426 lines
9.5 KiB
C
426 lines
9.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/* bbc_i2c.c: I2C low-level driver for BBC device on UltraSPARC-III
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* platforms.
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*
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* Copyright (C) 2001, 2008 David S. Miller (davem@davemloft.net)
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/types.h>
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#include <linux/slab.h>
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#include <linux/sched.h>
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#include <linux/wait.h>
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#include <linux/delay.h>
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#include <linux/interrupt.h>
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#include <linux/of.h>
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#include <linux/of_device.h>
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#include <asm/bbc.h>
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#include <asm/io.h>
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#include "bbc_i2c.h"
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/* Convert this driver to use i2c bus layer someday... */
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#define I2C_PCF_PIN 0x80
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#define I2C_PCF_ESO 0x40
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#define I2C_PCF_ES1 0x20
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#define I2C_PCF_ES2 0x10
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#define I2C_PCF_ENI 0x08
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#define I2C_PCF_STA 0x04
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#define I2C_PCF_STO 0x02
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#define I2C_PCF_ACK 0x01
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#define I2C_PCF_START (I2C_PCF_PIN | I2C_PCF_ESO | I2C_PCF_ENI | I2C_PCF_STA | I2C_PCF_ACK)
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#define I2C_PCF_STOP (I2C_PCF_PIN | I2C_PCF_ESO | I2C_PCF_STO | I2C_PCF_ACK)
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#define I2C_PCF_REPSTART ( I2C_PCF_ESO | I2C_PCF_STA | I2C_PCF_ACK)
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#define I2C_PCF_IDLE (I2C_PCF_PIN | I2C_PCF_ESO | I2C_PCF_ACK)
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#define I2C_PCF_INI 0x40 /* 1 if not initialized */
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#define I2C_PCF_STS 0x20
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#define I2C_PCF_BER 0x10
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#define I2C_PCF_AD0 0x08
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#define I2C_PCF_LRB 0x08
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#define I2C_PCF_AAS 0x04
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#define I2C_PCF_LAB 0x02
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#define I2C_PCF_BB 0x01
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/* The BBC devices have two I2C controllers. The first I2C controller
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* connects mainly to configuration proms (NVRAM, cpu configuration,
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* dimm types, etc.). Whereas the second I2C controller connects to
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* environmental control devices such as fans and temperature sensors.
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* The second controller also connects to the smartcard reader, if present.
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*/
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static void set_device_claimage(struct bbc_i2c_bus *bp, struct platform_device *op, int val)
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{
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int i;
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for (i = 0; i < NUM_CHILDREN; i++) {
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if (bp->devs[i].device == op) {
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bp->devs[i].client_claimed = val;
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return;
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}
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}
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}
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#define claim_device(BP,ECHILD) set_device_claimage(BP,ECHILD,1)
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#define release_device(BP,ECHILD) set_device_claimage(BP,ECHILD,0)
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struct platform_device *bbc_i2c_getdev(struct bbc_i2c_bus *bp, int index)
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{
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struct platform_device *op = NULL;
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int curidx = 0, i;
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for (i = 0; i < NUM_CHILDREN; i++) {
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if (!(op = bp->devs[i].device))
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break;
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if (curidx == index)
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goto out;
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op = NULL;
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curidx++;
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}
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out:
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if (curidx == index)
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return op;
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return NULL;
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}
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struct bbc_i2c_client *bbc_i2c_attach(struct bbc_i2c_bus *bp, struct platform_device *op)
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{
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struct bbc_i2c_client *client;
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const u32 *reg;
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client = kzalloc(sizeof(*client), GFP_KERNEL);
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if (!client)
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return NULL;
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client->bp = bp;
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client->op = op;
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reg = of_get_property(op->dev.of_node, "reg", NULL);
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if (!reg) {
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kfree(client);
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return NULL;
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}
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client->bus = reg[0];
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client->address = reg[1];
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claim_device(bp, op);
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return client;
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}
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void bbc_i2c_detach(struct bbc_i2c_client *client)
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{
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struct bbc_i2c_bus *bp = client->bp;
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struct platform_device *op = client->op;
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release_device(bp, op);
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kfree(client);
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}
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static int wait_for_pin(struct bbc_i2c_bus *bp, u8 *status)
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{
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DECLARE_WAITQUEUE(wait, current);
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int limit = 32;
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int ret = 1;
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bp->waiting = 1;
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add_wait_queue(&bp->wq, &wait);
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while (limit-- > 0) {
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long val;
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val = wait_event_interruptible_timeout(
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bp->wq,
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(((*status = readb(bp->i2c_control_regs + 0))
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& I2C_PCF_PIN) == 0),
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msecs_to_jiffies(250));
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if (val > 0) {
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ret = 0;
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break;
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}
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}
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remove_wait_queue(&bp->wq, &wait);
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bp->waiting = 0;
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return ret;
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}
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int bbc_i2c_writeb(struct bbc_i2c_client *client, unsigned char val, int off)
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{
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struct bbc_i2c_bus *bp = client->bp;
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int address = client->address;
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u8 status;
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int ret = -1;
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if (bp->i2c_bussel_reg != NULL)
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writeb(client->bus, bp->i2c_bussel_reg);
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writeb(address, bp->i2c_control_regs + 0x1);
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writeb(I2C_PCF_START, bp->i2c_control_regs + 0x0);
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if (wait_for_pin(bp, &status))
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goto out;
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writeb(off, bp->i2c_control_regs + 0x1);
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if (wait_for_pin(bp, &status) ||
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(status & I2C_PCF_LRB) != 0)
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goto out;
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writeb(val, bp->i2c_control_regs + 0x1);
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if (wait_for_pin(bp, &status))
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goto out;
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ret = 0;
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out:
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writeb(I2C_PCF_STOP, bp->i2c_control_regs + 0x0);
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return ret;
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}
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int bbc_i2c_readb(struct bbc_i2c_client *client, unsigned char *byte, int off)
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{
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struct bbc_i2c_bus *bp = client->bp;
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unsigned char address = client->address, status;
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int ret = -1;
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if (bp->i2c_bussel_reg != NULL)
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writeb(client->bus, bp->i2c_bussel_reg);
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writeb(address, bp->i2c_control_regs + 0x1);
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writeb(I2C_PCF_START, bp->i2c_control_regs + 0x0);
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if (wait_for_pin(bp, &status))
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goto out;
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writeb(off, bp->i2c_control_regs + 0x1);
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if (wait_for_pin(bp, &status) ||
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(status & I2C_PCF_LRB) != 0)
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goto out;
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writeb(I2C_PCF_STOP, bp->i2c_control_regs + 0x0);
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address |= 0x1; /* READ */
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writeb(address, bp->i2c_control_regs + 0x1);
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writeb(I2C_PCF_START, bp->i2c_control_regs + 0x0);
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if (wait_for_pin(bp, &status))
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goto out;
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/* Set PIN back to one so the device sends the first
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* byte.
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*/
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(void) readb(bp->i2c_control_regs + 0x1);
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if (wait_for_pin(bp, &status))
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goto out;
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writeb(I2C_PCF_ESO | I2C_PCF_ENI, bp->i2c_control_regs + 0x0);
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*byte = readb(bp->i2c_control_regs + 0x1);
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if (wait_for_pin(bp, &status))
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goto out;
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ret = 0;
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out:
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writeb(I2C_PCF_STOP, bp->i2c_control_regs + 0x0);
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(void) readb(bp->i2c_control_regs + 0x1);
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return ret;
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}
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int bbc_i2c_write_buf(struct bbc_i2c_client *client,
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char *buf, int len, int off)
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{
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int ret = 0;
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while (len > 0) {
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ret = bbc_i2c_writeb(client, *buf, off);
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if (ret < 0)
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break;
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len--;
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buf++;
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off++;
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}
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return ret;
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}
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int bbc_i2c_read_buf(struct bbc_i2c_client *client,
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char *buf, int len, int off)
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{
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int ret = 0;
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while (len > 0) {
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ret = bbc_i2c_readb(client, buf, off);
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if (ret < 0)
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break;
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len--;
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buf++;
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off++;
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}
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return ret;
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}
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EXPORT_SYMBOL(bbc_i2c_getdev);
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EXPORT_SYMBOL(bbc_i2c_attach);
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EXPORT_SYMBOL(bbc_i2c_detach);
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EXPORT_SYMBOL(bbc_i2c_writeb);
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EXPORT_SYMBOL(bbc_i2c_readb);
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EXPORT_SYMBOL(bbc_i2c_write_buf);
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EXPORT_SYMBOL(bbc_i2c_read_buf);
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static irqreturn_t bbc_i2c_interrupt(int irq, void *dev_id)
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{
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struct bbc_i2c_bus *bp = dev_id;
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/* PIN going from set to clear is the only event which
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* makes the i2c assert an interrupt.
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*/
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if (bp->waiting &&
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!(readb(bp->i2c_control_regs + 0x0) & I2C_PCF_PIN))
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wake_up_interruptible(&bp->wq);
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return IRQ_HANDLED;
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}
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static void reset_one_i2c(struct bbc_i2c_bus *bp)
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{
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writeb(I2C_PCF_PIN, bp->i2c_control_regs + 0x0);
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writeb(bp->own, bp->i2c_control_regs + 0x1);
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writeb(I2C_PCF_PIN | I2C_PCF_ES1, bp->i2c_control_regs + 0x0);
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writeb(bp->clock, bp->i2c_control_regs + 0x1);
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writeb(I2C_PCF_IDLE, bp->i2c_control_regs + 0x0);
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}
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static struct bbc_i2c_bus * attach_one_i2c(struct platform_device *op, int index)
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{
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struct bbc_i2c_bus *bp;
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struct device_node *dp;
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int entry;
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bp = kzalloc(sizeof(*bp), GFP_KERNEL);
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if (!bp)
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return NULL;
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INIT_LIST_HEAD(&bp->temps);
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INIT_LIST_HEAD(&bp->fans);
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bp->i2c_control_regs = of_ioremap(&op->resource[0], 0, 0x2, "bbc_i2c_regs");
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if (!bp->i2c_control_regs)
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goto fail;
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if (op->num_resources == 2) {
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bp->i2c_bussel_reg = of_ioremap(&op->resource[1], 0, 0x1, "bbc_i2c_bussel");
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if (!bp->i2c_bussel_reg)
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goto fail;
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}
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bp->waiting = 0;
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init_waitqueue_head(&bp->wq);
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if (request_irq(op->archdata.irqs[0], bbc_i2c_interrupt,
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IRQF_SHARED, "bbc_i2c", bp))
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goto fail;
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bp->index = index;
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bp->op = op;
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spin_lock_init(&bp->lock);
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entry = 0;
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for (dp = op->dev.of_node->child;
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dp && entry < 8;
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dp = dp->sibling, entry++) {
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struct platform_device *child_op;
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child_op = of_find_device_by_node(dp);
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bp->devs[entry].device = child_op;
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bp->devs[entry].client_claimed = 0;
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}
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writeb(I2C_PCF_PIN, bp->i2c_control_regs + 0x0);
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bp->own = readb(bp->i2c_control_regs + 0x01);
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writeb(I2C_PCF_PIN | I2C_PCF_ES1, bp->i2c_control_regs + 0x0);
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bp->clock = readb(bp->i2c_control_regs + 0x01);
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printk(KERN_INFO "i2c-%d: Regs at %p, %d devices, own %02x, clock %02x.\n",
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bp->index, bp->i2c_control_regs, entry, bp->own, bp->clock);
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reset_one_i2c(bp);
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return bp;
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fail:
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if (bp->i2c_bussel_reg)
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of_iounmap(&op->resource[1], bp->i2c_bussel_reg, 1);
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if (bp->i2c_control_regs)
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of_iounmap(&op->resource[0], bp->i2c_control_regs, 2);
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kfree(bp);
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return NULL;
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}
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extern int bbc_envctrl_init(struct bbc_i2c_bus *bp);
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extern void bbc_envctrl_cleanup(struct bbc_i2c_bus *bp);
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static int bbc_i2c_probe(struct platform_device *op)
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{
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struct bbc_i2c_bus *bp;
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int err, index = 0;
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bp = attach_one_i2c(op, index);
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if (!bp)
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return -EINVAL;
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err = bbc_envctrl_init(bp);
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if (err) {
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free_irq(op->archdata.irqs[0], bp);
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if (bp->i2c_bussel_reg)
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of_iounmap(&op->resource[0], bp->i2c_bussel_reg, 1);
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if (bp->i2c_control_regs)
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of_iounmap(&op->resource[1], bp->i2c_control_regs, 2);
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kfree(bp);
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} else {
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dev_set_drvdata(&op->dev, bp);
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}
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return err;
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}
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static int bbc_i2c_remove(struct platform_device *op)
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{
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struct bbc_i2c_bus *bp = dev_get_drvdata(&op->dev);
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bbc_envctrl_cleanup(bp);
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free_irq(op->archdata.irqs[0], bp);
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if (bp->i2c_bussel_reg)
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of_iounmap(&op->resource[0], bp->i2c_bussel_reg, 1);
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if (bp->i2c_control_regs)
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of_iounmap(&op->resource[1], bp->i2c_control_regs, 2);
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kfree(bp);
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return 0;
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}
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static const struct of_device_id bbc_i2c_match[] = {
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{
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.name = "i2c",
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.compatible = "SUNW,bbc-i2c",
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},
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{},
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};
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MODULE_DEVICE_TABLE(of, bbc_i2c_match);
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static struct platform_driver bbc_i2c_driver = {
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.driver = {
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.name = "bbc_i2c",
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.of_match_table = bbc_i2c_match,
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},
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.probe = bbc_i2c_probe,
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.remove = bbc_i2c_remove,
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};
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module_platform_driver(bbc_i2c_driver);
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MODULE_LICENSE("GPL");
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