diff options
Diffstat (limited to 'ANDROID_3.4.5/drivers/i2c/algos/i2c-algo-bit.c')
| -rw-r--r-- | ANDROID_3.4.5/drivers/i2c/algos/i2c-algo-bit.c | 671 |
1 files changed, 0 insertions, 671 deletions
diff --git a/ANDROID_3.4.5/drivers/i2c/algos/i2c-algo-bit.c b/ANDROID_3.4.5/drivers/i2c/algos/i2c-algo-bit.c deleted file mode 100644 index 7f0b8321..00000000 --- a/ANDROID_3.4.5/drivers/i2c/algos/i2c-algo-bit.c +++ /dev/null @@ -1,671 +0,0 @@ -/* ------------------------------------------------------------------------- - * i2c-algo-bit.c i2c driver algorithms for bit-shift adapters - * ------------------------------------------------------------------------- - * Copyright (C) 1995-2000 Simon G. Vogl - - 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; either version 2 of the License, or - (at your option) any later version. - - This program is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. - - You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software - Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, - MA 02110-1301 USA. - * ------------------------------------------------------------------------- */ - -/* With some changes from Frodo Looijaard <frodol@dds.nl>, Kyösti Mälkki - <kmalkki@cc.hut.fi> and Jean Delvare <khali@linux-fr.org> */ - -#include <linux/kernel.h> -#include <linux/module.h> -#include <linux/delay.h> -#include <linux/init.h> -#include <linux/errno.h> -#include <linux/sched.h> -#include <linux/i2c.h> -#include <linux/i2c-algo-bit.h> - - -/* ----- global defines ----------------------------------------------- */ - -#ifdef DEBUG -#define bit_dbg(level, dev, format, args...) \ - do { \ - if (i2c_debug >= level) \ - dev_dbg(dev, format, ##args); \ - } while (0) -#else -#define bit_dbg(level, dev, format, args...) \ - do {} while (0) -#endif /* DEBUG */ - -/* ----- global variables --------------------------------------------- */ - -static int bit_test; /* see if the line-setting functions work */ -module_param(bit_test, int, S_IRUGO); -MODULE_PARM_DESC(bit_test, "lines testing - 0 off; 1 report; 2 fail if stuck"); - -#ifdef DEBUG -static int i2c_debug = 1; -module_param(i2c_debug, int, S_IRUGO | S_IWUSR); -MODULE_PARM_DESC(i2c_debug, - "debug level - 0 off; 1 normal; 2 verbose; 3 very verbose"); -#endif - -/* --- setting states on the bus with the right timing: --------------- */ - -#define setsda(adap, val) adap->setsda(adap->data, val) -#define setscl(adap, val) adap->setscl(adap->data, val) -#define getsda(adap) adap->getsda(adap->data) -#define getscl(adap) adap->getscl(adap->data) - -static inline void sdalo(struct i2c_algo_bit_data *adap) -{ - setsda(adap, 0); - udelay((adap->udelay + 1) / 2); -} - -static inline void sdahi(struct i2c_algo_bit_data *adap) -{ - setsda(adap, 1); - udelay((adap->udelay + 1) / 2); -} - -static inline void scllo(struct i2c_algo_bit_data *adap) -{ - setscl(adap, 0); - udelay(adap->udelay / 2); -} - -/* - * Raise scl line, and do checking for delays. This is necessary for slower - * devices. - */ -static int sclhi(struct i2c_algo_bit_data *adap) -{ - unsigned long start; - - setscl(adap, 1); - - /* Not all adapters have scl sense line... */ - if (!adap->getscl) - goto done; - - start = jiffies; - while (!getscl(adap)) { - /* This hw knows how to read the clock line, so we wait - * until it actually gets high. This is safer as some - * chips may hold it low ("clock stretching") while they - * are processing data internally. - */ - if (time_after(jiffies, start + adap->timeout)) { - /* Test one last time, as we may have been preempted - * between last check and timeout test. - */ - if (getscl(adap)) - break; - return -ETIMEDOUT; - } - cpu_relax(); - } -#ifdef DEBUG - if (jiffies != start && i2c_debug >= 3) - pr_debug("i2c-algo-bit: needed %ld jiffies for SCL to go " - "high\n", jiffies - start); -#endif - -done: - udelay(adap->udelay); - return 0; -} - - -/* --- other auxiliary functions -------------------------------------- */ -static void i2c_start(struct i2c_algo_bit_data *adap) -{ - /* assert: scl, sda are high */ - setsda(adap, 0); - udelay(adap->udelay); - scllo(adap); -} - -static void i2c_repstart(struct i2c_algo_bit_data *adap) -{ - /* assert: scl is low */ - sdahi(adap); - sclhi(adap); - setsda(adap, 0); - udelay(adap->udelay); - scllo(adap); -} - - -static void i2c_stop(struct i2c_algo_bit_data *adap) -{ - /* assert: scl is low */ - sdalo(adap); - sclhi(adap); - setsda(adap, 1); - udelay(adap->udelay); -} - - - -/* send a byte without start cond., look for arbitration, - check ackn. from slave */ -/* returns: - * 1 if the device acknowledged - * 0 if the device did not ack - * -ETIMEDOUT if an error occurred (while raising the scl line) - */ -static int i2c_outb(struct i2c_adapter *i2c_adap, unsigned char c) -{ - int i; - int sb; - int ack; - struct i2c_algo_bit_data *adap = i2c_adap->algo_data; - - /* assert: scl is low */ - for (i = 7; i >= 0; i--) { - sb = (c >> i) & 1; - setsda(adap, sb); - udelay((adap->udelay + 1) / 2); - if (sclhi(adap) < 0) { /* timed out */ - bit_dbg(1, &i2c_adap->dev, "i2c_outb: 0x%02x, " - "timeout at bit #%d\n", (int)c, i); - return -ETIMEDOUT; - } - /* FIXME do arbitration here: - * if (sb && !getsda(adap)) -> ouch! Get out of here. - * - * Report a unique code, so higher level code can retry - * the whole (combined) message and *NOT* issue STOP. - */ - scllo(adap); - } - sdahi(adap); - if (sclhi(adap) < 0) { /* timeout */ - bit_dbg(1, &i2c_adap->dev, "i2c_outb: 0x%02x, " - "timeout at ack\n", (int)c); - return -ETIMEDOUT; - } - - /* read ack: SDA should be pulled down by slave, or it may - * NAK (usually to report problems with the data we wrote). - */ - ack = !getsda(adap); /* ack: sda is pulled low -> success */ - bit_dbg(2, &i2c_adap->dev, "i2c_outb: 0x%02x %s\n", (int)c, - ack ? "A" : "NA"); - - scllo(adap); - return ack; - /* assert: scl is low (sda undef) */ -} - - -static int i2c_inb(struct i2c_adapter *i2c_adap) -{ - /* read byte via i2c port, without start/stop sequence */ - /* acknowledge is sent in i2c_read. */ - int i; - unsigned char indata = 0; - struct i2c_algo_bit_data *adap = i2c_adap->algo_data; - - /* assert: scl is low */ - sdahi(adap); - for (i = 0; i < 8; i++) { - if (sclhi(adap) < 0) { /* timeout */ - bit_dbg(1, &i2c_adap->dev, "i2c_inb: timeout at bit " - "#%d\n", 7 - i); - return -ETIMEDOUT; - } - indata *= 2; - if (getsda(adap)) - indata |= 0x01; - setscl(adap, 0); - udelay(i == 7 ? adap->udelay / 2 : adap->udelay); - } - /* assert: scl is low */ - return indata; -} - -/* - * Sanity check for the adapter hardware - check the reaction of - * the bus lines only if it seems to be idle. - */ -static int test_bus(struct i2c_adapter *i2c_adap) -{ - struct i2c_algo_bit_data *adap = i2c_adap->algo_data; - const char *name = i2c_adap->name; - int scl, sda, ret; - - if (adap->pre_xfer) { - ret = adap->pre_xfer(i2c_adap); - if (ret < 0) - return -ENODEV; - } - - if (adap->getscl == NULL) - pr_info("%s: Testing SDA only, SCL is not readable\n", name); - - sda = getsda(adap); - scl = (adap->getscl == NULL) ? 1 : getscl(adap); - if (!scl || !sda) { - printk(KERN_WARNING - "%s: bus seems to be busy (scl=%d, sda=%d)\n", - name, scl, sda); - goto bailout; - } - - sdalo(adap); - sda = getsda(adap); - scl = (adap->getscl == NULL) ? 1 : getscl(adap); - if (sda) { - printk(KERN_WARNING "%s: SDA stuck high!\n", name); - goto bailout; - } - if (!scl) { - printk(KERN_WARNING "%s: SCL unexpected low " - "while pulling SDA low!\n", name); - goto bailout; - } - - sdahi(adap); - sda = getsda(adap); - scl = (adap->getscl == NULL) ? 1 : getscl(adap); - if (!sda) { - printk(KERN_WARNING "%s: SDA stuck low!\n", name); - goto bailout; - } - if (!scl) { - printk(KERN_WARNING "%s: SCL unexpected low " - "while pulling SDA high!\n", name); - goto bailout; - } - - scllo(adap); - sda = getsda(adap); - scl = (adap->getscl == NULL) ? 0 : getscl(adap); - if (scl) { - printk(KERN_WARNING "%s: SCL stuck high!\n", name); - goto bailout; - } - if (!sda) { - printk(KERN_WARNING "%s: SDA unexpected low " - "while pulling SCL low!\n", name); - goto bailout; - } - - sclhi(adap); - sda = getsda(adap); - scl = (adap->getscl == NULL) ? 1 : getscl(adap); - if (!scl) { - printk(KERN_WARNING "%s: SCL stuck low!\n", name); - goto bailout; - } - if (!sda) { - printk(KERN_WARNING "%s: SDA unexpected low " - "while pulling SCL high!\n", name); - goto bailout; - } - - if (adap->post_xfer) - adap->post_xfer(i2c_adap); - - pr_info("%s: Test OK\n", name); - return 0; -bailout: - sdahi(adap); - sclhi(adap); - - if (adap->post_xfer) - adap->post_xfer(i2c_adap); - - return -ENODEV; -} - -/* ----- Utility functions - */ - -/* try_address tries to contact a chip for a number of - * times before it gives up. - * return values: - * 1 chip answered - * 0 chip did not answer - * -x transmission error - */ -static int try_address(struct i2c_adapter *i2c_adap, - unsigned char addr, int retries) -{ - struct i2c_algo_bit_data *adap = i2c_adap->algo_data; - int i, ret = 0; - - for (i = 0; i <= retries; i++) { - ret = i2c_outb(i2c_adap, addr); - if (ret == 1 || i == retries) - break; - bit_dbg(3, &i2c_adap->dev, "emitting stop condition\n"); - i2c_stop(adap); - udelay(adap->udelay); - yield(); - bit_dbg(3, &i2c_adap->dev, "emitting start condition\n"); - i2c_start(adap); - } - if (i && ret) - bit_dbg(1, &i2c_adap->dev, "Used %d tries to %s client at " - "0x%02x: %s\n", i + 1, - addr & 1 ? "read from" : "write to", addr >> 1, - ret == 1 ? "success" : "failed, timeout?"); - return ret; -} - -static int sendbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) -{ - const unsigned char *temp = msg->buf; - int count = msg->len; - unsigned short nak_ok = msg->flags & I2C_M_IGNORE_NAK; - int retval; - int wrcount = 0; - - while (count > 0) { - retval = i2c_outb(i2c_adap, *temp); - - /* OK/ACK; or ignored NAK */ - if ((retval > 0) || (nak_ok && (retval == 0))) { - count--; - temp++; - wrcount++; - - /* A slave NAKing the master means the slave didn't like - * something about the data it saw. For example, maybe - * the SMBus PEC was wrong. - */ - } else if (retval == 0) { - dev_err(&i2c_adap->dev, "sendbytes: NAK bailout.\n"); - return -EIO; - - /* Timeout; or (someday) lost arbitration - * - * FIXME Lost ARB implies retrying the transaction from - * the first message, after the "winning" master issues - * its STOP. As a rule, upper layer code has no reason - * to know or care about this ... it is *NOT* an error. - */ - } else { - dev_err(&i2c_adap->dev, "sendbytes: error %d\n", - retval); - return retval; - } - } - return wrcount; -} - -static int acknak(struct i2c_adapter *i2c_adap, int is_ack) -{ - struct i2c_algo_bit_data *adap = i2c_adap->algo_data; - - /* assert: sda is high */ - if (is_ack) /* send ack */ - setsda(adap, 0); - udelay((adap->udelay + 1) / 2); - if (sclhi(adap) < 0) { /* timeout */ - dev_err(&i2c_adap->dev, "readbytes: ack/nak timeout\n"); - return -ETIMEDOUT; - } - scllo(adap); - return 0; -} - -static int readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) -{ - int inval; - int rdcount = 0; /* counts bytes read */ - unsigned char *temp = msg->buf; - int count = msg->len; - const unsigned flags = msg->flags; - - while (count > 0) { - inval = i2c_inb(i2c_adap); - if (inval >= 0) { - *temp = inval; - rdcount++; - } else { /* read timed out */ - break; - } - - temp++; - count--; - - /* Some SMBus transactions require that we receive the - transaction length as the first read byte. */ - if (rdcount == 1 && (flags & I2C_M_RECV_LEN)) { - if (inval <= 0 || inval > I2C_SMBUS_BLOCK_MAX) { - if (!(flags & I2C_M_NO_RD_ACK)) - acknak(i2c_adap, 0); - dev_err(&i2c_adap->dev, "readbytes: invalid " - "block length (%d)\n", inval); - return -EPROTO; - } - /* The original count value accounts for the extra - bytes, that is, either 1 for a regular transaction, - or 2 for a PEC transaction. */ - count += inval; - msg->len += inval; - } - - bit_dbg(2, &i2c_adap->dev, "readbytes: 0x%02x %s\n", - inval, - (flags & I2C_M_NO_RD_ACK) - ? "(no ack/nak)" - : (count ? "A" : "NA")); - - if (!(flags & I2C_M_NO_RD_ACK)) { - inval = acknak(i2c_adap, count); - if (inval < 0) - return inval; - } - } - return rdcount; -} - -/* doAddress initiates the transfer by generating the start condition (in - * try_address) and transmits the address in the necessary format to handle - * reads, writes as well as 10bit-addresses. - * returns: - * 0 everything went okay, the chip ack'ed, or IGNORE_NAK flag was set - * -x an error occurred (like: -ENXIO if the device did not answer, or - * -ETIMEDOUT, for example if the lines are stuck...) - */ -static int bit_doAddress(struct i2c_adapter *i2c_adap, struct i2c_msg *msg) -{ - unsigned short flags = msg->flags; - unsigned short nak_ok = msg->flags & I2C_M_IGNORE_NAK; - struct i2c_algo_bit_data *adap = i2c_adap->algo_data; - - unsigned char addr; - int ret, retries; - - retries = nak_ok ? 0 : i2c_adap->retries; - - if (flags & I2C_M_TEN) { - /* a ten bit address */ - addr = 0xf0 | ((msg->addr >> 7) & 0x06); - bit_dbg(2, &i2c_adap->dev, "addr0: %d\n", addr); - /* try extended address code...*/ - ret = try_address(i2c_adap, addr, retries); - if ((ret != 1) && !nak_ok) { - dev_err(&i2c_adap->dev, - "died at extended address code\n"); - return -ENXIO; - } - /* the remaining 8 bit address */ - ret = i2c_outb(i2c_adap, msg->addr & 0xff); - if ((ret != 1) && !nak_ok) { - /* the chip did not ack / xmission error occurred */ - dev_err(&i2c_adap->dev, "died at 2nd address code\n"); - return -ENXIO; - } - if (flags & I2C_M_RD) { - bit_dbg(3, &i2c_adap->dev, "emitting repeated " - "start condition\n"); - i2c_repstart(adap); - /* okay, now switch into reading mode */ - addr |= 0x01; - ret = try_address(i2c_adap, addr, retries); - if ((ret != 1) && !nak_ok) { - dev_err(&i2c_adap->dev, - "died at repeated address code\n"); - return -EIO; - } - } - } else { /* normal 7bit address */ - addr = msg->addr << 1; - if (flags & I2C_M_RD) - addr |= 1; - if (flags & I2C_M_REV_DIR_ADDR) - addr ^= 1; - ret = try_address(i2c_adap, addr, retries); - if ((ret != 1) && !nak_ok) - return -ENXIO; - } - - return 0; -} - -static int bit_xfer(struct i2c_adapter *i2c_adap, - struct i2c_msg msgs[], int num) -{ - struct i2c_msg *pmsg; - struct i2c_algo_bit_data *adap = i2c_adap->algo_data; - int i, ret; - unsigned short nak_ok; - - if (adap->pre_xfer) { - ret = adap->pre_xfer(i2c_adap); - if (ret < 0) - return ret; - } - - bit_dbg(3, &i2c_adap->dev, "emitting start condition\n"); - i2c_start(adap); - for (i = 0; i < num; i++) { - pmsg = &msgs[i]; - nak_ok = pmsg->flags & I2C_M_IGNORE_NAK; - if (!(pmsg->flags & I2C_M_NOSTART)) { - if (i) { - bit_dbg(3, &i2c_adap->dev, "emitting " - "repeated start condition\n"); - i2c_repstart(adap); - } - ret = bit_doAddress(i2c_adap, pmsg); - if ((ret != 0) && !nak_ok) { - bit_dbg(1, &i2c_adap->dev, "NAK from " - "device addr 0x%02x msg #%d\n", - msgs[i].addr, i); - goto bailout; - } - } - if (pmsg->flags & I2C_M_RD) { - /* read bytes into buffer*/ - ret = readbytes(i2c_adap, pmsg); - if (ret >= 1) - bit_dbg(2, &i2c_adap->dev, "read %d byte%s\n", - ret, ret == 1 ? "" : "s"); - if (ret < pmsg->len) { - if (ret >= 0) - ret = -EIO; - goto bailout; - } - } else { - /* write bytes from buffer */ - ret = sendbytes(i2c_adap, pmsg); - if (ret >= 1) - bit_dbg(2, &i2c_adap->dev, "wrote %d byte%s\n", - ret, ret == 1 ? "" : "s"); - if (ret < pmsg->len) { - if (ret >= 0) - ret = -EIO; - goto bailout; - } - } - } - ret = i; - -bailout: - bit_dbg(3, &i2c_adap->dev, "emitting stop condition\n"); - i2c_stop(adap); - - if (adap->post_xfer) - adap->post_xfer(i2c_adap); - return ret; -} - -static u32 bit_func(struct i2c_adapter *adap) -{ - return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | - I2C_FUNC_SMBUS_READ_BLOCK_DATA | - I2C_FUNC_SMBUS_BLOCK_PROC_CALL | - I2C_FUNC_10BIT_ADDR | I2C_FUNC_PROTOCOL_MANGLING; -} - - -/* -----exported algorithm data: ------------------------------------- */ - -const struct i2c_algorithm i2c_bit_algo = { - .master_xfer = bit_xfer, - .functionality = bit_func, -}; -EXPORT_SYMBOL(i2c_bit_algo); - -/* - * registering functions to load algorithms at runtime - */ -static int __i2c_bit_add_bus(struct i2c_adapter *adap, - int (*add_adapter)(struct i2c_adapter *)) -{ - struct i2c_algo_bit_data *bit_adap = adap->algo_data; - int ret; - - if (bit_test) { - ret = test_bus(adap); - if (bit_test >= 2 && ret < 0) - return -ENODEV; - } - - /* register new adapter to i2c module... */ - adap->algo = &i2c_bit_algo; - adap->retries = 3; - - ret = add_adapter(adap); - if (ret < 0) - return ret; - - /* Complain if SCL can't be read */ - if (bit_adap->getscl == NULL) { - dev_warn(&adap->dev, "Not I2C compliant: can't read SCL\n"); - dev_warn(&adap->dev, "Bus may be unreliable\n"); - } - return 0; -} - -int i2c_bit_add_bus(struct i2c_adapter *adap) -{ - return __i2c_bit_add_bus(adap, i2c_add_adapter); -} -EXPORT_SYMBOL(i2c_bit_add_bus); - -int i2c_bit_add_numbered_bus(struct i2c_adapter *adap) -{ - return __i2c_bit_add_bus(adap, i2c_add_numbered_adapter); -} -EXPORT_SYMBOL(i2c_bit_add_numbered_bus); - -MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); -MODULE_DESCRIPTION("I2C-Bus bit-banging algorithm"); -MODULE_LICENSE("GPL"); |