+++ /dev/null
-/*
- * Cavium CNS3xxx I2C Host Controller
- *
- * Copyright 2010 Cavium Network
- * Copyright 2012 Gateworks Corporation
- * Chris Lang <clang@gateworks.com>
- * Tim Harvey <tharvey@gateworks.com>
- *
- * This file is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License, Version 2, as
- * published by the Free Software Foundation.
- */
-
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/init.h>
-#include <linux/platform_device.h>
-#include <asm/io.h>
-#include <linux/wait.h>
-#include <linux/interrupt.h>
-#include <linux/delay.h>
-#include <linux/i2c.h>
-#include <linux/slab.h>
-#include <linux/clk.h>
-
-/*
- * We need the memory map
- */
-
-#define I2C_MEM_MAP_ADDR(x) (i2c->base + x)
-#define I2C_MEM_MAP_VALUE(x) (*((unsigned int volatile*)I2C_MEM_MAP_ADDR(x)))
-
-#define I2C_CONTROLLER_REG I2C_MEM_MAP_VALUE(0x00)
-#define I2C_TIME_OUT_REG I2C_MEM_MAP_VALUE(0x04)
-#define I2C_SLAVE_ADDRESS_REG I2C_MEM_MAP_VALUE(0x08)
-#define I2C_WRITE_DATA_REG I2C_MEM_MAP_VALUE(0x0C)
-#define I2C_READ_DATA_REG I2C_MEM_MAP_VALUE(0x10)
-#define I2C_INTERRUPT_STATUS_REG I2C_MEM_MAP_VALUE(0x14)
-#define I2C_INTERRUPT_ENABLE_REG I2C_MEM_MAP_VALUE(0x18)
-#define I2C_TWI_OUT_DLY_REG I2C_MEM_MAP_VALUE(0x1C)
-
-#define I2C_BUS_ERROR_FLAG (0x1)
-#define I2C_ACTION_DONE_FLAG (0x2)
-
-#define CNS3xxx_I2C_ENABLE() (I2C_CONTROLLER_REG) |= ((unsigned int)0x1 << 31)
-#define CNS3xxx_I2C_DISABLE() (I2C_CONTROLLER_REG) &= ~((unsigned int)0x1 << 31)
-#define CNS3xxx_I2C_ENABLE_INTR() (I2C_INTERRUPT_ENABLE_REG) |= 0x03
-#define CNS3xxx_I2C_DISABLE_INTR() (I2C_INTERRUPT_ENABLE_REG) &= 0xfc
-
-#define TWI_TIMEOUT (10*HZ)
-#define I2C_100KHZ 100000
-#define I2C_200KHZ 200000
-#define I2C_300KHZ 300000
-#define I2C_400KHZ 400000
-
-#define CNS3xxx_I2C_CLK I2C_100KHZ
-
-#define STATE_DONE 1
-#define STATE_ERROR 2
-
-struct cns3xxx_i2c {
- struct device *dev;
- void __iomem *base; /* virtual */
- wait_queue_head_t wait;
- struct i2c_adapter adap;
- struct i2c_msg *msg;
- u8 state; /* see STATE_ */
- u8 error; /* see TWI_STATUS register */
- int rd_wr_len;
- u8 *buf;
-};
-
-static u32 cns3xxx_i2c_func(struct i2c_adapter *adap)
-{
- return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
-}
-
-static int
-cns3xxx_i2c_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg)
-{
- struct cns3xxx_i2c *i2c = i2c_get_adapdata(adap);
- int i, j;
- u8 buf[1] = { 0 };
-
- if (msg->len == 0) {
- /*
- * We are probably doing a probe for a device here,
- * so set the length to one, and data to 0
- */
- msg->len = 1;
- i2c->buf = buf;
- } else {
- i2c->buf = msg->buf;
- }
-
- if (msg->flags & I2C_M_TEN) {
- printk
- ("%s:%d: Presently the driver does not handle extended addressing\n",
- __FUNCTION__, __LINE__);
- return -EINVAL;
- }
- i2c->msg = msg;
-
- for (i = 0; i < msg->len; i++) {
- if (msg->len - i >= 4)
- i2c->rd_wr_len = 3;
- else
- i2c->rd_wr_len = msg->len - i - 1;
-
- // Set Data Width and TWI_EN
- I2C_CONTROLLER_REG = 0x80000000 | (i2c->rd_wr_len << 2) | (i2c->rd_wr_len);
-
- // Clear Write Reg
- I2C_WRITE_DATA_REG = 0;
-
- // Set the slave address
- I2C_SLAVE_ADDRESS_REG = (msg->addr << 1);
-
- // Are we Writing
- if (!(msg->flags & I2C_M_RD)) {
- I2C_CONTROLLER_REG |= (1 << 4);
- if (i != 0) {
- /*
- * We need to set the address in the first byte.
- * The base address is going to be in buf[0] and then
- * it needs to be incremented by i - 1.
- */
- i2c->buf--;
- *i2c->buf = buf[0] + i - 1;
-
- if (i2c->rd_wr_len < 3) {
- i += i2c->rd_wr_len;
- i2c->rd_wr_len++;
- I2C_CONTROLLER_REG = 0x80000000 | (1 << 4) | (i2c->rd_wr_len << 2) | (i2c->rd_wr_len);
- } else {
- i += i2c->rd_wr_len - 1;
- }
- } else {
- i += i2c->rd_wr_len;
- buf[0] = *i2c->buf;
- }
- for (j = 0; j <= i2c->rd_wr_len; j++) {
- I2C_WRITE_DATA_REG |= ((*i2c->buf++) << (8 * j));
- }
- } else {
- i += i2c->rd_wr_len;
- }
-
- // Start the Transfer
- i2c->state = 0; // Clear out the State
- i2c->error = 0;
- I2C_CONTROLLER_REG |= (1 << 6);
-
- if (wait_event_timeout(i2c->wait, (i2c->state == STATE_ERROR) ||
- (i2c->state == STATE_DONE), TWI_TIMEOUT)) {
- if (i2c->state == STATE_ERROR) {
- dev_dbg(i2c->dev, "controller error: 0x%2x", i2c->error);
- return -EAGAIN; // try again
- }
- } else {
- dev_err(i2c->dev, "controller timed out "
- "waiting for start condition to finish\n");
- return -ETIMEDOUT;
- }
- }
- return 0;
-}
-
-static int
-cns3xxx_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
-{
- int i;
- int ret;
- for (i = 0; i < num; i++)
- {
- ret = cns3xxx_i2c_xfer_msg(adap, &msgs[i]);
- if (ret < 0) {
- return ret;
- }
- }
- return num;
-}
-
-
-static struct i2c_algorithm cns3xxx_i2c_algo = {
- .master_xfer = cns3xxx_i2c_xfer,
- .functionality = cns3xxx_i2c_func,
-};
-
-static struct i2c_adapter cns3xxx_i2c_adapter = {
- .owner = THIS_MODULE,
- .algo = &cns3xxx_i2c_algo,
- .algo_data = NULL,
- .nr = 0,
- .name = "CNS3xxx I2C 0",
- .retries = 5,
-};
-
-static void cns3xxx_i2c_adapter_init(struct cns3xxx_i2c *i2c)
-{
- struct clk *clk;
-
- clk = devm_clk_get(i2c->dev, "cpu");
- if (WARN_ON(!clk))
- return;
-
- /* Disable the I2C */
- I2C_CONTROLLER_REG = 0; /* Disabled the I2C */
-
- /* Check the Reg Dump when testing */
- I2C_TIME_OUT_REG =
- (((((clk_get_rate(clk) / (2 * CNS3xxx_I2C_CLK)) -
- 1) & 0x3FF) << 8) | (1 << 7) | 0x7F);
- I2C_TWI_OUT_DLY_REG |= 0x3;
-
- /* Enable The Interrupt */
- CNS3xxx_I2C_ENABLE_INTR();
-
- /* Clear Interrupt Status (0x2 | 0x1) */
- I2C_INTERRUPT_STATUS_REG |= (I2C_ACTION_DONE_FLAG | I2C_BUS_ERROR_FLAG);
-
- /* Enable the I2C Controller */
- CNS3xxx_I2C_ENABLE();
-}
-
-static irqreturn_t cns3xxx_i2c_isr(int irq, void *dev_id)
-{
- struct cns3xxx_i2c *i2c = dev_id;
- int i;
- uint32_t stat = I2C_INTERRUPT_STATUS_REG;
-
- /* Clear Interrupt */
- I2C_INTERRUPT_STATUS_REG |= 0x1;
-
- if (stat & I2C_BUS_ERROR_FLAG) {
- i2c->state = STATE_ERROR;
- i2c->error = (I2C_INTERRUPT_STATUS_REG & 0xff00)>>8;
- } else {
- if (i2c->msg->flags & I2C_M_RD) {
- for (i = 0; i <= i2c->rd_wr_len; i++)
- {
- *i2c->buf++ = ((I2C_READ_DATA_REG >> (8 * i)) & 0xff);
- }
- }
- i2c->state = STATE_DONE;
- }
- wake_up(&i2c->wait);
- return IRQ_HANDLED;
-}
-
-static int cns3xxx_i2c_probe(struct platform_device *pdev)
-{
- struct cns3xxx_i2c *i2c;
- struct resource *res, *res2;
- int ret;
-
- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (!res) {
- printk("%s: IORESOURCE_MEM not defined \n", __FUNCTION__);
- return -ENODEV;
- }
-
- res2 = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
- if (!res2) {
- printk("%s: IORESOURCE_IRQ not defined \n", __FUNCTION__);
- return -ENODEV;
- }
-
- i2c = kzalloc(sizeof(*i2c), GFP_KERNEL);
- if (!i2c)
- return -ENOMEM;
-
- if (!request_mem_region(res->start, res->end - res->start + 1,
- pdev->name)) {
- dev_err(&pdev->dev, "Memory region busy\n");
- ret = -EBUSY;
- goto request_mem_failed;
- }
-
- i2c->dev = &pdev->dev;
- i2c->base = ioremap(res->start, res->end - res->start + 1);
- if (!i2c->base) {
- dev_err(&pdev->dev, "Unable to map registers\n");
- ret = -EIO;
- goto map_failed;
- }
-
- cns3xxx_i2c_adapter_init(i2c);
-
- init_waitqueue_head(&i2c->wait);
- ret = request_irq(res2->start, cns3xxx_i2c_isr, 0, pdev->name, i2c);
- if (ret) {
- dev_err(&pdev->dev, "Cannot claim IRQ\n");
- goto request_irq_failed;
- }
-
- platform_set_drvdata(pdev, i2c);
- i2c->adap = cns3xxx_i2c_adapter;
- i2c_set_adapdata(&i2c->adap, i2c);
- i2c->adap.dev.parent = &pdev->dev;
-
- /* add i2c adapter to i2c tree */
- ret = i2c_add_numbered_adapter(&i2c->adap);
- if (ret) {
- dev_err(&pdev->dev, "Failed to add adapter\n");
- goto add_adapter_failed;
- }
-
- return 0;
-
- add_adapter_failed:
- free_irq(res2->start, i2c);
- request_irq_failed:
- iounmap(i2c->base);
- map_failed:
- release_mem_region(res->start, res->end - res->start + 1);
- request_mem_failed:
- kfree(i2c);
-
- return ret;
-}
-
-static int cns3xxx_i2c_remove(struct platform_device *pdev)
-{
- struct cns3xxx_i2c *i2c = platform_get_drvdata(pdev);
- struct resource *res;
-
- /* disable i2c logic */
- CNS3xxx_I2C_DISABLE_INTR();
- CNS3xxx_I2C_DISABLE();
- /* remove adapter & data */
- i2c_del_adapter(&i2c->adap);
- platform_set_drvdata(pdev, NULL);
-
- res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
- if (res)
- free_irq(res->start, i2c);
-
- iounmap(i2c->base);
-
- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (res)
- release_mem_region(res->start, res->end - res->start + 1);
-
- kfree(i2c);
-
- return 0;
-}
-
-static struct platform_driver cns3xxx_i2c_driver = {
- .probe = cns3xxx_i2c_probe,
- .remove = cns3xxx_i2c_remove,
- .driver = {
- .owner = THIS_MODULE,
- .name = "cns3xxx-i2c",
- },
-};
-
-static int __init cns3xxx_i2c_init(void)
-{
- return platform_driver_register(&cns3xxx_i2c_driver);
-}
-
-static void __exit cns3xxx_i2c_exit(void)
-{
- platform_driver_unregister(&cns3xxx_i2c_driver);
-}
-
-module_init(cns3xxx_i2c_init);
-module_exit(cns3xxx_i2c_exit);
-
-MODULE_AUTHOR("Cavium Networks");
-MODULE_DESCRIPTION("Cavium CNS3XXX I2C Controller");
-MODULE_LICENSE("GPL");
projects / openwrt / staging / mkresin.git / blobdiff