diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-iop3xx.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-iop3xx.c | 553 |
1 files changed, 553 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-iop3xx.c b/drivers/i2c/busses/i2c-iop3xx.c new file mode 100644 index 0000000..fc2714a --- /dev/null +++ b/drivers/i2c/busses/i2c-iop3xx.c @@ -0,0 +1,553 @@ +/* ------------------------------------------------------------------------- */ +/* i2c-iop3xx.c i2c driver algorithms for Intel XScale IOP3xx & IXP46x */ +/* ------------------------------------------------------------------------- */ +/* Copyright (C) 2003 Peter Milne, D-TACQ Solutions Ltd + * <Peter dot Milne at D hyphen TACQ dot com> + * + * With acknowledgements to i2c-algo-ibm_ocp.c by + * Ian DaSilva, MontaVista Software, Inc. idasilva@mvista.com + * + * And i2c-algo-pcf.c, which was created by Simon G. Vogl and Hans Berglund: + * + * Copyright (C) 1995-1997 Simon G. Vogl, 1998-2000 Hans Berglund + * + * And which acknowledged Kyösti Mälkki <kmalkki@cc.hut.fi>, + * Frodo Looijaard <frodol@dds.nl>, Martin Bailey<mbailey@littlefeet-inc.com> + * + * Major cleanup by Deepak Saxena <dsaxena@plexity.net>, 01/2005: + * + * - Use driver model to pass per-chip info instead of hardcoding and #ifdefs + * - Use ioremap/__raw_readl/__raw_writel instead of direct dereference + * - Make it work with IXP46x chips + * - Cleanup function names, coding style, etc + * + * - writing to slave address causes latchup on iop331. + * fix: driver refuses to address self. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, version 2. + */ + +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/delay.h> +#include <linux/slab.h> +#include <linux/init.h> +#include <linux/errno.h> +#include <linux/platform_device.h> +#include <linux/i2c.h> + +#include <asm/io.h> + +#include "i2c-iop3xx.h" + +/* global unit counter */ +static int i2c_id; + +static inline unsigned char +iic_cook_addr(struct i2c_msg *msg) +{ + unsigned char addr; + + addr = (msg->addr << 1); + + if (msg->flags & I2C_M_RD) + addr |= 1; + + /* + * Read or Write? + */ + if (msg->flags & I2C_M_REV_DIR_ADDR) + addr ^= 1; + + return addr; +} + +static void +iop3xx_i2c_reset(struct i2c_algo_iop3xx_data *iop3xx_adap) +{ + /* Follows devman 9.3 */ + __raw_writel(IOP3XX_ICR_UNIT_RESET, iop3xx_adap->ioaddr + CR_OFFSET); + __raw_writel(IOP3XX_ISR_CLEARBITS, iop3xx_adap->ioaddr + SR_OFFSET); + __raw_writel(0, iop3xx_adap->ioaddr + CR_OFFSET); +} + +static void +iop3xx_i2c_enable(struct i2c_algo_iop3xx_data *iop3xx_adap) +{ + u32 cr = IOP3XX_ICR_GCD | IOP3XX_ICR_SCLEN | IOP3XX_ICR_UE; + + /* + * Every time unit enable is asserted, GPOD needs to be cleared + * on IOP3XX to avoid data corruption on the bus. + */ +#if defined(CONFIG_ARCH_IOP32X) || defined(CONFIG_ARCH_IOP33X) + if (iop3xx_adap->id == 0) { + gpio_line_set(IOP3XX_GPIO_LINE(7), GPIO_LOW); + gpio_line_set(IOP3XX_GPIO_LINE(6), GPIO_LOW); + } else { + gpio_line_set(IOP3XX_GPIO_LINE(5), GPIO_LOW); + gpio_line_set(IOP3XX_GPIO_LINE(4), GPIO_LOW); + } +#endif + /* NB SR bits not same position as CR IE bits :-( */ + iop3xx_adap->SR_enabled = + IOP3XX_ISR_ALD | IOP3XX_ISR_BERRD | + IOP3XX_ISR_RXFULL | IOP3XX_ISR_TXEMPTY; + + cr |= IOP3XX_ICR_ALD_IE | IOP3XX_ICR_BERR_IE | + IOP3XX_ICR_RXFULL_IE | IOP3XX_ICR_TXEMPTY_IE; + + __raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET); +} + +static void +iop3xx_i2c_transaction_cleanup(struct i2c_algo_iop3xx_data *iop3xx_adap) +{ + unsigned long cr = __raw_readl(iop3xx_adap->ioaddr + CR_OFFSET); + + cr &= ~(IOP3XX_ICR_MSTART | IOP3XX_ICR_TBYTE | + IOP3XX_ICR_MSTOP | IOP3XX_ICR_SCLEN); + + __raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET); +} + +/* + * NB: the handler has to clear the source of the interrupt! + * Then it passes the SR flags of interest to BH via adap data + */ +static irqreturn_t +iop3xx_i2c_irq_handler(int this_irq, void *dev_id) +{ + struct i2c_algo_iop3xx_data *iop3xx_adap = dev_id; + u32 sr = __raw_readl(iop3xx_adap->ioaddr + SR_OFFSET); + + if ((sr &= iop3xx_adap->SR_enabled)) { + __raw_writel(sr, iop3xx_adap->ioaddr + SR_OFFSET); + iop3xx_adap->SR_received |= sr; + wake_up_interruptible(&iop3xx_adap->waitq); + } + return IRQ_HANDLED; +} + +/* check all error conditions, clear them , report most important */ +static int +iop3xx_i2c_error(u32 sr) +{ + int rc = 0; + + if ((sr & IOP3XX_ISR_BERRD)) { + if ( !rc ) rc = -I2C_ERR_BERR; + } + if ((sr & IOP3XX_ISR_ALD)) { + if ( !rc ) rc = -I2C_ERR_ALD; + } + return rc; +} + +static inline u32 +iop3xx_i2c_get_srstat(struct i2c_algo_iop3xx_data *iop3xx_adap) +{ + unsigned long flags; + u32 sr; + + spin_lock_irqsave(&iop3xx_adap->lock, flags); + sr = iop3xx_adap->SR_received; + iop3xx_adap->SR_received = 0; + spin_unlock_irqrestore(&iop3xx_adap->lock, flags); + + return sr; +} + +/* + * sleep until interrupted, then recover and analyse the SR + * saved by handler + */ +typedef int (* compare_func)(unsigned test, unsigned mask); +/* returns 1 on correct comparison */ + +static int +iop3xx_i2c_wait_event(struct i2c_algo_iop3xx_data *iop3xx_adap, + unsigned flags, unsigned* status, + compare_func compare) +{ + unsigned sr = 0; + int interrupted; + int done; + int rc = 0; + + do { + interrupted = wait_event_interruptible_timeout ( + iop3xx_adap->waitq, + (done = compare( sr = iop3xx_i2c_get_srstat(iop3xx_adap) ,flags )), + 1 * HZ; + ); + if ((rc = iop3xx_i2c_error(sr)) < 0) { + *status = sr; + return rc; + } else if (!interrupted) { + *status = sr; + return -ETIMEDOUT; + } + } while(!done); + + *status = sr; + + return 0; +} + +/* + * Concrete compare_funcs + */ +static int +all_bits_clear(unsigned test, unsigned mask) +{ + return (test & mask) == 0; +} + +static int +any_bits_set(unsigned test, unsigned mask) +{ + return (test & mask) != 0; +} + +static int +iop3xx_i2c_wait_tx_done(struct i2c_algo_iop3xx_data *iop3xx_adap, int *status) +{ + return iop3xx_i2c_wait_event( + iop3xx_adap, + IOP3XX_ISR_TXEMPTY | IOP3XX_ISR_ALD | IOP3XX_ISR_BERRD, + status, any_bits_set); +} + +static int +iop3xx_i2c_wait_rx_done(struct i2c_algo_iop3xx_data *iop3xx_adap, int *status) +{ + return iop3xx_i2c_wait_event( + iop3xx_adap, + IOP3XX_ISR_RXFULL | IOP3XX_ISR_ALD | IOP3XX_ISR_BERRD, + status, any_bits_set); +} + +static int +iop3xx_i2c_wait_idle(struct i2c_algo_iop3xx_data *iop3xx_adap, int *status) +{ + return iop3xx_i2c_wait_event( + iop3xx_adap, IOP3XX_ISR_UNITBUSY, status, all_bits_clear); +} + +static int +iop3xx_i2c_send_target_addr(struct i2c_algo_iop3xx_data *iop3xx_adap, + struct i2c_msg* msg) +{ + unsigned long cr = __raw_readl(iop3xx_adap->ioaddr + CR_OFFSET); + int status; + int rc; + + /* avoid writing to my slave address (hangs on 80331), + * forbidden in Intel developer manual + */ + if (msg->addr == MYSAR) { + return -EBUSY; + } + + __raw_writel(iic_cook_addr(msg), iop3xx_adap->ioaddr + DBR_OFFSET); + + cr &= ~(IOP3XX_ICR_MSTOP | IOP3XX_ICR_NACK); + cr |= IOP3XX_ICR_MSTART | IOP3XX_ICR_TBYTE; + + __raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET); + rc = iop3xx_i2c_wait_tx_done(iop3xx_adap, &status); + + return rc; +} + +static int +iop3xx_i2c_write_byte(struct i2c_algo_iop3xx_data *iop3xx_adap, char byte, + int stop) +{ + unsigned long cr = __raw_readl(iop3xx_adap->ioaddr + CR_OFFSET); + int status; + int rc = 0; + + __raw_writel(byte, iop3xx_adap->ioaddr + DBR_OFFSET); + cr &= ~IOP3XX_ICR_MSTART; + if (stop) { + cr |= IOP3XX_ICR_MSTOP; + } else { + cr &= ~IOP3XX_ICR_MSTOP; + } + cr |= IOP3XX_ICR_TBYTE; + __raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET); + rc = iop3xx_i2c_wait_tx_done(iop3xx_adap, &status); + + return rc; +} + +static int +iop3xx_i2c_read_byte(struct i2c_algo_iop3xx_data *iop3xx_adap, char* byte, + int stop) +{ + unsigned long cr = __raw_readl(iop3xx_adap->ioaddr + CR_OFFSET); + int status; + int rc = 0; + + cr &= ~IOP3XX_ICR_MSTART; + + if (stop) { + cr |= IOP3XX_ICR_MSTOP | IOP3XX_ICR_NACK; + } else { + cr &= ~(IOP3XX_ICR_MSTOP | IOP3XX_ICR_NACK); + } + cr |= IOP3XX_ICR_TBYTE; + __raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET); + + rc = iop3xx_i2c_wait_rx_done(iop3xx_adap, &status); + + *byte = __raw_readl(iop3xx_adap->ioaddr + DBR_OFFSET); + + return rc; +} + +static int +iop3xx_i2c_writebytes(struct i2c_adapter *i2c_adap, const char *buf, int count) +{ + struct i2c_algo_iop3xx_data *iop3xx_adap = i2c_adap->algo_data; + int ii; + int rc = 0; + + for (ii = 0; rc == 0 && ii != count; ++ii) + rc = iop3xx_i2c_write_byte(iop3xx_adap, buf[ii], ii==count-1); + return rc; +} + +static int +iop3xx_i2c_readbytes(struct i2c_adapter *i2c_adap, char *buf, int count) +{ + struct i2c_algo_iop3xx_data *iop3xx_adap = i2c_adap->algo_data; + int ii; + int rc = 0; + + for (ii = 0; rc == 0 && ii != count; ++ii) + rc = iop3xx_i2c_read_byte(iop3xx_adap, &buf[ii], ii==count-1); + + return rc; +} + +/* + * Description: This function implements combined transactions. Combined + * transactions consist of combinations of reading and writing blocks of data. + * FROM THE SAME ADDRESS + * Each transfer (i.e. a read or a write) is separated by a repeated start + * condition. + */ +static int +iop3xx_i2c_handle_msg(struct i2c_adapter *i2c_adap, struct i2c_msg* pmsg) +{ + struct i2c_algo_iop3xx_data *iop3xx_adap = i2c_adap->algo_data; + int rc; + + rc = iop3xx_i2c_send_target_addr(iop3xx_adap, pmsg); + if (rc < 0) { + return rc; + } + + if ((pmsg->flags&I2C_M_RD)) { + return iop3xx_i2c_readbytes(i2c_adap, pmsg->buf, pmsg->len); + } else { + return iop3xx_i2c_writebytes(i2c_adap, pmsg->buf, pmsg->len); + } +} + +/* + * master_xfer() - main read/write entry + */ +static int +iop3xx_i2c_master_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, + int num) +{ + struct i2c_algo_iop3xx_data *iop3xx_adap = i2c_adap->algo_data; + int im = 0; + int ret = 0; + int status; + + iop3xx_i2c_wait_idle(iop3xx_adap, &status); + iop3xx_i2c_reset(iop3xx_adap); + iop3xx_i2c_enable(iop3xx_adap); + + for (im = 0; ret == 0 && im != num; im++) { + ret = iop3xx_i2c_handle_msg(i2c_adap, &msgs[im]); + } + + iop3xx_i2c_transaction_cleanup(iop3xx_adap); + + if(ret) + return ret; + + return im; +} + +static u32 +iop3xx_i2c_func(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; +} + +static const struct i2c_algorithm iop3xx_i2c_algo = { + .master_xfer = iop3xx_i2c_master_xfer, + .functionality = iop3xx_i2c_func, +}; + +static int +iop3xx_i2c_remove(struct platform_device *pdev) +{ + struct i2c_adapter *padapter = platform_get_drvdata(pdev); + struct i2c_algo_iop3xx_data *adapter_data = + (struct i2c_algo_iop3xx_data *)padapter->algo_data; + struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + unsigned long cr = __raw_readl(adapter_data->ioaddr + CR_OFFSET); + + /* + * Disable the actual HW unit + */ + cr &= ~(IOP3XX_ICR_ALD_IE | IOP3XX_ICR_BERR_IE | + IOP3XX_ICR_RXFULL_IE | IOP3XX_ICR_TXEMPTY_IE); + __raw_writel(cr, adapter_data->ioaddr + CR_OFFSET); + + iounmap((void __iomem*)adapter_data->ioaddr); + release_mem_region(res->start, IOP3XX_I2C_IO_SIZE); + kfree(adapter_data); + kfree(padapter); + + platform_set_drvdata(pdev, NULL); + + return 0; +} + +static int +iop3xx_i2c_probe(struct platform_device *pdev) +{ + struct resource *res; + int ret, irq; + struct i2c_adapter *new_adapter; + struct i2c_algo_iop3xx_data *adapter_data; + + new_adapter = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL); + if (!new_adapter) { + ret = -ENOMEM; + goto out; + } + + adapter_data = kzalloc(sizeof(struct i2c_algo_iop3xx_data), GFP_KERNEL); + if (!adapter_data) { + ret = -ENOMEM; + goto free_adapter; + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) { + ret = -ENODEV; + goto free_both; + } + + if (!request_mem_region(res->start, IOP3XX_I2C_IO_SIZE, pdev->name)) { + ret = -EBUSY; + goto free_both; + } + + /* set the adapter enumeration # */ + adapter_data->id = i2c_id++; + + adapter_data->ioaddr = (u32)ioremap(res->start, IOP3XX_I2C_IO_SIZE); + if (!adapter_data->ioaddr) { + ret = -ENOMEM; + goto release_region; + } + + irq = platform_get_irq(pdev, 0); + if (irq < 0) { + ret = -ENXIO; + goto unmap; + } + ret = request_irq(irq, iop3xx_i2c_irq_handler, 0, + pdev->name, adapter_data); + + if (ret) { + ret = -EIO; + goto unmap; + } + + memcpy(new_adapter->name, pdev->name, strlen(pdev->name)); + new_adapter->id = I2C_HW_IOP3XX; + new_adapter->owner = THIS_MODULE; + new_adapter->class = I2C_CLASS_HWMON | I2C_CLASS_SPD; + new_adapter->dev.parent = &pdev->dev; + new_adapter->nr = pdev->id; + + /* + * Default values...should these come in from board code? + */ + new_adapter->timeout = 100; + new_adapter->algo = &iop3xx_i2c_algo; + + init_waitqueue_head(&adapter_data->waitq); + spin_lock_init(&adapter_data->lock); + + iop3xx_i2c_reset(adapter_data); + iop3xx_i2c_enable(adapter_data); + + platform_set_drvdata(pdev, new_adapter); + new_adapter->algo_data = adapter_data; + + i2c_add_numbered_adapter(new_adapter); + + return 0; + +unmap: + iounmap((void __iomem*)adapter_data->ioaddr); + +release_region: + release_mem_region(res->start, IOP3XX_I2C_IO_SIZE); + +free_both: + kfree(adapter_data); + +free_adapter: + kfree(new_adapter); + +out: + return ret; +} + + +static struct platform_driver iop3xx_i2c_driver = { + .probe = iop3xx_i2c_probe, + .remove = iop3xx_i2c_remove, + .driver = { + .owner = THIS_MODULE, + .name = "IOP3xx-I2C", + }, +}; + +static int __init +i2c_iop3xx_init (void) +{ + return platform_driver_register(&iop3xx_i2c_driver); +} + +static void __exit +i2c_iop3xx_exit (void) +{ + platform_driver_unregister(&iop3xx_i2c_driver); + return; +} + +module_init (i2c_iop3xx_init); +module_exit (i2c_iop3xx_exit); + +MODULE_AUTHOR("D-TACQ Solutions Ltd <www.d-tacq.com>"); +MODULE_DESCRIPTION("IOP3xx iic algorithm and driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:IOP3xx-I2C"); |
