Orange Pi5 kernel

Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards

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orangepi/linux-orangepi-5.10.y.git/trunk/drivers/sbus/char/bbc_i2c.c
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// SPDX-License-Identifier: GPL-2.0-only
/* bbc_i2c.c: I2C low-level driver for BBC device on UltraSPARC-III
 *            platforms.
 *
 * Copyright (C) 2001, 2008 David S. Miller (davem@davemloft.net)
 */
 
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <asm/bbc.h>
#include <asm/io.h>
 
#include "bbc_i2c.h"
 
/* Convert this driver to use i2c bus layer someday... */
#define I2C_PCF_PIN	0x80
#define I2C_PCF_ESO	0x40
#define I2C_PCF_ES1	0x20
#define I2C_PCF_ES2	0x10
#define I2C_PCF_ENI	0x08
#define I2C_PCF_STA	0x04
#define I2C_PCF_STO	0x02
#define I2C_PCF_ACK	0x01
 
#define I2C_PCF_START    (I2C_PCF_PIN | I2C_PCF_ESO | I2C_PCF_ENI | I2C_PCF_STA | I2C_PCF_ACK)
#define I2C_PCF_STOP     (I2C_PCF_PIN | I2C_PCF_ESO | I2C_PCF_STO | I2C_PCF_ACK)
#define I2C_PCF_REPSTART (              I2C_PCF_ESO | I2C_PCF_STA | I2C_PCF_ACK)
#define I2C_PCF_IDLE     (I2C_PCF_PIN | I2C_PCF_ESO               | I2C_PCF_ACK)
 
#define I2C_PCF_INI 0x40   /* 1 if not initialized */
#define I2C_PCF_STS 0x20
#define I2C_PCF_BER 0x10
#define I2C_PCF_AD0 0x08
#define I2C_PCF_LRB 0x08
#define I2C_PCF_AAS 0x04
#define I2C_PCF_LAB 0x02
#define I2C_PCF_BB  0x01
 
/* The BBC devices have two I2C controllers.  The first I2C controller
 * connects mainly to configuration proms (NVRAM, cpu configuration,
 * dimm types, etc.).  Whereas the second I2C controller connects to
 * environmental control devices such as fans and temperature sensors.
 * The second controller also connects to the smartcard reader, if present.
 */
 
static void set_device_claimage(struct bbc_i2c_bus *bp, struct platform_device *op, int val)
{
<------>int i;
 
<------>for (i = 0; i < NUM_CHILDREN; i++) {
<------><------>if (bp->devs[i].device == op) {
<------><------><------>bp->devs[i].client_claimed = val;
<------><------><------>return;
<------><------>}
<------>}
}
 
#define claim_device(BP,ECHILD)		set_device_claimage(BP,ECHILD,1)
#define release_device(BP,ECHILD)	set_device_claimage(BP,ECHILD,0)
 
struct platform_device *bbc_i2c_getdev(struct bbc_i2c_bus *bp, int index)
{
<------>struct platform_device *op = NULL;
<------>int curidx = 0, i;
 
<------>for (i = 0; i < NUM_CHILDREN; i++) {
<------><------>if (!(op = bp->devs[i].device))
<------><------><------>break;
<------><------>if (curidx == index)
<------><------><------>goto out;
<------><------>op = NULL;
<------><------>curidx++;
<------>}
 
out:
<------>if (curidx == index)
<------><------>return op;
<------>return NULL;
}
 
struct bbc_i2c_client *bbc_i2c_attach(struct bbc_i2c_bus *bp, struct platform_device *op)
{
<------>struct bbc_i2c_client *client;
<------>const u32 *reg;
 
<------>client = kzalloc(sizeof(*client), GFP_KERNEL);
<------>if (!client)
<------><------>return NULL;
<------>client->bp = bp;
<------>client->op = op;
 
<------>reg = of_get_property(op->dev.of_node, "reg", NULL);
<------>if (!reg) {
<------><------>kfree(client);
<------><------>return NULL;
<------>}
 
<------>client->bus = reg[0];
<------>client->address = reg[1];
 
<------>claim_device(bp, op);
 
<------>return client;
}
 
void bbc_i2c_detach(struct bbc_i2c_client *client)
{
<------>struct bbc_i2c_bus *bp = client->bp;
<------>struct platform_device *op = client->op;
 
<------>release_device(bp, op);
<------>kfree(client);
}
 
static int wait_for_pin(struct bbc_i2c_bus *bp, u8 *status)
{
<------>DECLARE_WAITQUEUE(wait, current);
<------>int limit = 32;
<------>int ret = 1;
 
<------>bp->waiting = 1;
<------>add_wait_queue(&bp->wq, &wait);
<------>while (limit-- > 0) {
<------><------>long val;
 
<------><------>val = wait_event_interruptible_timeout(
<------><------><------><------>bp->wq,
<------><------><------><------>(((*status = readb(bp->i2c_control_regs + 0))
<------><------><------><------>  & I2C_PCF_PIN) == 0),
<------><------><------><------>msecs_to_jiffies(250));
<------><------>if (val > 0) {
<------><------><------>ret = 0;
<------><------><------>break;
<------><------>}
<------>}
<------>remove_wait_queue(&bp->wq, &wait);
<------>bp->waiting = 0;
 
<------>return ret;
}
 
int bbc_i2c_writeb(struct bbc_i2c_client *client, unsigned char val, int off)
{
<------>struct bbc_i2c_bus *bp = client->bp;
<------>int address = client->address;
<------>u8 status;
<------>int ret = -1;
 
<------>if (bp->i2c_bussel_reg != NULL)
<------><------>writeb(client->bus, bp->i2c_bussel_reg);
 
<------>writeb(address, bp->i2c_control_regs + 0x1);
<------>writeb(I2C_PCF_START, bp->i2c_control_regs + 0x0);
<------>if (wait_for_pin(bp, &status))
<------><------>goto out;
 
<------>writeb(off, bp->i2c_control_regs + 0x1);
<------>if (wait_for_pin(bp, &status) ||
<------>    (status & I2C_PCF_LRB) != 0)
<------><------>goto out;
 
<------>writeb(val, bp->i2c_control_regs + 0x1);
<------>if (wait_for_pin(bp, &status))
<------><------>goto out;
 
<------>ret = 0;
 
out:
<------>writeb(I2C_PCF_STOP, bp->i2c_control_regs + 0x0);
<------>return ret;
}
 
int bbc_i2c_readb(struct bbc_i2c_client *client, unsigned char *byte, int off)
{
<------>struct bbc_i2c_bus *bp = client->bp;
<------>unsigned char address = client->address, status;
<------>int ret = -1;
 
<------>if (bp->i2c_bussel_reg != NULL)
<------><------>writeb(client->bus, bp->i2c_bussel_reg);
 
<------>writeb(address, bp->i2c_control_regs + 0x1);
<------>writeb(I2C_PCF_START, bp->i2c_control_regs + 0x0);
<------>if (wait_for_pin(bp, &status))
<------><------>goto out;
 
<------>writeb(off, bp->i2c_control_regs + 0x1);
<------>if (wait_for_pin(bp, &status) ||
<------>    (status & I2C_PCF_LRB) != 0)
<------><------>goto out;
 
<------>writeb(I2C_PCF_STOP, bp->i2c_control_regs + 0x0);
 
<------>address |= 0x1; /* READ */
 
<------>writeb(address, bp->i2c_control_regs + 0x1);
<------>writeb(I2C_PCF_START, bp->i2c_control_regs + 0x0);
<------>if (wait_for_pin(bp, &status))
<------><------>goto out;
 
<------>/* Set PIN back to one so the device sends the first
<------> * byte.
<------> */
<------>(void) readb(bp->i2c_control_regs + 0x1);
<------>if (wait_for_pin(bp, &status))
<------><------>goto out;
 
<------>writeb(I2C_PCF_ESO | I2C_PCF_ENI, bp->i2c_control_regs + 0x0);
<------>*byte = readb(bp->i2c_control_regs + 0x1);
<------>if (wait_for_pin(bp, &status))
<------><------>goto out;
 
<------>ret = 0;
 
out:
<------>writeb(I2C_PCF_STOP, bp->i2c_control_regs + 0x0);
<------>(void) readb(bp->i2c_control_regs + 0x1);
 
<------>return ret;
}
 
int bbc_i2c_write_buf(struct bbc_i2c_client *client,
<------><------>      char *buf, int len, int off)
{
<------>int ret = 0;
 
<------>while (len > 0) {
<------><------>ret = bbc_i2c_writeb(client, *buf, off);
<------><------>if (ret < 0)
<------><------><------>break;
<------><------>len--;
<------><------>buf++;
<------><------>off++;
<------>}
<------>return ret;
}
 
int bbc_i2c_read_buf(struct bbc_i2c_client *client,
<------><------>     char *buf, int len, int off)
{
<------>int ret = 0;
 
<------>while (len > 0) {
<------><------>ret = bbc_i2c_readb(client, buf, off);
<------><------>if (ret < 0)
<------><------><------>break;
<------><------>len--;
<------><------>buf++;
<------><------>off++;
<------>}
 
<------>return ret;
}
 
EXPORT_SYMBOL(bbc_i2c_getdev);
EXPORT_SYMBOL(bbc_i2c_attach);
EXPORT_SYMBOL(bbc_i2c_detach);
EXPORT_SYMBOL(bbc_i2c_writeb);
EXPORT_SYMBOL(bbc_i2c_readb);
EXPORT_SYMBOL(bbc_i2c_write_buf);
EXPORT_SYMBOL(bbc_i2c_read_buf);
 
static irqreturn_t bbc_i2c_interrupt(int irq, void *dev_id)
{
<------>struct bbc_i2c_bus *bp = dev_id;
 
<------>/* PIN going from set to clear is the only event which
<------> * makes the i2c assert an interrupt.
<------> */
<------>if (bp->waiting &&
<------>    !(readb(bp->i2c_control_regs + 0x0) & I2C_PCF_PIN))
<------><------>wake_up_interruptible(&bp->wq);
 
<------>return IRQ_HANDLED;
}
 
static void reset_one_i2c(struct bbc_i2c_bus *bp)
{
<------>writeb(I2C_PCF_PIN, bp->i2c_control_regs + 0x0);
<------>writeb(bp->own, bp->i2c_control_regs + 0x1);
<------>writeb(I2C_PCF_PIN | I2C_PCF_ES1, bp->i2c_control_regs + 0x0);
<------>writeb(bp->clock, bp->i2c_control_regs + 0x1);
<------>writeb(I2C_PCF_IDLE, bp->i2c_control_regs + 0x0);
}
 
static struct bbc_i2c_bus * attach_one_i2c(struct platform_device *op, int index)
{
<------>struct bbc_i2c_bus *bp;
<------>struct device_node *dp;
<------>int entry;
 
<------>bp = kzalloc(sizeof(*bp), GFP_KERNEL);
<------>if (!bp)
<------><------>return NULL;
 
<------>INIT_LIST_HEAD(&bp->temps);
<------>INIT_LIST_HEAD(&bp->fans);
 
<------>bp->i2c_control_regs = of_ioremap(&op->resource[0], 0, 0x2, "bbc_i2c_regs");
<------>if (!bp->i2c_control_regs)
<------><------>goto fail;
 
<------>if (op->num_resources == 2) {
<------><------>bp->i2c_bussel_reg = of_ioremap(&op->resource[1], 0, 0x1, "bbc_i2c_bussel");
<------><------>if (!bp->i2c_bussel_reg)
<------><------><------>goto fail;
<------>}
 
<------>bp->waiting = 0;
<------>init_waitqueue_head(&bp->wq);
<------>if (request_irq(op->archdata.irqs[0], bbc_i2c_interrupt,
<------><------><------>IRQF_SHARED, "bbc_i2c", bp))
<------><------>goto fail;
 
<------>bp->index = index;
<------>bp->op = op;
 
<------>spin_lock_init(&bp->lock);
 
<------>entry = 0;
<------>for (dp = op->dev.of_node->child;
<------>     dp && entry < 8;
<------>     dp = dp->sibling, entry++) {
<------><------>struct platform_device *child_op;
 
<------><------>child_op = of_find_device_by_node(dp);
<------><------>bp->devs[entry].device = child_op;
<------><------>bp->devs[entry].client_claimed = 0;
<------>}
 
<------>writeb(I2C_PCF_PIN, bp->i2c_control_regs + 0x0);
<------>bp->own = readb(bp->i2c_control_regs + 0x01);
<------>writeb(I2C_PCF_PIN | I2C_PCF_ES1, bp->i2c_control_regs + 0x0);
<------>bp->clock = readb(bp->i2c_control_regs + 0x01);
 
<------>printk(KERN_INFO "i2c-%d: Regs at %p, %d devices, own %02x, clock %02x.\n",
<------>       bp->index, bp->i2c_control_regs, entry, bp->own, bp->clock);
 
<------>reset_one_i2c(bp);
 
<------>return bp;
 
fail:
<------>if (bp->i2c_bussel_reg)
<------><------>of_iounmap(&op->resource[1], bp->i2c_bussel_reg, 1);
<------>if (bp->i2c_control_regs)
<------><------>of_iounmap(&op->resource[0], bp->i2c_control_regs, 2);
<------>kfree(bp);
<------>return NULL;
}
 
extern int bbc_envctrl_init(struct bbc_i2c_bus *bp);
extern void bbc_envctrl_cleanup(struct bbc_i2c_bus *bp);
 
static int bbc_i2c_probe(struct platform_device *op)
{
<------>struct bbc_i2c_bus *bp;
<------>int err, index = 0;
 
<------>bp = attach_one_i2c(op, index);
<------>if (!bp)
<------><------>return -EINVAL;
 
<------>err = bbc_envctrl_init(bp);
<------>if (err) {
<------><------>free_irq(op->archdata.irqs[0], bp);
<------><------>if (bp->i2c_bussel_reg)
<------><------><------>of_iounmap(&op->resource[0], bp->i2c_bussel_reg, 1);
<------><------>if (bp->i2c_control_regs)
<------><------><------>of_iounmap(&op->resource[1], bp->i2c_control_regs, 2);
<------><------>kfree(bp);
<------>} else {
<------><------>dev_set_drvdata(&op->dev, bp);
<------>}
 
<------>return err;
}
 
static int bbc_i2c_remove(struct platform_device *op)
{
<------>struct bbc_i2c_bus *bp = dev_get_drvdata(&op->dev);
 
<------>bbc_envctrl_cleanup(bp);
 
<------>free_irq(op->archdata.irqs[0], bp);
 
<------>if (bp->i2c_bussel_reg)
<------><------>of_iounmap(&op->resource[0], bp->i2c_bussel_reg, 1);
<------>if (bp->i2c_control_regs)
<------><------>of_iounmap(&op->resource[1], bp->i2c_control_regs, 2);
 
<------>kfree(bp);
 
<------>return 0;
}
 
static const struct of_device_id bbc_i2c_match[] = {
<------>{
<------><------>.name = "i2c",
<------><------>.compatible = "SUNW,bbc-i2c",
<------>},
<------>{},
};
MODULE_DEVICE_TABLE(of, bbc_i2c_match);
 
static struct platform_driver bbc_i2c_driver = {
<------>.driver = {
<------><------>.name = "bbc_i2c",
<------><------>.of_match_table = bbc_i2c_match,
<------>},
<------>.probe		= bbc_i2c_probe,
<------>.remove		= bbc_i2c_remove,
};
 
module_platform_driver(bbc_i2c_driver);
 
MODULE_LICENSE("GPL");
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