Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/drivers/i2c/algos/i2c-algo-pca.c b/drivers/i2c/algos/i2c-algo-pca.c
new file mode 100644
index 0000000..c3d912c
--- /dev/null
+++ b/drivers/i2c/algos/i2c-algo-pca.c
@@ -0,0 +1,399 @@
+/*
+ * i2c-algo-pca.c i2c driver algorithms for PCA9564 adapters
+ * Copyright (C) 2004 Arcom Control Systems
+ *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/i2c-algo-pca.h>
+#include "i2c-algo-pca.h"
+
+#define DRIVER "i2c-algo-pca"
+
+#define DEB1(fmt, args...) do { if (i2c_debug>=1) printk(fmt, ## args); } while(0)
+#define DEB2(fmt, args...) do { if (i2c_debug>=2) printk(fmt, ## args); } while(0)
+#define DEB3(fmt, args...) do { if (i2c_debug>=3) printk(fmt, ## args); } while(0)
+
+static int i2c_debug=0;
+
+#define pca_outw(adap, reg, val) adap->write_byte(adap, reg, val)
+#define pca_inw(adap, reg) adap->read_byte(adap, reg)
+
+#define pca_status(adap) pca_inw(adap, I2C_PCA_STA)
+#define pca_clock(adap) adap->get_clock(adap)
+#define pca_own(adap) adap->get_own(adap)
+#define pca_set_con(adap, val) pca_outw(adap, I2C_PCA_CON, val)
+#define pca_get_con(adap) pca_inw(adap, I2C_PCA_CON)
+#define pca_wait(adap) adap->wait_for_interrupt(adap)
+
+/*
+ * Generate a start condition on the i2c bus.
+ *
+ * returns after the start condition has occured
+ */
+static void pca_start(struct i2c_algo_pca_data *adap)
+{
+ int sta = pca_get_con(adap);
+ DEB2("=== START\n");
+ sta |= I2C_PCA_CON_STA;
+ sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_SI);
+ pca_set_con(adap, sta);
+ pca_wait(adap);
+}
+
+/*
+ * Generate a repeated start condition on the i2c bus
+ *
+ * return after the repeated start condition has occured
+ */
+static void pca_repeated_start(struct i2c_algo_pca_data *adap)
+{
+ int sta = pca_get_con(adap);
+ DEB2("=== REPEATED START\n");
+ sta |= I2C_PCA_CON_STA;
+ sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_SI);
+ pca_set_con(adap, sta);
+ pca_wait(adap);
+}
+
+/*
+ * Generate a stop condition on the i2c bus
+ *
+ * returns after the stop condition has been generated
+ *
+ * STOPs do not generate an interrupt or set the SI flag, since the
+ * part returns the the idle state (0xf8). Hence we don't need to
+ * pca_wait here.
+ */
+static void pca_stop(struct i2c_algo_pca_data *adap)
+{
+ int sta = pca_get_con(adap);
+ DEB2("=== STOP\n");
+ sta |= I2C_PCA_CON_STO;
+ sta &= ~(I2C_PCA_CON_STA|I2C_PCA_CON_SI);
+ pca_set_con(adap, sta);
+}
+
+/*
+ * Send the slave address and R/W bit
+ *
+ * returns after the address has been sent
+ */
+static void pca_address(struct i2c_algo_pca_data *adap,
+ struct i2c_msg *msg)
+{
+ int sta = pca_get_con(adap);
+ int addr;
+
+ addr = ( (0x7f & msg->addr) << 1 );
+ if (msg->flags & I2C_M_RD )
+ addr |= 1;
+ DEB2("=== SLAVE ADDRESS %#04x+%c=%#04x\n",
+ msg->addr, msg->flags & I2C_M_RD ? 'R' : 'W', addr);
+
+ pca_outw(adap, I2C_PCA_DAT, addr);
+
+ sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_STA|I2C_PCA_CON_SI);
+ pca_set_con(adap, sta);
+
+ pca_wait(adap);
+}
+
+/*
+ * Transmit a byte.
+ *
+ * Returns after the byte has been transmitted
+ */
+static void pca_tx_byte(struct i2c_algo_pca_data *adap,
+ __u8 b)
+{
+ int sta = pca_get_con(adap);
+ DEB2("=== WRITE %#04x\n", b);
+ pca_outw(adap, I2C_PCA_DAT, b);
+
+ sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_STA|I2C_PCA_CON_SI);
+ pca_set_con(adap, sta);
+
+ pca_wait(adap);
+}
+
+/*
+ * Receive a byte
+ *
+ * returns immediately.
+ */
+static void pca_rx_byte(struct i2c_algo_pca_data *adap,
+ __u8 *b, int ack)
+{
+ *b = pca_inw(adap, I2C_PCA_DAT);
+ DEB2("=== READ %#04x %s\n", *b, ack ? "ACK" : "NACK");
+}
+
+/*
+ * Setup ACK or NACK for next received byte and wait for it to arrive.
+ *
+ * Returns after next byte has arrived.
+ */
+static void pca_rx_ack(struct i2c_algo_pca_data *adap,
+ int ack)
+{
+ int sta = pca_get_con(adap);
+
+ sta &= ~(I2C_PCA_CON_STO|I2C_PCA_CON_STA|I2C_PCA_CON_SI|I2C_PCA_CON_AA);
+
+ if ( ack )
+ sta |= I2C_PCA_CON_AA;
+
+ pca_set_con(adap, sta);
+ pca_wait(adap);
+}
+
+/*
+ * Reset the i2c bus / SIO
+ */
+static void pca_reset(struct i2c_algo_pca_data *adap)
+{
+ /* apparently only an external reset will do it. not a lot can be done */
+ printk(KERN_ERR DRIVER ": Haven't figured out how to do a reset yet\n");
+}
+
+static int pca_xfer(struct i2c_adapter *i2c_adap,
+ struct i2c_msg *msgs,
+ int num)
+{
+ struct i2c_algo_pca_data *adap = i2c_adap->algo_data;
+ struct i2c_msg *msg = NULL;
+ int curmsg;
+ int numbytes = 0;
+ int state;
+ int ret;
+
+ state = pca_status(adap);
+ if ( state != 0xF8 ) {
+ dev_dbg(&i2c_adap->dev, "bus is not idle. status is %#04x\n", state );
+ /* FIXME: what to do. Force stop ? */
+ return -EREMOTEIO;
+ }
+
+ DEB1("{{{ XFER %d messages\n", num);
+
+ if (i2c_debug>=2) {
+ for (curmsg = 0; curmsg < num; curmsg++) {
+ int addr, i;
+ msg = &msgs[curmsg];
+
+ addr = (0x7f & msg->addr) ;
+
+ if (msg->flags & I2C_M_RD )
+ printk(KERN_INFO " [%02d] RD %d bytes from %#02x [%#02x, ...]\n",
+ curmsg, msg->len, addr, (addr<<1) | 1);
+ else {
+ printk(KERN_INFO " [%02d] WR %d bytes to %#02x [%#02x%s",
+ curmsg, msg->len, addr, addr<<1,
+ msg->len == 0 ? "" : ", ");
+ for(i=0; i < msg->len; i++)
+ printk("%#04x%s", msg->buf[i], i == msg->len - 1 ? "" : ", ");
+ printk("]\n");
+ }
+ }
+ }
+
+ curmsg = 0;
+ ret = -EREMOTEIO;
+ while (curmsg < num) {
+ state = pca_status(adap);
+
+ DEB3("STATE is 0x%02x\n", state);
+ msg = &msgs[curmsg];
+
+ switch (state) {
+ case 0xf8: /* On reset or stop the bus is idle */
+ pca_start(adap);
+ break;
+
+ case 0x08: /* A START condition has been transmitted */
+ case 0x10: /* A repeated start condition has been transmitted */
+ pca_address(adap, msg);
+ break;
+
+ case 0x18: /* SLA+W has been transmitted; ACK has been received */
+ case 0x28: /* Data byte in I2CDAT has been transmitted; ACK has been received */
+ if (numbytes < msg->len) {
+ pca_tx_byte(adap, msg->buf[numbytes]);
+ numbytes++;
+ break;
+ }
+ curmsg++; numbytes = 0;
+ if (curmsg == num)
+ pca_stop(adap);
+ else
+ pca_repeated_start(adap);
+ break;
+
+ case 0x20: /* SLA+W has been transmitted; NOT ACK has been received */
+ DEB2("NOT ACK received after SLA+W\n");
+ pca_stop(adap);
+ goto out;
+
+ case 0x40: /* SLA+R has been transmitted; ACK has been received */
+ pca_rx_ack(adap, msg->len > 1);
+ break;
+
+ case 0x50: /* Data bytes has been received; ACK has been returned */
+ if (numbytes < msg->len) {
+ pca_rx_byte(adap, &msg->buf[numbytes], 1);
+ numbytes++;
+ pca_rx_ack(adap, numbytes < msg->len - 1);
+ break;
+ }
+ curmsg++; numbytes = 0;
+ if (curmsg == num)
+ pca_stop(adap);
+ else
+ pca_repeated_start(adap);
+ break;
+
+ case 0x48: /* SLA+R has been transmitted; NOT ACK has been received */
+ DEB2("NOT ACK received after SLA+R\n");
+ pca_stop(adap);
+ goto out;
+
+ case 0x30: /* Data byte in I2CDAT has been transmitted; NOT ACK has been received */
+ DEB2("NOT ACK received after data byte\n");
+ goto out;
+
+ case 0x38: /* Arbitration lost during SLA+W, SLA+R or data bytes */
+ DEB2("Arbitration lost\n");
+ goto out;
+
+ case 0x58: /* Data byte has been received; NOT ACK has been returned */
+ if ( numbytes == msg->len - 1 ) {
+ pca_rx_byte(adap, &msg->buf[numbytes], 0);
+ curmsg++; numbytes = 0;
+ if (curmsg == num)
+ pca_stop(adap);
+ else
+ pca_repeated_start(adap);
+ } else {
+ DEB2("NOT ACK sent after data byte received. "
+ "Not final byte. numbytes %d. len %d\n",
+ numbytes, msg->len);
+ pca_stop(adap);
+ goto out;
+ }
+ break;
+ case 0x70: /* Bus error - SDA stuck low */
+ DEB2("BUS ERROR - SDA Stuck low\n");
+ pca_reset(adap);
+ goto out;
+ case 0x90: /* Bus error - SCL stuck low */
+ DEB2("BUS ERROR - SCL Stuck low\n");
+ pca_reset(adap);
+ goto out;
+ case 0x00: /* Bus error during master or slave mode due to illegal START or STOP condition */
+ DEB2("BUS ERROR - Illegal START or STOP\n");
+ pca_reset(adap);
+ goto out;
+ default:
+ printk(KERN_ERR DRIVER ": unhandled SIO state 0x%02x\n", state);
+ break;
+ }
+
+ }
+
+ ret = curmsg;
+ out:
+ DEB1(KERN_CRIT "}}} transfered %d/%d messages. "
+ "status is %#04x. control is %#04x\n",
+ curmsg, num, pca_status(adap),
+ pca_get_con(adap));
+ return ret;
+}
+
+static u32 pca_func(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static int pca_init(struct i2c_algo_pca_data *adap)
+{
+ static int freqs[] = {330,288,217,146,88,59,44,36};
+ int own, clock;
+
+ own = pca_own(adap);
+ clock = pca_clock(adap);
+ DEB1(KERN_INFO DRIVER ": own address is %#04x\n", own);
+ DEB1(KERN_INFO DRIVER ": clock freqeuncy is %dkHz\n", freqs[clock]);
+
+ pca_outw(adap, I2C_PCA_ADR, own << 1);
+
+ pca_set_con(adap, I2C_PCA_CON_ENSIO | clock);
+ udelay(500); /* 500 µs for oscilator to stabilise */
+
+ return 0;
+}
+
+static struct i2c_algorithm pca_algo = {
+ .name = "PCA9564 algorithm",
+ .id = I2C_ALGO_PCA,
+ .master_xfer = pca_xfer,
+ .functionality = pca_func,
+};
+
+/*
+ * registering functions to load algorithms at runtime
+ */
+int i2c_pca_add_bus(struct i2c_adapter *adap)
+{
+ struct i2c_algo_pca_data *pca_adap = adap->algo_data;
+ int rval;
+
+ /* register new adapter to i2c module... */
+
+ adap->id |= pca_algo.id;
+ adap->algo = &pca_algo;
+
+ adap->timeout = 100; /* default values, should */
+ adap->retries = 3; /* be replaced by defines */
+
+ rval = pca_init(pca_adap);
+
+ if (!rval)
+ i2c_add_adapter(adap);
+
+ return rval;
+}
+
+int i2c_pca_del_bus(struct i2c_adapter *adap)
+{
+ return i2c_del_adapter(adap);
+}
+
+EXPORT_SYMBOL(i2c_pca_add_bus);
+EXPORT_SYMBOL(i2c_pca_del_bus);
+
+MODULE_AUTHOR("Ian Campbell <icampbell@arcom.com>");
+MODULE_DESCRIPTION("I2C-Bus PCA9564 algorithm");
+MODULE_LICENSE("GPL");
+
+module_param(i2c_debug, int, 0);