Return-path: Received: from mail-ey0-f174.google.com ([209.85.215.174]:33578 "EHLO mail-ey0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753973Ab2GBOWe (ORCPT ); Mon, 2 Jul 2012 10:22:34 -0400 Received: by mail-ey0-f174.google.com with SMTP id k11so2110016eaa.19 for ; Mon, 02 Jul 2012 07:22:33 -0700 (PDT) From: =?UTF-8?q?Ozan=20=C3=87a=C4=9Flayan?= To: mcgrof@kernel.org Cc: linux-wireless@vger.kernel.org, =?UTF-8?q?Ozan=20=C3=87a=C4=9Flayan?= Subject: [PATCH 4/5] compat: Backport i2c_bit_algo structure Date: Mon, 2 Jul 2012 17:22:13 +0300 Message-Id: <1341238934-30855-4-git-send-email-ozancag@gmail.com> (sfid-20120702_162244_619762_793FBA2E) In-Reply-To: <1341238934-30855-1-git-send-email-ozancag@gmail.com> References: <1341238934-30855-1-git-send-email-ozancag@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: This backports all the necessary helpers for being able to export i2c-bit_algo structure. This is currently only used by drivers/gpu/drm/i915/intel_i2c.c. This is only enabled for kernels >= 2.6.34. Trying kernel 3.4.0-030400-generic [OK] Trying kernel 3.3.7-030307-generic [OK] Trying kernel 3.2.2-030202-generic [OK] Trying kernel 3.1.10-030110-generic [OK] Trying kernel 3.0.18-030018-generic [OK] Trying kernel 2.6.39-02063904-generic [OK] Trying kernel 2.6.38-02063808-generic [OK] Trying kernel 2.6.37-02063706-generic [OK] Trying kernel 2.6.36-02063604-generic [OK] Trying kernel 2.6.35-02063512-generic [OK] Trying kernel 2.6.34-02063410-generic [OK] Trying kernel 2.6.33-02063305-generic [OK] Trying kernel 2.6.32-02063255-generic [OK] Trying kernel 2.6.31-02063113-generic [OK] Trying kernel 2.6.30-02063010-generic [OK] Trying kernel 2.6.29-02062906-generic [OK] Trying kernel 2.6.28-02062810-generic [OK] Trying kernel 2.6.27-020627-generic [OK] Trying kernel 2.6.26-020626-generic [OK] Trying kernel 2.6.25-020625-generic [OK] Trying kernel 2.6.24-020624-generic [OK] Signed-off-by: Ozan Çağlayan --- compat/compat-3.4.c | 442 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/compat-3.4.h | 4 + 2 files changed, 446 insertions(+) diff --git a/compat/compat-3.4.c b/compat/compat-3.4.c index 4721fa2..4ff439b 100644 --- a/compat/compat-3.4.c +++ b/compat/compat-3.4.c @@ -11,6 +11,448 @@ #include #include +#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,34)) +#include +#include +#include + +#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) + +#define bit_dbg(level, dev, format, args...) \ + do {} while (0) + +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); +} + +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; +} + +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); +} + +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; +} + +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 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 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; +} + + +static u32 bit_func(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_NOSTART | I2C_FUNC_SMBUS_EMUL | + I2C_FUNC_SMBUS_READ_BLOCK_DATA | + I2C_FUNC_SMBUS_BLOCK_PROC_CALL | + I2C_FUNC_10BIT_ADDR | I2C_FUNC_PROTOCOL_MANGLING; +} + +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; +} + + +const struct i2c_algorithm i2c_bit_algo = { + .master_xfer = bit_xfer, + .functionality = bit_func, +}; +EXPORT_SYMBOL(i2c_bit_algo); +#endif + int simple_open(struct inode *inode, struct file *file) { if (inode->i_private) diff --git a/include/linux/compat-3.4.h b/include/linux/compat-3.4.h index f343795..e603f4c 100644 --- a/include/linux/compat-3.4.h +++ b/include/linux/compat-3.4.h @@ -8,6 +8,10 @@ #include #include +#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,34)) +extern const struct i2c_algorithm i2c_bit_algo; +#endif + extern int simple_open(struct inode *inode, struct file *file); #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,28)) -- 1.7.10.4