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1// SPDX-License-Identifier: GPL-2.0-only2/* bbc_i2c.c: I2C low-level driver for BBC device on UltraSPARC-III3 * platforms.4 *5 * Copyright (C) 2001, 2008 David S. Miller (davem@davemloft.net)6 */7 8#include <linux/module.h>9#include <linux/kernel.h>10#include <linux/types.h>11#include <linux/slab.h>12#include <linux/sched.h>13#include <linux/wait.h>14#include <linux/delay.h>15#include <linux/interrupt.h>16#include <linux/of.h>17#include <linux/of_platform.h>18#include <linux/platform_device.h>19#include <asm/bbc.h>20#include <asm/io.h>21 22#include "bbc_i2c.h"23 24/* Convert this driver to use i2c bus layer someday... */25#define I2C_PCF_PIN 0x8026#define I2C_PCF_ESO 0x4027#define I2C_PCF_ES1 0x2028#define I2C_PCF_ES2 0x1029#define I2C_PCF_ENI 0x0830#define I2C_PCF_STA 0x0431#define I2C_PCF_STO 0x0232#define I2C_PCF_ACK 0x0133 34#define I2C_PCF_START (I2C_PCF_PIN | I2C_PCF_ESO | I2C_PCF_ENI | I2C_PCF_STA | I2C_PCF_ACK)35#define I2C_PCF_STOP (I2C_PCF_PIN | I2C_PCF_ESO | I2C_PCF_STO | I2C_PCF_ACK)36#define I2C_PCF_REPSTART ( I2C_PCF_ESO | I2C_PCF_STA | I2C_PCF_ACK)37#define I2C_PCF_IDLE (I2C_PCF_PIN | I2C_PCF_ESO | I2C_PCF_ACK)38 39#define I2C_PCF_INI 0x40 /* 1 if not initialized */40#define I2C_PCF_STS 0x2041#define I2C_PCF_BER 0x1042#define I2C_PCF_AD0 0x0843#define I2C_PCF_LRB 0x0844#define I2C_PCF_AAS 0x0445#define I2C_PCF_LAB 0x0246#define I2C_PCF_BB 0x0147 48/* The BBC devices have two I2C controllers. The first I2C controller49 * connects mainly to configuration proms (NVRAM, cpu configuration,50 * dimm types, etc.). Whereas the second I2C controller connects to51 * environmental control devices such as fans and temperature sensors.52 * The second controller also connects to the smartcard reader, if present.53 */54 55static void set_device_claimage(struct bbc_i2c_bus *bp, struct platform_device *op, int val)56{57 int i;58 59 for (i = 0; i < NUM_CHILDREN; i++) {60 if (bp->devs[i].device == op) {61 bp->devs[i].client_claimed = val;62 return;63 }64 }65}66 67#define claim_device(BP,ECHILD) set_device_claimage(BP,ECHILD,1)68#define release_device(BP,ECHILD) set_device_claimage(BP,ECHILD,0)69 70struct platform_device *bbc_i2c_getdev(struct bbc_i2c_bus *bp, int index)71{72 struct platform_device *op = NULL;73 int curidx = 0, i;74 75 for (i = 0; i < NUM_CHILDREN; i++) {76 if (!(op = bp->devs[i].device))77 break;78 if (curidx == index)79 goto out;80 op = NULL;81 curidx++;82 }83 84out:85 if (curidx == index)86 return op;87 return NULL;88}89 90struct bbc_i2c_client *bbc_i2c_attach(struct bbc_i2c_bus *bp, struct platform_device *op)91{92 struct bbc_i2c_client *client;93 const u32 *reg;94 95 client = kzalloc(sizeof(*client), GFP_KERNEL);96 if (!client)97 return NULL;98 client->bp = bp;99 client->op = op;100 101 reg = of_get_property(op->dev.of_node, "reg", NULL);102 if (!reg) {103 kfree(client);104 return NULL;105 }106 107 client->bus = reg[0];108 client->address = reg[1];109 110 claim_device(bp, op);111 112 return client;113}114 115void bbc_i2c_detach(struct bbc_i2c_client *client)116{117 struct bbc_i2c_bus *bp = client->bp;118 struct platform_device *op = client->op;119 120 release_device(bp, op);121 kfree(client);122}123 124static int wait_for_pin(struct bbc_i2c_bus *bp, u8 *status)125{126 DECLARE_WAITQUEUE(wait, current);127 int limit = 32;128 int ret = 1;129 130 bp->waiting = 1;131 add_wait_queue(&bp->wq, &wait);132 while (limit-- > 0) {133 long val;134 135 val = wait_event_interruptible_timeout(136 bp->wq,137 (((*status = readb(bp->i2c_control_regs + 0))138 & I2C_PCF_PIN) == 0),139 msecs_to_jiffies(250));140 if (val > 0) {141 ret = 0;142 break;143 }144 }145 remove_wait_queue(&bp->wq, &wait);146 bp->waiting = 0;147 148 return ret;149}150 151int bbc_i2c_writeb(struct bbc_i2c_client *client, unsigned char val, int off)152{153 struct bbc_i2c_bus *bp = client->bp;154 int address = client->address;155 u8 status;156 int ret = -1;157 158 if (bp->i2c_bussel_reg != NULL)159 writeb(client->bus, bp->i2c_bussel_reg);160 161 writeb(address, bp->i2c_control_regs + 0x1);162 writeb(I2C_PCF_START, bp->i2c_control_regs + 0x0);163 if (wait_for_pin(bp, &status))164 goto out;165 166 writeb(off, bp->i2c_control_regs + 0x1);167 if (wait_for_pin(bp, &status) ||168 (status & I2C_PCF_LRB) != 0)169 goto out;170 171 writeb(val, bp->i2c_control_regs + 0x1);172 if (wait_for_pin(bp, &status))173 goto out;174 175 ret = 0;176 177out:178 writeb(I2C_PCF_STOP, bp->i2c_control_regs + 0x0);179 return ret;180}181 182int bbc_i2c_readb(struct bbc_i2c_client *client, unsigned char *byte, int off)183{184 struct bbc_i2c_bus *bp = client->bp;185 unsigned char address = client->address, status;186 int ret = -1;187 188 if (bp->i2c_bussel_reg != NULL)189 writeb(client->bus, bp->i2c_bussel_reg);190 191 writeb(address, bp->i2c_control_regs + 0x1);192 writeb(I2C_PCF_START, bp->i2c_control_regs + 0x0);193 if (wait_for_pin(bp, &status))194 goto out;195 196 writeb(off, bp->i2c_control_regs + 0x1);197 if (wait_for_pin(bp, &status) ||198 (status & I2C_PCF_LRB) != 0)199 goto out;200 201 writeb(I2C_PCF_STOP, bp->i2c_control_regs + 0x0);202 203 address |= 0x1; /* READ */204 205 writeb(address, bp->i2c_control_regs + 0x1);206 writeb(I2C_PCF_START, bp->i2c_control_regs + 0x0);207 if (wait_for_pin(bp, &status))208 goto out;209 210 /* Set PIN back to one so the device sends the first211 * byte.212 */213 (void) readb(bp->i2c_control_regs + 0x1);214 if (wait_for_pin(bp, &status))215 goto out;216 217 writeb(I2C_PCF_ESO | I2C_PCF_ENI, bp->i2c_control_regs + 0x0);218 *byte = readb(bp->i2c_control_regs + 0x1);219 if (wait_for_pin(bp, &status))220 goto out;221 222 ret = 0;223 224out:225 writeb(I2C_PCF_STOP, bp->i2c_control_regs + 0x0);226 (void) readb(bp->i2c_control_regs + 0x1);227 228 return ret;229}230 231int bbc_i2c_write_buf(struct bbc_i2c_client *client,232 char *buf, int len, int off)233{234 int ret = 0;235 236 while (len > 0) {237 ret = bbc_i2c_writeb(client, *buf, off);238 if (ret < 0)239 break;240 len--;241 buf++;242 off++;243 }244 return ret;245}246 247int bbc_i2c_read_buf(struct bbc_i2c_client *client,248 char *buf, int len, int off)249{250 int ret = 0;251 252 while (len > 0) {253 ret = bbc_i2c_readb(client, buf, off);254 if (ret < 0)255 break;256 len--;257 buf++;258 off++;259 }260 261 return ret;262}263 264EXPORT_SYMBOL(bbc_i2c_getdev);265EXPORT_SYMBOL(bbc_i2c_attach);266EXPORT_SYMBOL(bbc_i2c_detach);267EXPORT_SYMBOL(bbc_i2c_writeb);268EXPORT_SYMBOL(bbc_i2c_readb);269EXPORT_SYMBOL(bbc_i2c_write_buf);270EXPORT_SYMBOL(bbc_i2c_read_buf);271 272static irqreturn_t bbc_i2c_interrupt(int irq, void *dev_id)273{274 struct bbc_i2c_bus *bp = dev_id;275 276 /* PIN going from set to clear is the only event which277 * makes the i2c assert an interrupt.278 */279 if (bp->waiting &&280 !(readb(bp->i2c_control_regs + 0x0) & I2C_PCF_PIN))281 wake_up_interruptible(&bp->wq);282 283 return IRQ_HANDLED;284}285 286static void reset_one_i2c(struct bbc_i2c_bus *bp)287{288 writeb(I2C_PCF_PIN, bp->i2c_control_regs + 0x0);289 writeb(bp->own, bp->i2c_control_regs + 0x1);290 writeb(I2C_PCF_PIN | I2C_PCF_ES1, bp->i2c_control_regs + 0x0);291 writeb(bp->clock, bp->i2c_control_regs + 0x1);292 writeb(I2C_PCF_IDLE, bp->i2c_control_regs + 0x0);293}294 295static struct bbc_i2c_bus * attach_one_i2c(struct platform_device *op, int index)296{297 struct bbc_i2c_bus *bp;298 struct device_node *dp;299 int entry;300 301 bp = kzalloc(sizeof(*bp), GFP_KERNEL);302 if (!bp)303 return NULL;304 305 INIT_LIST_HEAD(&bp->temps);306 INIT_LIST_HEAD(&bp->fans);307 308 bp->i2c_control_regs = of_ioremap(&op->resource[0], 0, 0x2, "bbc_i2c_regs");309 if (!bp->i2c_control_regs)310 goto fail;311 312 if (op->num_resources == 2) {313 bp->i2c_bussel_reg = of_ioremap(&op->resource[1], 0, 0x1, "bbc_i2c_bussel");314 if (!bp->i2c_bussel_reg)315 goto fail;316 }317 318 bp->waiting = 0;319 init_waitqueue_head(&bp->wq);320 if (request_irq(op->archdata.irqs[0], bbc_i2c_interrupt,321 IRQF_SHARED, "bbc_i2c", bp))322 goto fail;323 324 bp->index = index;325 bp->op = op;326 327 spin_lock_init(&bp->lock);328 329 entry = 0;330 for (dp = op->dev.of_node->child;331 dp && entry < 8;332 dp = dp->sibling, entry++) {333 struct platform_device *child_op;334 335 child_op = of_find_device_by_node(dp);336 bp->devs[entry].device = child_op;337 bp->devs[entry].client_claimed = 0;338 }339 340 writeb(I2C_PCF_PIN, bp->i2c_control_regs + 0x0);341 bp->own = readb(bp->i2c_control_regs + 0x01);342 writeb(I2C_PCF_PIN | I2C_PCF_ES1, bp->i2c_control_regs + 0x0);343 bp->clock = readb(bp->i2c_control_regs + 0x01);344 345 printk(KERN_INFO "i2c-%d: Regs at %p, %d devices, own %02x, clock %02x.\n",346 bp->index, bp->i2c_control_regs, entry, bp->own, bp->clock);347 348 reset_one_i2c(bp);349 350 return bp;351 352fail:353 if (bp->i2c_bussel_reg)354 of_iounmap(&op->resource[1], bp->i2c_bussel_reg, 1);355 if (bp->i2c_control_regs)356 of_iounmap(&op->resource[0], bp->i2c_control_regs, 2);357 kfree(bp);358 return NULL;359}360 361static int bbc_i2c_probe(struct platform_device *op)362{363 struct bbc_i2c_bus *bp;364 int err, index = 0;365 366 bp = attach_one_i2c(op, index);367 if (!bp)368 return -EINVAL;369 370 err = bbc_envctrl_init(bp);371 if (err) {372 free_irq(op->archdata.irqs[0], bp);373 if (bp->i2c_bussel_reg)374 of_iounmap(&op->resource[0], bp->i2c_bussel_reg, 1);375 if (bp->i2c_control_regs)376 of_iounmap(&op->resource[1], bp->i2c_control_regs, 2);377 kfree(bp);378 } else {379 dev_set_drvdata(&op->dev, bp);380 }381 382 return err;383}384 385static void bbc_i2c_remove(struct platform_device *op)386{387 struct bbc_i2c_bus *bp = dev_get_drvdata(&op->dev);388 389 bbc_envctrl_cleanup(bp);390 391 free_irq(op->archdata.irqs[0], bp);392 393 if (bp->i2c_bussel_reg)394 of_iounmap(&op->resource[0], bp->i2c_bussel_reg, 1);395 if (bp->i2c_control_regs)396 of_iounmap(&op->resource[1], bp->i2c_control_regs, 2);397 398 kfree(bp);399}400 401static const struct of_device_id bbc_i2c_match[] = {402 {403 .name = "i2c",404 .compatible = "SUNW,bbc-i2c",405 },406 {},407};408MODULE_DEVICE_TABLE(of, bbc_i2c_match);409 410static struct platform_driver bbc_i2c_driver = {411 .driver = {412 .name = "bbc_i2c",413 .of_match_table = bbc_i2c_match,414 },415 .probe = bbc_i2c_probe,416 .remove_new = bbc_i2c_remove,417};418 419module_platform_driver(bbc_i2c_driver);420 421MODULE_DESCRIPTION("UltraSPARC-III bootbus i2c controller driver");422MODULE_LICENSE("GPL");423