| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Linus Torvalds (pre-git) | 1027 | 60.88% | 3 | 11.54% |
| Linus Torvalds | 321 | 19.03% | 2 | 7.69% |
| Eric Brower | 136 | 8.06% | 2 | 7.69% |
| David S. Miller | 62 | 3.68% | 3 | 11.54% |
| Greg Kroah-Hartman | 41 | 2.43% | 3 | 11.54% |
| Roel Kluin | 35 | 2.07% | 2 | 7.69% |
| Albert Cranford | 25 | 1.48% | 1 | 3.85% |
| Christoph Hellwig | 13 | 0.77% | 1 | 3.85% |
| Mark M. Hoffman | 9 | 0.53% | 1 | 3.85% |
| Peter Rosin | 7 | 0.41% | 1 | 3.85% |
| Steven Cole | 3 | 0.18% | 1 | 3.85% |
| Thomas Gleixner | 2 | 0.12% | 1 | 3.85% |
| Ian Campbell | 2 | 0.12% | 1 | 3.85% |
| Uwe Kleine-König | 1 | 0.06% | 1 | 3.85% |
| Frank Seidel | 1 | 0.06% | 1 | 3.85% |
| Jean Delvare | 1 | 0.06% | 1 | 3.85% |
| Mickey Stein | 1 | 0.06% | 1 | 3.85% |
| Total | 1687 | 26 |
// SPDX-License-Identifier: GPL-2.0-or-later /* * i2c-algo-pcf.c i2c driver algorithms for PCF8584 adapters * * Copyright (C) 1995-1997 Simon G. Vogl * 1998-2000 Hans Berglund * * With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and * Frodo Looijaard <frodol@dds.nl>, and also from Martin Bailey * <mbailey@littlefeet-inc.com> * * Partially rewriten by Oleg I. Vdovikin <vdovikin@jscc.ru> to handle multiple * messages, proper stop/repstart signaling during receive, added detect code */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/delay.h> #include <linux/errno.h> #include <linux/i2c.h> #include <linux/i2c-algo-pcf.h> #include "i2c-algo-pcf.h" #define DEB2(x) if (i2c_debug >= 2) x #define DEB3(x) if (i2c_debug >= 3) x /* print several statistical values */ #define DEBPROTO(x) if (i2c_debug >= 9) x; /* debug the protocol by showing transferred bits */ #define DEF_TIMEOUT 16 /* * module parameters: */ static int i2c_debug; /* setting states on the bus with the right timing: */ #define set_pcf(adap, ctl, val) adap->setpcf(adap->data, ctl, val) #define get_pcf(adap, ctl) adap->getpcf(adap->data, ctl) #define get_own(adap) adap->getown(adap->data) #define get_clock(adap) adap->getclock(adap->data) #define i2c_outb(adap, val) adap->setpcf(adap->data, 0, val) #define i2c_inb(adap) adap->getpcf(adap->data, 0) /* other auxiliary functions */ static void i2c_start(struct i2c_algo_pcf_data *adap) { DEBPROTO(printk(KERN_DEBUG "S ")); set_pcf(adap, 1, I2C_PCF_START); } static void i2c_repstart(struct i2c_algo_pcf_data *adap) { DEBPROTO(printk(" Sr ")); set_pcf(adap, 1, I2C_PCF_REPSTART); } static void i2c_stop(struct i2c_algo_pcf_data *adap) { DEBPROTO(printk("P\n")); set_pcf(adap, 1, I2C_PCF_STOP); } static void handle_lab(struct i2c_algo_pcf_data *adap, const int *status) { DEB2(printk(KERN_INFO "i2c-algo-pcf.o: lost arbitration (CSR 0x%02x)\n", *status)); /* * Cleanup from LAB -- reset and enable ESO. * This resets the PCF8584; since we've lost the bus, no * further attempts should be made by callers to clean up * (no i2c_stop() etc.) */ set_pcf(adap, 1, I2C_PCF_PIN); set_pcf(adap, 1, I2C_PCF_ESO); /* * We pause for a time period sufficient for any running * I2C transaction to complete -- the arbitration logic won't * work properly until the next START is seen. * It is assumed the bus driver or client has set a proper value. * * REVISIT: should probably use msleep instead of mdelay if we * know we can sleep. */ if (adap->lab_mdelay) mdelay(adap->lab_mdelay); DEB2(printk(KERN_INFO "i2c-algo-pcf.o: reset LAB condition (CSR 0x%02x)\n", get_pcf(adap, 1))); } static int wait_for_bb(struct i2c_algo_pcf_data *adap) { int timeout = DEF_TIMEOUT; int status; status = get_pcf(adap, 1); while (!(status & I2C_PCF_BB) && --timeout) { udelay(100); /* wait for 100 us */ status = get_pcf(adap, 1); } if (timeout == 0) { printk(KERN_ERR "Timeout waiting for Bus Busy\n"); return -ETIMEDOUT; } return 0; } static int wait_for_pin(struct i2c_algo_pcf_data *adap, int *status) { int timeout = DEF_TIMEOUT; *status = get_pcf(adap, 1); while ((*status & I2C_PCF_PIN) && --timeout) { adap->waitforpin(adap->data); *status = get_pcf(adap, 1); } if (*status & I2C_PCF_LAB) { handle_lab(adap, status); return -EINTR; } if (timeout == 0) return -ETIMEDOUT; return 0; } /* * This should perform the 'PCF8584 initialization sequence' as described * in the Philips IC12 data book (1995, Aug 29). * There should be a 30 clock cycle wait after reset, I assume this * has been fulfilled. * There should be a delay at the end equal to the longest I2C message * to synchronize the BB-bit (in multimaster systems). How long is * this? I assume 1 second is always long enough. * * vdovikin: added detect code for PCF8584 */ static int pcf_init_8584 (struct i2c_algo_pcf_data *adap) { unsigned char temp; DEB3(printk(KERN_DEBUG "i2c-algo-pcf.o: PCF state 0x%02x\n", get_pcf(adap, 1))); /* S1=0x80: S0 selected, serial interface off */ set_pcf(adap, 1, I2C_PCF_PIN); /* * check to see S1 now used as R/W ctrl - * PCF8584 does that when ESO is zero */ if (((temp = get_pcf(adap, 1)) & 0x7f) != (0)) { DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S0 (0x%02x).\n", temp)); return -ENXIO; /* definitely not PCF8584 */ } /* load own address in S0, effective address is (own << 1) */ i2c_outb(adap, get_own(adap)); /* check it's really written */ if ((temp = i2c_inb(adap)) != get_own(adap)) { DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't set S0 (0x%02x).\n", temp)); return -ENXIO; } /* S1=0xA0, next byte in S2 */ set_pcf(adap, 1, I2C_PCF_PIN | I2C_PCF_ES1); /* check to see S2 now selected */ if (((temp = get_pcf(adap, 1)) & 0x7f) != I2C_PCF_ES1) { DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S2 (0x%02x).\n", temp)); return -ENXIO; } /* load clock register S2 */ i2c_outb(adap, get_clock(adap)); /* check it's really written, the only 5 lowest bits does matter */ if (((temp = i2c_inb(adap)) & 0x1f) != get_clock(adap)) { DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't set S2 (0x%02x).\n", temp)); return -ENXIO; } /* Enable serial interface, idle, S0 selected */ set_pcf(adap, 1, I2C_PCF_IDLE); /* check to see PCF is really idled and we can access status register */ if ((temp = get_pcf(adap, 1)) != (I2C_PCF_PIN | I2C_PCF_BB)) { DEB2(printk(KERN_ERR "i2c-algo-pcf.o: PCF detection failed -- can't select S1` (0x%02x).\n", temp)); return -ENXIO; } printk(KERN_DEBUG "i2c-algo-pcf.o: detected and initialized PCF8584.\n"); return 0; } static int pcf_sendbytes(struct i2c_adapter *i2c_adap, const char *buf, int count, int last) { struct i2c_algo_pcf_data *adap = i2c_adap->algo_data; int wrcount, status, timeout; for (wrcount=0; wrcount<count; ++wrcount) { DEB2(dev_dbg(&i2c_adap->dev, "i2c_write: writing %2.2X\n", buf[wrcount] & 0xff)); i2c_outb(adap, buf[wrcount]); timeout = wait_for_pin(adap, &status); if (timeout) { if (timeout == -EINTR) return -EINTR; /* arbitration lost */ i2c_stop(adap); dev_err(&i2c_adap->dev, "i2c_write: error - timeout.\n"); return -EREMOTEIO; /* got a better one ?? */ } if (status & I2C_PCF_LRB) { i2c_stop(adap); dev_err(&i2c_adap->dev, "i2c_write: error - no ack.\n"); return -EREMOTEIO; /* got a better one ?? */ } } if (last) i2c_stop(adap); else i2c_repstart(adap); return wrcount; } static int pcf_readbytes(struct i2c_adapter *i2c_adap, char *buf, int count, int last) { int i, status; struct i2c_algo_pcf_data *adap = i2c_adap->algo_data; int wfp; /* increment number of bytes to read by one -- read dummy byte */ for (i = 0; i <= count; i++) { if ((wfp = wait_for_pin(adap, &status))) { if (wfp == -EINTR) return -EINTR; /* arbitration lost */ i2c_stop(adap); dev_err(&i2c_adap->dev, "pcf_readbytes timed out.\n"); return -1; } if ((status & I2C_PCF_LRB) && (i != count)) { i2c_stop(adap); dev_err(&i2c_adap->dev, "i2c_read: i2c_inb, No ack.\n"); return -1; } if (i == count - 1) { set_pcf(adap, 1, I2C_PCF_ESO); } else if (i == count) { if (last) i2c_stop(adap); else i2c_repstart(adap); } if (i) buf[i - 1] = i2c_inb(adap); else i2c_inb(adap); /* dummy read */ } return i - 1; } static int pcf_doAddress(struct i2c_algo_pcf_data *adap, struct i2c_msg *msg) { unsigned char addr = i2c_8bit_addr_from_msg(msg); if (msg->flags & I2C_M_REV_DIR_ADDR) addr ^= 1; i2c_outb(adap, addr); return 0; } static int pcf_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num) { struct i2c_algo_pcf_data *adap = i2c_adap->algo_data; struct i2c_msg *pmsg; int i; int ret=0, timeout, status; if (adap->xfer_begin) adap->xfer_begin(adap->data); /* Check for bus busy */ timeout = wait_for_bb(adap); if (timeout) { DEB2(printk(KERN_ERR "i2c-algo-pcf.o: " "Timeout waiting for BB in pcf_xfer\n");) i = -EIO; goto out; } for (i = 0;ret >= 0 && i < num; i++) { pmsg = &msgs[i]; DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: Doing %s %d bytes to 0x%02x - %d of %d messages\n", pmsg->flags & I2C_M_RD ? "read" : "write", pmsg->len, pmsg->addr, i + 1, num);) ret = pcf_doAddress(adap, pmsg); /* Send START */ if (i == 0) i2c_start(adap); /* Wait for PIN (pending interrupt NOT) */ timeout = wait_for_pin(adap, &status); if (timeout) { if (timeout == -EINTR) { /* arbitration lost */ i = -EINTR; goto out; } i2c_stop(adap); DEB2(printk(KERN_ERR "i2c-algo-pcf.o: Timeout waiting " "for PIN(1) in pcf_xfer\n");) i = -EREMOTEIO; goto out; } /* Check LRB (last rcvd bit - slave ack) */ if (status & I2C_PCF_LRB) { i2c_stop(adap); DEB2(printk(KERN_ERR "i2c-algo-pcf.o: No LRB(1) in pcf_xfer\n");) i = -EREMOTEIO; goto out; } DEB3(printk(KERN_DEBUG "i2c-algo-pcf.o: Msg %d, addr=0x%x, flags=0x%x, len=%d\n", i, msgs[i].addr, msgs[i].flags, msgs[i].len);) if (pmsg->flags & I2C_M_RD) { ret = pcf_readbytes(i2c_adap, pmsg->buf, pmsg->len, (i + 1 == num)); if (ret != pmsg->len) { DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: " "only read %d bytes.\n",ret)); } else { DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: read %d bytes.\n",ret)); } } else { ret = pcf_sendbytes(i2c_adap, pmsg->buf, pmsg->len, (i + 1 == num)); if (ret != pmsg->len) { DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: fail: " "only wrote %d bytes.\n",ret)); } else { DEB2(printk(KERN_DEBUG "i2c-algo-pcf.o: wrote %d bytes.\n",ret)); } } } out: if (adap->xfer_end) adap->xfer_end(adap->data); return i; } static u32 pcf_func(struct i2c_adapter *adap) { return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_PROTOCOL_MANGLING; } /* exported algorithm data: */ static const struct i2c_algorithm pcf_algo = { .master_xfer = pcf_xfer, .functionality = pcf_func, }; /* * registering functions to load algorithms at runtime */ int i2c_pcf_add_bus(struct i2c_adapter *adap) { struct i2c_algo_pcf_data *pcf_adap = adap->algo_data; int rval; DEB2(dev_dbg(&adap->dev, "hw routines registered.\n")); /* register new adapter to i2c module... */ adap->algo = &pcf_algo; if ((rval = pcf_init_8584(pcf_adap))) return rval; rval = i2c_add_adapter(adap); return rval; } EXPORT_SYMBOL(i2c_pcf_add_bus); MODULE_AUTHOR("Hans Berglund <hb@spacetec.no>"); MODULE_DESCRIPTION("I2C-Bus PCF8584 algorithm"); MODULE_LICENSE("GPL"); module_param(i2c_debug, int, S_IRUGO | S_IWUSR); MODULE_PARM_DESC(i2c_debug, "debug level - 0 off; 1 normal; 2,3 more verbose; 9 pcf-protocol");
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