| /* |
| * I2C driver for PKUnity-v3 SoC |
| * Code specific to PKUnity SoC and UniCore ISA |
| * |
| * Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn> |
| * Copyright (C) 2001-2010 Guan Xuetao |
| * |
| * This program 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/module.h> |
| #include <linux/kernel.h> |
| #include <linux/err.h> |
| #include <linux/slab.h> |
| #include <linux/types.h> |
| #include <linux/delay.h> |
| #include <linux/i2c.h> |
| #include <linux/init.h> |
| #include <linux/clk.h> |
| #include <linux/platform_device.h> |
| #include <linux/io.h> |
| #include <mach/hardware.h> |
| |
| /* |
| * Poll the i2c status register until the specified bit is set. |
| * Returns 0 if timed out (100 msec). |
| */ |
| static short poll_status(unsigned long bit) |
| { |
| int loop_cntr = 1000; |
| |
| if (bit & I2C_STATUS_TFNF) { |
| do { |
| udelay(10); |
| } while (!(readl(I2C_STATUS) & bit) && (--loop_cntr > 0)); |
| } else { |
| /* RXRDY handler */ |
| do { |
| if (readl(I2C_TAR) == I2C_TAR_EEPROM) |
| msleep(20); |
| else |
| udelay(10); |
| } while (!(readl(I2C_RXFLR) & 0xf) && (--loop_cntr > 0)); |
| } |
| |
| return (loop_cntr > 0); |
| } |
| |
| static int xfer_read(struct i2c_adapter *adap, unsigned char *buf, int length) |
| { |
| int i2c_reg = *buf; |
| |
| /* Read data */ |
| while (length--) { |
| if (!poll_status(I2C_STATUS_TFNF)) { |
| dev_dbg(&adap->dev, "Tx FIFO Not Full timeout\n"); |
| return -ETIMEDOUT; |
| } |
| |
| /* send addr */ |
| writel(i2c_reg | I2C_DATACMD_WRITE, I2C_DATACMD); |
| |
| /* get ready to next write */ |
| i2c_reg++; |
| |
| /* send read CMD */ |
| writel(I2C_DATACMD_READ, I2C_DATACMD); |
| |
| /* wait until the Rx FIFO have available */ |
| if (!poll_status(I2C_STATUS_RFNE)) { |
| dev_dbg(&adap->dev, "RXRDY timeout\n"); |
| return -ETIMEDOUT; |
| } |
| |
| /* read the data to buf */ |
| *buf = (readl(I2C_DATACMD) & I2C_DATACMD_DAT_MASK); |
| buf++; |
| } |
| |
| return 0; |
| } |
| |
| static int xfer_write(struct i2c_adapter *adap, unsigned char *buf, int length) |
| { |
| int i2c_reg = *buf; |
| |
| /* Do nothing but storing the reg_num to a static variable */ |
| if (i2c_reg == -1) { |
| printk(KERN_WARNING "Error i2c reg\n"); |
| return -ETIMEDOUT; |
| } |
| |
| if (length == 1) |
| return 0; |
| |
| buf++; |
| length--; |
| while (length--) { |
| /* send addr */ |
| writel(i2c_reg | I2C_DATACMD_WRITE, I2C_DATACMD); |
| |
| /* send write CMD */ |
| writel(*buf | I2C_DATACMD_WRITE, I2C_DATACMD); |
| |
| /* wait until the Rx FIFO have available */ |
| msleep(20); |
| |
| /* read the data to buf */ |
| i2c_reg++; |
| buf++; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * Generic i2c master transfer entrypoint. |
| * |
| */ |
| static int puv3_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *pmsg, |
| int num) |
| { |
| int i, ret; |
| unsigned char swap; |
| |
| /* Disable i2c */ |
| writel(I2C_ENABLE_DISABLE, I2C_ENABLE); |
| |
| /* Set the work mode and speed*/ |
| writel(I2C_CON_MASTER | I2C_CON_SPEED_STD | I2C_CON_SLAVEDISABLE, I2C_CON); |
| |
| writel(pmsg->addr, I2C_TAR); |
| |
| /* Enable i2c */ |
| writel(I2C_ENABLE_ENABLE, I2C_ENABLE); |
| |
| dev_dbg(&adap->dev, "puv3_i2c_xfer: processing %d messages:\n", num); |
| |
| for (i = 0; i < num; i++) { |
| dev_dbg(&adap->dev, " #%d: %sing %d byte%s %s 0x%02x\n", i, |
| pmsg->flags & I2C_M_RD ? "read" : "writ", |
| pmsg->len, pmsg->len > 1 ? "s" : "", |
| pmsg->flags & I2C_M_RD ? "from" : "to", pmsg->addr); |
| |
| if (pmsg->len && pmsg->buf) { /* sanity check */ |
| if (pmsg->flags & I2C_M_RD) |
| ret = xfer_read(adap, pmsg->buf, pmsg->len); |
| else |
| ret = xfer_write(adap, pmsg->buf, pmsg->len); |
| |
| if (ret) |
| return ret; |
| |
| } |
| dev_dbg(&adap->dev, "transfer complete\n"); |
| pmsg++; /* next message */ |
| } |
| |
| /* XXX: fixup be16_to_cpu in bq27x00_battery.c */ |
| if (pmsg->addr == I2C_TAR_PWIC) { |
| swap = pmsg->buf[0]; |
| pmsg->buf[0] = pmsg->buf[1]; |
| pmsg->buf[1] = swap; |
| } |
| |
| return i; |
| } |
| |
| /* |
| * Return list of supported functionality. |
| */ |
| static u32 puv3_i2c_func(struct i2c_adapter *adapter) |
| { |
| return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; |
| } |
| |
| static struct i2c_algorithm puv3_i2c_algorithm = { |
| .master_xfer = puv3_i2c_xfer, |
| .functionality = puv3_i2c_func, |
| }; |
| |
| /* |
| * Main initialization routine. |
| */ |
| static int puv3_i2c_probe(struct platform_device *pdev) |
| { |
| struct i2c_adapter *adapter; |
| struct resource *mem; |
| int rc; |
| |
| mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| if (!mem) |
| return -ENODEV; |
| |
| if (!request_mem_region(mem->start, resource_size(mem), "puv3_i2c")) |
| return -EBUSY; |
| |
| adapter = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL); |
| if (adapter == NULL) { |
| dev_err(&pdev->dev, "can't allocate inteface!\n"); |
| rc = -ENOMEM; |
| goto fail_nomem; |
| } |
| snprintf(adapter->name, sizeof(adapter->name), "PUV3-I2C at 0x%08x", |
| mem->start); |
| adapter->algo = &puv3_i2c_algorithm; |
| adapter->class = I2C_CLASS_HWMON; |
| adapter->dev.parent = &pdev->dev; |
| |
| platform_set_drvdata(pdev, adapter); |
| |
| adapter->nr = pdev->id; |
| rc = i2c_add_numbered_adapter(adapter); |
| if (rc) { |
| dev_err(&pdev->dev, "Adapter '%s' registration failed\n", |
| adapter->name); |
| goto fail_add_adapter; |
| } |
| |
| dev_info(&pdev->dev, "PKUnity v3 i2c bus adapter.\n"); |
| return 0; |
| |
| fail_add_adapter: |
| kfree(adapter); |
| fail_nomem: |
| release_mem_region(mem->start, resource_size(mem)); |
| |
| return rc; |
| } |
| |
| static int puv3_i2c_remove(struct platform_device *pdev) |
| { |
| struct i2c_adapter *adapter = platform_get_drvdata(pdev); |
| struct resource *mem; |
| int rc; |
| |
| rc = i2c_del_adapter(adapter); |
| if (rc) { |
| dev_err(&pdev->dev, "Adapter '%s' delete fail\n", |
| adapter->name); |
| return rc; |
| } |
| |
| put_device(&pdev->dev); |
| |
| mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| release_mem_region(mem->start, resource_size(mem)); |
| |
| return rc; |
| } |
| |
| #ifdef CONFIG_PM |
| static int puv3_i2c_suspend(struct device *dev) |
| { |
| int poll_count; |
| /* Disable the IIC */ |
| writel(I2C_ENABLE_DISABLE, I2C_ENABLE); |
| for (poll_count = 0; poll_count < 50; poll_count++) { |
| if (readl(I2C_ENSTATUS) & I2C_ENSTATUS_ENABLE) |
| udelay(25); |
| } |
| |
| return 0; |
| } |
| |
| static SIMPLE_DEV_PM_OPS(puv3_i2c_pm, puv3_i2c_suspend, NULL); |
| #define PUV3_I2C_PM (&puv3_i2c_pm) |
| |
| #else |
| #define PUV3_I2C_PM NULL |
| #endif |
| |
| static struct platform_driver puv3_i2c_driver = { |
| .probe = puv3_i2c_probe, |
| .remove = puv3_i2c_remove, |
| .driver = { |
| .name = "PKUnity-v3-I2C", |
| .owner = THIS_MODULE, |
| .pm = PUV3_I2C_PM, |
| } |
| }; |
| |
| module_platform_driver(puv3_i2c_driver); |
| |
| MODULE_DESCRIPTION("PKUnity v3 I2C driver"); |
| MODULE_LICENSE("GPL v2"); |
| MODULE_ALIAS("platform:puv3_i2c"); |