change from original version -- by advice of Jean Delvare 1. remove global variable i2c_reg, replaced by local variables 2. replace ENXIO with ENODEV when no platform resources 3. add adapter->nr assignment before i2c_add_numbered_adapter() call 4. add judgement for i2c_del_adapter() return value 5. release adapter when driver removed 6. add __devexit for puv3_i2c_remove() function 7. modify several names to more appropriated ones Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn> Acked-by: Arnd Bergmann <arnd@arndb.de>tirimbino
GuanXuetao
14 years ago
parent
e5abf78b57
commit
d10e4a660d
@ -0,0 +1,306 @@ |
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/*
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* I2C driver for PKUnity-v3 SoC |
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* Code specific to PKUnity SoC and UniCore ISA |
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* |
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* Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn> |
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* Copyright (C) 2001-2010 Guan Xuetao |
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* |
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* This program is free software; you can redistribute it and/or modify |
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* it under the terms of the GNU General Public License version 2 as |
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* published by the Free Software Foundation. |
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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/err.h> |
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#include <linux/slab.h> |
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#include <linux/types.h> |
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#include <linux/delay.h> |
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#include <linux/i2c.h> |
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#include <linux/init.h> |
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#include <linux/clk.h> |
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#include <linux/platform_device.h> |
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#include <linux/io.h> |
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#include <mach/hardware.h> |
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/*
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* Poll the i2c status register until the specified bit is set. |
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* Returns 0 if timed out (100 msec). |
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*/ |
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static short poll_status(unsigned long bit) |
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{ |
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int loop_cntr = 1000; |
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if (bit & I2C_STATUS_TFNF) { |
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do { |
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udelay(10); |
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} while (!(readl(I2C_STATUS) & bit) && (--loop_cntr > 0)); |
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} else { |
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/* RXRDY handler */ |
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do { |
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if (readl(I2C_TAR) == I2C_TAR_EEPROM) |
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msleep(20); |
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else |
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udelay(10); |
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} while (!(readl(I2C_RXFLR) & 0xf) && (--loop_cntr > 0)); |
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} |
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return (loop_cntr > 0); |
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} |
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static int xfer_read(struct i2c_adapter *adap, unsigned char *buf, int length) |
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{ |
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int i2c_reg = *buf; |
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/* Read data */ |
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while (length--) { |
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if (!poll_status(I2C_STATUS_TFNF)) { |
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dev_dbg(&adap->dev, "Tx FIFO Not Full timeout\n"); |
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return -ETIMEDOUT; |
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} |
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/* send addr */ |
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writel(i2c_reg | I2C_DATACMD_WRITE, I2C_DATACMD); |
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/* get ready to next write */ |
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i2c_reg++; |
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/* send read CMD */ |
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writel(I2C_DATACMD_READ, I2C_DATACMD); |
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/* wait until the Rx FIFO have available */ |
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if (!poll_status(I2C_STATUS_RFNE)) { |
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dev_dbg(&adap->dev, "RXRDY timeout\n"); |
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return -ETIMEDOUT; |
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} |
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/* read the data to buf */ |
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*buf = (readl(I2C_DATACMD) & I2C_DATACMD_DAT_MASK); |
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buf++; |
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} |
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return 0; |
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} |
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static int xfer_write(struct i2c_adapter *adap, unsigned char *buf, int length) |
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{ |
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int i2c_reg = *buf; |
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/* Do nothing but storing the reg_num to a static variable */ |
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if (i2c_reg == -1) { |
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printk(KERN_WARNING "Error i2c reg\n"); |
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return -ETIMEDOUT; |
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} |
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if (length == 1) |
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return 0; |
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buf++; |
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length--; |
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while (length--) { |
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/* send addr */ |
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writel(i2c_reg | I2C_DATACMD_WRITE, I2C_DATACMD); |
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/* send write CMD */ |
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writel(*buf | I2C_DATACMD_WRITE, I2C_DATACMD); |
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/* wait until the Rx FIFO have available */ |
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msleep(20); |
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/* read the data to buf */ |
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i2c_reg++; |
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buf++; |
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} |
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return 0; |
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} |
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/*
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* Generic i2c master transfer entrypoint. |
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* |
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*/ |
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static int puv3_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *pmsg, |
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int num) |
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{ |
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int i, ret; |
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unsigned char swap; |
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/* Disable i2c */ |
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writel(I2C_ENABLE_DISABLE, I2C_ENABLE); |
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/* Set the work mode and speed*/ |
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writel(I2C_CON_MASTER | I2C_CON_SPEED_STD | I2C_CON_SLAVEDISABLE, I2C_CON); |
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writel(pmsg->addr, I2C_TAR); |
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/* Enable i2c */ |
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writel(I2C_ENABLE_ENABLE, I2C_ENABLE); |
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dev_dbg(&adap->dev, "puv3_i2c_xfer: processing %d messages:\n", num); |
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for (i = 0; i < num; i++) { |
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dev_dbg(&adap->dev, " #%d: %sing %d byte%s %s 0x%02x\n", i, |
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pmsg->flags & I2C_M_RD ? "read" : "writ", |
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pmsg->len, pmsg->len > 1 ? "s" : "", |
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pmsg->flags & I2C_M_RD ? "from" : "to", pmsg->addr); |
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if (pmsg->len && pmsg->buf) { /* sanity check */ |
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if (pmsg->flags & I2C_M_RD) |
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ret = xfer_read(adap, pmsg->buf, pmsg->len); |
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else |
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ret = xfer_write(adap, pmsg->buf, pmsg->len); |
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if (ret) |
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return ret; |
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} |
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dev_dbg(&adap->dev, "transfer complete\n"); |
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pmsg++; /* next message */ |
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} |
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/* XXX: fixup be16_to_cpu in bq27x00_battery.c */ |
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if (pmsg->addr == I2C_TAR_PWIC) { |
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swap = pmsg->buf[0]; |
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pmsg->buf[0] = pmsg->buf[1]; |
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pmsg->buf[1] = swap; |
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} |
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return i; |
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} |
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/*
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* Return list of supported functionality. |
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*/ |
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static u32 puv3_i2c_func(struct i2c_adapter *adapter) |
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{ |
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return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; |
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} |
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static struct i2c_algorithm puv3_i2c_algorithm = { |
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.master_xfer = puv3_i2c_xfer, |
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.functionality = puv3_i2c_func, |
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}; |
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/*
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* Main initialization routine. |
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*/ |
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static int __devinit puv3_i2c_probe(struct platform_device *pdev) |
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{ |
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struct i2c_adapter *adapter; |
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struct resource *mem; |
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int rc; |
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mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
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if (!mem) |
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return -ENODEV; |
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if (!request_mem_region(mem->start, resource_size(mem), "puv3_i2c")) |
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return -EBUSY; |
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adapter = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL); |
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if (adapter == NULL) { |
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dev_err(&pdev->dev, "can't allocate inteface!\n"); |
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rc = -ENOMEM; |
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goto fail_nomem; |
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} |
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snprintf(adapter->name, sizeof(adapter->name), "PUV3-I2C at 0x%08x", |
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mem->start); |
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adapter->algo = &puv3_i2c_algorithm; |
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adapter->class = I2C_CLASS_HWMON; |
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adapter->dev.parent = &pdev->dev; |
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platform_set_drvdata(pdev, adapter); |
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adapter->nr = pdev->id; |
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rc = i2c_add_numbered_adapter(adapter); |
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if (rc) { |
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dev_err(&pdev->dev, "Adapter '%s' registration failed\n", |
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adapter->name); |
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goto fail_add_adapter; |
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} |
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dev_info(&pdev->dev, "PKUnity v3 i2c bus adapter.\n"); |
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return 0; |
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fail_add_adapter: |
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platform_set_drvdata(pdev, NULL); |
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kfree(adapter); |
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fail_nomem: |
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release_mem_region(mem->start, resource_size(mem)); |
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return rc; |
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} |
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static int __devexit puv3_i2c_remove(struct platform_device *pdev) |
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{ |
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struct i2c_adapter *adapter = platform_get_drvdata(pdev); |
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struct resource *mem; |
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int rc; |
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rc = i2c_del_adapter(adapter); |
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if (rc) { |
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dev_err(&pdev->dev, "Adapter '%s' delete fail\n", |
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adapter->name); |
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return rc; |
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} |
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put_device(&pdev->dev); |
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platform_set_drvdata(pdev, NULL); |
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mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
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release_mem_region(mem->start, resource_size(mem)); |
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return rc; |
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} |
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#ifdef CONFIG_PM |
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static int puv3_i2c_suspend(struct platform_device *dev, pm_message_t state) |
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{ |
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int poll_count; |
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/* Disable the IIC */ |
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writel(I2C_ENABLE_DISABLE, I2C_ENABLE); |
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for (poll_count = 0; poll_count < 50; poll_count++) { |
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if (readl(I2C_ENSTATUS) & I2C_ENSTATUS_ENABLE) |
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udelay(25); |
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} |
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return 0; |
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} |
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static int puv3_i2c_resume(struct platform_device *dev) |
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{ |
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return 0 ; |
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} |
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#else |
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#define puv3_i2c_suspend NULL |
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#define puv3_i2c_resume NULL |
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#endif |
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MODULE_ALIAS("platform:puv3_i2c"); |
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static struct platform_driver puv3_i2c_driver = { |
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.probe = puv3_i2c_probe, |
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.remove = __devexit_p(puv3_i2c_remove), |
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.suspend = puv3_i2c_suspend, |
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.resume = puv3_i2c_resume, |
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.driver = { |
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.name = "PKUnity-v3-I2C", |
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.owner = THIS_MODULE, |
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} |
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}; |
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static int __init puv3_i2c_init(void) |
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{ |
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return platform_driver_register(&puv3_i2c_driver); |
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} |
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static void __exit puv3_i2c_exit(void) |
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{ |
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platform_driver_unregister(&puv3_i2c_driver); |
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} |
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module_init(puv3_i2c_init); |
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module_exit(puv3_i2c_exit); |
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MODULE_DESCRIPTION("PKUnity v3 I2C driver"); |
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MODULE_LICENSE("GPL v2"); |
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