - enable the SSP port |
| 171 | * |
| 172 | * Turn on the SSP port. |
| 173 | */ |
| 174 | void ssp_enable(struct ssp_dev *dev) |
| 175 | { |
| 176 | SSCR0_P(dev->port) |= SSCR0_SSE; |
| 177 | } |
| 178 | |
| 179 | /** |
| 180 | * ssp_disable - shut down the SSP port |
| 181 | * |
| 182 | * Turn off the SSP port, optionally powering it down. |
| 183 | */ |
| 184 | void ssp_disable(struct ssp_dev *dev) |
| 185 | { |
| 186 | SSCR0_P(dev->port) &= ~SSCR0_SSE; |
| 187 | } |
| 188 | |
| 189 | /** |
| 190 | * ssp_save_state - save the SSP configuration |
| 191 | * @ssp: pointer to structure to save SSP configuration |
| 192 | * |
| 193 | * Save the configured SSP state for suspend. |
| 194 | */ |
| 195 | void ssp_save_state(struct ssp_dev *dev, struct ssp_state *ssp) |
| 196 | { |
| 197 | ssp->cr0 = SSCR0_P(dev->port); |
| 198 | ssp->cr1 = SSCR1_P(dev->port); |
| 199 | ssp->to = SSTO_P(dev->port); |
| 200 | ssp->psp = SSPSP_P(dev->port); |
| 201 | |
| 202 | SSCR0_P(dev->port) &= ~SSCR0_SSE; |
| 203 | } |
| 204 | |
| 205 | /** |
| 206 | * ssp_restore_state - restore a previously saved SSP configuration |
| 207 | * @ssp: pointer to configuration saved by ssp_save_state |
| 208 | * |
| 209 | * Restore the SSP configuration saved previously by ssp_save_state. |
| 210 | */ |
| 211 | void ssp_restore_state(struct ssp_dev *dev, struct ssp_state *ssp) |
| 212 | { |
| 213 | SSSR_P(dev->port) = SSSR_ROR | SSSR_TUR | SSSR_BCE; |
| 214 | |
| 215 | SSCR0_P(dev->port) = ssp->cr0 & ~SSCR0_SSE; |
| 216 | SSCR1_P(dev->port) = ssp->cr1; |
| 217 | SSTO_P(dev->port) = ssp->to; |
| 218 | SSPSP_P(dev->port) = ssp->psp; |
| 219 | |
| 220 | SSCR0_P(dev->port) = ssp->cr0; |
| 221 | } |
| 222 | |
| 223 | /** |
| 224 | * ssp_config - configure SSP port settings |
| 225 | * @mode: port operating mode |
| 226 | * @flags: port config flags |
| 227 | * @psp_flags: port PSP config flags |
| 228 | * @speed: port speed |
| 229 | * |
| 230 | * Port MUST be disabled by ssp_disable before making any config changes. |
| 231 | */ |
| 232 | int ssp_config(struct ssp_dev *dev, u32 mode, u32 flags, u32 psp_flags, u32 speed) |
| 233 | { |
| 234 | dev->mode = mode; |
| 235 | dev->flags = flags; |
| 236 | dev->psp_flags = psp_flags; |
| 237 | dev->speed = speed; |
| 238 | |
| 239 | /* set up port type, speed, port settings */ |
| 240 | SSCR0_P(dev->port) = (dev->speed | dev->mode); |
| 241 | SSCR1_P(dev->port) = dev->flags; |
| 242 | SSPSP_P(dev->port) = dev->psp_flags; |
| 243 | |
| 244 | return 0; |
| 245 | } |
| 246 | |
| 247 | /** |
| 248 | * ssp_init - setup the SSP port |
| 249 | * |
| 250 | * initialise and claim resources for the SSP port. |
| 251 | * |
| 252 | * Returns: |
| 253 | * %-ENODEV if the SSP port is unavailable |
| 254 | * %-EBUSY if the resources are already in use |
| 255 | * %0 on success |
| 256 | */ |
Liam Girdwood | b216c01 | 2005-11-10 17:45:39 +0000 | [diff] [blame] | 257 | int ssp_init(struct ssp_dev *dev, u32 port, u32 init_flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 258 | { |
Liam Girdwood | b216c01 | 2005-11-10 17:45:39 +0000 | [diff] [blame] | 259 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 260 | |
| 261 | if (port > PXA_SSP_PORTS || port == 0) |
| 262 | return -ENODEV; |
| 263 | |
Arjan van de Ven | 0043170 | 2006-01-12 18:42:23 +0000 | [diff] [blame] | 264 | mutex_lock(&mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 265 | if (use_count[port - 1]) { |
Arjan van de Ven | 0043170 | 2006-01-12 18:42:23 +0000 | [diff] [blame] | 266 | mutex_unlock(&mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 267 | return -EBUSY; |
| 268 | } |
| 269 | use_count[port - 1]++; |
| 270 | |
| 271 | if (!request_mem_region(__PREG(SSCR0_P(port)), 0x2c, "SSP")) { |
| 272 | use_count[port - 1]--; |
Arjan van de Ven | 0043170 | 2006-01-12 18:42:23 +0000 | [diff] [blame] | 273 | mutex_unlock(&mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 274 | return -EBUSY; |
| 275 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 276 | dev->port = port; |
| 277 | |
Liam Girdwood | b216c01 | 2005-11-10 17:45:39 +0000 | [diff] [blame] | 278 | /* do we need to get irq */ |
| 279 | if (!(init_flags & SSP_NO_IRQ)) { |
| 280 | ret = request_irq(ssp_info[port-1].irq, ssp_interrupt, |
| 281 | 0, "SSP", dev); |
| 282 | if (ret) |
| 283 | goto out_region; |
| 284 | dev->irq = ssp_info[port-1].irq; |
| 285 | } else |
| 286 | dev->irq = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 287 | |
| 288 | /* turn on SSP port clock */ |
Liam Girdwood | b216c01 | 2005-11-10 17:45:39 +0000 | [diff] [blame] | 289 | pxa_set_cken(ssp_info[port-1].clock, 1); |
Arjan van de Ven | 0043170 | 2006-01-12 18:42:23 +0000 | [diff] [blame] | 290 | mutex_unlock(&mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 291 | return 0; |
| 292 | |
| 293 | out_region: |
| 294 | release_mem_region(__PREG(SSCR0_P(port)), 0x2c); |
| 295 | use_count[port - 1]--; |
Arjan van de Ven | 0043170 | 2006-01-12 18:42:23 +0000 | [diff] [blame] | 296 | mutex_unlock(&mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 297 | return ret; |
| 298 | } |
| 299 | |
| 300 | /** |
| 301 | * ssp_exit - undo the effects of ssp_init |
| 302 | * |
| 303 | * release and free resources for the SSP port. |
| 304 | */ |
| 305 | void ssp_exit(struct ssp_dev *dev) |
| 306 | { |
Arjan van de Ven | 0043170 | 2006-01-12 18:42:23 +0000 | [diff] [blame] | 307 | mutex_lock(&mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 308 | SSCR0_P(dev->port) &= ~SSCR0_SSE; |
| 309 | |
Liam Girdwood | b216c01 | 2005-11-10 17:45:39 +0000 | [diff] [blame] | 310 | if (dev->port > PXA_SSP_PORTS || dev->port == 0) { |
| 311 | printk(KERN_WARNING "SSP: tried to close invalid port\n"); |
| 312 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 313 | } |
| 314 | |
Liam Girdwood | b216c01 | 2005-11-10 17:45:39 +0000 | [diff] [blame] | 315 | pxa_set_cken(ssp_info[dev->port-1].clock, 0); |
| 316 | if (dev->irq) |
| 317 | free_irq(dev->irq, dev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 318 | release_mem_region(__PREG(SSCR0_P(dev->port)), 0x2c); |
| 319 | use_count[dev->port - 1]--; |
Arjan van de Ven | 0043170 | 2006-01-12 18:42:23 +0000 | [diff] [blame] | 320 | mutex_unlock(&mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 321 | } |
| 322 | |
| 323 | EXPORT_SYMBOL(ssp_write_word); |
| 324 | EXPORT_SYMBOL(ssp_read_word); |
| 325 | EXPORT_SYMBOL(ssp_flush); |
| 326 | EXPORT_SYMBOL(ssp_enable); |
| 327 | EXPORT_SYMBOL(ssp_disable); |
| 328 | EXPORT_SYMBOL(ssp_save_state); |
| 329 | EXPORT_SYMBOL(ssp_restore_state); |
| 330 | EXPORT_SYMBOL(ssp_init); |
| 331 | EXPORT_SYMBOL(ssp_exit); |
| 332 | EXPORT_SYMBOL(ssp_config); |
| 333 | |
| 334 | MODULE_DESCRIPTION("PXA SSP driver"); |
| 335 | MODULE_AUTHOR("Liam Girdwood"); |
| 336 | MODULE_LICENSE("GPL"); |
| 337 | |