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Diffstat (limited to 'drivers/i2c/busses/i2c-s3c2410.c')
-rw-r--r--drivers/i2c/busses/i2c-s3c2410.c938
1 files changed, 938 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
new file mode 100644
index 000000000000..fcfa51c1436b
--- /dev/null
+++ b/drivers/i2c/busses/i2c-s3c2410.c
@@ -0,0 +1,938 @@
+/* linux/drivers/i2c/busses/i2c-s3c2410.c
+ *
+ * Copyright (C) 2004,2005 Simtec Electronics
+ * Ben Dooks <ben@simtec.co.uk>
+ *
+ * S3C2410 I2C Controller
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+*/
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include <linux/i2c.h>
+#include <linux/i2c-id.h>
+#include <linux/init.h>
+#include <linux/time.h>
+#include <linux/interrupt.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/device.h>
+
+#include <asm/hardware.h>
+#include <asm/irq.h>
+#include <asm/io.h>
+
+#include <asm/hardware/clock.h>
+#include <asm/arch/regs-gpio.h>
+#include <asm/arch/regs-iic.h>
+#include <asm/arch/iic.h>
+
+/* i2c controller state */
+
+enum s3c24xx_i2c_state {
+ STATE_IDLE,
+ STATE_START,
+ STATE_READ,
+ STATE_WRITE,
+ STATE_STOP
+};
+
+struct s3c24xx_i2c {
+ spinlock_t lock;
+ wait_queue_head_t wait;
+
+ struct i2c_msg *msg;
+ unsigned int msg_num;
+ unsigned int msg_idx;
+ unsigned int msg_ptr;
+
+ enum s3c24xx_i2c_state state;
+
+ void __iomem *regs;
+ struct clk *clk;
+ struct device *dev;
+ struct resource *irq;
+ struct resource *ioarea;
+ struct i2c_adapter adap;
+};
+
+/* default platform data to use if not supplied in the platform_device
+*/
+
+static struct s3c2410_platform_i2c s3c24xx_i2c_default_platform = {
+ .flags = 0,
+ .slave_addr = 0x10,
+ .bus_freq = 100*1000,
+ .max_freq = 400*1000,
+ .sda_delay = S3C2410_IICLC_SDA_DELAY5 | S3C2410_IICLC_FILTER_ON,
+};
+
+/* s3c24xx_i2c_is2440()
+ *
+ * return true is this is an s3c2440
+*/
+
+static inline int s3c24xx_i2c_is2440(struct s3c24xx_i2c *i2c)
+{
+ struct platform_device *pdev = to_platform_device(i2c->dev);
+
+ return !strcmp(pdev->name, "s3c2440-i2c");
+}
+
+
+/* s3c24xx_i2c_get_platformdata
+ *
+ * get the platform data associated with the given device, or return
+ * the default if there is none
+*/
+
+static inline struct s3c2410_platform_i2c *s3c24xx_i2c_get_platformdata(struct device *dev)
+{
+ if (dev->platform_data != NULL)
+ return (struct s3c2410_platform_i2c *)dev->platform_data;
+
+ return &s3c24xx_i2c_default_platform;
+}
+
+/* s3c24xx_i2c_master_complete
+ *
+ * complete the message and wake up the caller, using the given return code,
+ * or zero to mean ok.
+*/
+
+static inline void s3c24xx_i2c_master_complete(struct s3c24xx_i2c *i2c, int ret)
+{
+ dev_dbg(i2c->dev, "master_complete %d\n", ret);
+
+ i2c->msg_ptr = 0;
+ i2c->msg = NULL;
+ i2c->msg_idx ++;
+ i2c->msg_num = 0;
+ if (ret)
+ i2c->msg_idx = ret;
+
+ wake_up(&i2c->wait);
+}
+
+static inline void s3c24xx_i2c_disable_ack(struct s3c24xx_i2c *i2c)
+{
+ unsigned long tmp;
+
+ tmp = readl(i2c->regs + S3C2410_IICCON);
+ writel(tmp & ~S3C2410_IICCON_ACKEN, i2c->regs + S3C2410_IICCON);
+
+}
+
+static inline void s3c24xx_i2c_enable_ack(struct s3c24xx_i2c *i2c)
+{
+ unsigned long tmp;
+
+ tmp = readl(i2c->regs + S3C2410_IICCON);
+ writel(tmp | S3C2410_IICCON_ACKEN, i2c->regs + S3C2410_IICCON);
+
+}
+
+/* irq enable/disable functions */
+
+static inline void s3c24xx_i2c_disable_irq(struct s3c24xx_i2c *i2c)
+{
+ unsigned long tmp;
+
+ tmp = readl(i2c->regs + S3C2410_IICCON);
+ writel(tmp & ~S3C2410_IICCON_IRQEN, i2c->regs + S3C2410_IICCON);
+}
+
+static inline void s3c24xx_i2c_enable_irq(struct s3c24xx_i2c *i2c)
+{
+ unsigned long tmp;
+
+ tmp = readl(i2c->regs + S3C2410_IICCON);
+ writel(tmp | S3C2410_IICCON_IRQEN, i2c->regs + S3C2410_IICCON);
+}
+
+
+/* s3c24xx_i2c_message_start
+ *
+ * put the start of a message onto the bus
+*/
+
+static void s3c24xx_i2c_message_start(struct s3c24xx_i2c *i2c,
+ struct i2c_msg *msg)
+{
+ unsigned int addr = (msg->addr & 0x7f) << 1;
+ unsigned long stat;
+ unsigned long iiccon;
+
+ stat = 0;
+ stat |= S3C2410_IICSTAT_TXRXEN;
+
+ if (msg->flags & I2C_M_RD) {
+ stat |= S3C2410_IICSTAT_MASTER_RX;
+ addr |= 1;
+ } else
+ stat |= S3C2410_IICSTAT_MASTER_TX;
+
+ if (msg->flags & I2C_M_REV_DIR_ADDR)
+ addr ^= 1;
+
+ // todo - check for wether ack wanted or not
+ s3c24xx_i2c_enable_ack(i2c);
+
+ iiccon = readl(i2c->regs + S3C2410_IICCON);
+ writel(stat, i2c->regs + S3C2410_IICSTAT);
+
+ dev_dbg(i2c->dev, "START: %08lx to IICSTAT, %02x to DS\n", stat, addr);
+ writeb(addr, i2c->regs + S3C2410_IICDS);
+
+ // delay a bit and reset iiccon before setting start (per samsung)
+ udelay(1);
+ dev_dbg(i2c->dev, "iiccon, %08lx\n", iiccon);
+ writel(iiccon, i2c->regs + S3C2410_IICCON);
+
+ stat |= S3C2410_IICSTAT_START;
+ writel(stat, i2c->regs + S3C2410_IICSTAT);
+}
+
+static inline void s3c24xx_i2c_stop(struct s3c24xx_i2c *i2c, int ret)
+{
+ unsigned long iicstat = readl(i2c->regs + S3C2410_IICSTAT);
+
+ dev_dbg(i2c->dev, "STOP\n");
+
+ /* stop the transfer */
+ iicstat &= ~ S3C2410_IICSTAT_START;
+ writel(iicstat, i2c->regs + S3C2410_IICSTAT);
+
+ i2c->state = STATE_STOP;
+
+ s3c24xx_i2c_master_complete(i2c, ret);
+ s3c24xx_i2c_disable_irq(i2c);
+}
+
+/* helper functions to determine the current state in the set of
+ * messages we are sending */
+
+/* is_lastmsg()
+ *
+ * returns TRUE if the current message is the last in the set
+*/
+
+static inline int is_lastmsg(struct s3c24xx_i2c *i2c)
+{
+ return i2c->msg_idx >= (i2c->msg_num - 1);
+}
+
+/* is_msglast
+ *
+ * returns TRUE if we this is the last byte in the current message
+*/
+
+static inline int is_msglast(struct s3c24xx_i2c *i2c)
+{
+ return i2c->msg_ptr == i2c->msg->len-1;
+}
+
+/* is_msgend
+ *
+ * returns TRUE if we reached the end of the current message
+*/
+
+static inline int is_msgend(struct s3c24xx_i2c *i2c)
+{
+ return i2c->msg_ptr >= i2c->msg->len;
+}
+
+/* i2s_s3c_irq_nextbyte
+ *
+ * process an interrupt and work out what to do
+ */
+
+static int i2s_s3c_irq_nextbyte(struct s3c24xx_i2c *i2c, unsigned long iicstat)
+{
+ unsigned long tmp;
+ unsigned char byte;
+ int ret = 0;
+
+ switch (i2c->state) {
+
+ case STATE_IDLE:
+ dev_err(i2c->dev, "%s: called in STATE_IDLE\n", __FUNCTION__);
+ goto out;
+ break;
+
+ case STATE_STOP:
+ dev_err(i2c->dev, "%s: called in STATE_STOP\n", __FUNCTION__);
+ s3c24xx_i2c_disable_irq(i2c);
+ goto out_ack;
+
+ case STATE_START:
+ /* last thing we did was send a start condition on the
+ * bus, or started a new i2c message
+ */
+
+ if (iicstat & S3C2410_IICSTAT_LASTBIT &&
+ !(i2c->msg->flags & I2C_M_IGNORE_NAK)) {
+ /* ack was not received... */
+
+ dev_dbg(i2c->dev, "ack was not received\n");
+ s3c24xx_i2c_stop(i2c, -EREMOTEIO);
+ goto out_ack;
+ }
+
+ if (i2c->msg->flags & I2C_M_RD)
+ i2c->state = STATE_READ;
+ else
+ i2c->state = STATE_WRITE;
+
+ /* terminate the transfer if there is nothing to do
+ * (used by the i2c probe to find devices */
+
+ if (is_lastmsg(i2c) && i2c->msg->len == 0) {
+ s3c24xx_i2c_stop(i2c, 0);
+ goto out_ack;
+ }
+
+ if (i2c->state == STATE_READ)
+ goto prepare_read;
+
+ /* fall through to the write state, as we will need to
+ * send a byte as well */
+
+ case STATE_WRITE:
+ /* we are writing data to the device... check for the
+ * end of the message, and if so, work out what to do
+ */
+
+ retry_write:
+ if (!is_msgend(i2c)) {
+ byte = i2c->msg->buf[i2c->msg_ptr++];
+ writeb(byte, i2c->regs + S3C2410_IICDS);
+
+ } else if (!is_lastmsg(i2c)) {
+ /* we need to go to the next i2c message */
+
+ dev_dbg(i2c->dev, "WRITE: Next Message\n");
+
+ i2c->msg_ptr = 0;
+ i2c->msg_idx ++;
+ i2c->msg++;
+
+ /* check to see if we need to do another message */
+ if (i2c->msg->flags & I2C_M_NOSTART) {
+
+ if (i2c->msg->flags & I2C_M_RD) {
+ /* cannot do this, the controller
+ * forces us to send a new START
+ * when we change direction */
+
+ s3c24xx_i2c_stop(i2c, -EINVAL);
+ }
+
+ goto retry_write;
+ } else {
+
+ /* send the new start */
+ s3c24xx_i2c_message_start(i2c, i2c->msg);
+ i2c->state = STATE_START;
+ }
+
+ } else {
+ /* send stop */
+
+ s3c24xx_i2c_stop(i2c, 0);
+ }
+ break;
+
+ case STATE_READ:
+ /* we have a byte of data in the data register, do
+ * something with it, and then work out wether we are
+ * going to do any more read/write
+ */
+
+ if (!(i2c->msg->flags & I2C_M_IGNORE_NAK) &&
+ !(is_msglast(i2c) && is_lastmsg(i2c))) {
+
+ if (iicstat & S3C2410_IICSTAT_LASTBIT) {
+ dev_dbg(i2c->dev, "READ: No Ack\n");
+
+ s3c24xx_i2c_stop(i2c, -ECONNREFUSED);
+ goto out_ack;
+ }
+ }
+
+ byte = readb(i2c->regs + S3C2410_IICDS);
+ i2c->msg->buf[i2c->msg_ptr++] = byte;
+
+ prepare_read:
+ if (is_msglast(i2c)) {
+ /* last byte of buffer */
+
+ if (is_lastmsg(i2c))
+ s3c24xx_i2c_disable_ack(i2c);
+
+ } else if (is_msgend(i2c)) {
+ /* ok, we've read the entire buffer, see if there
+ * is anything else we need to do */
+
+ if (is_lastmsg(i2c)) {
+ /* last message, send stop and complete */
+ dev_dbg(i2c->dev, "READ: Send Stop\n");
+
+ s3c24xx_i2c_stop(i2c, 0);
+ } else {
+ /* go to the next transfer */
+ dev_dbg(i2c->dev, "READ: Next Transfer\n");
+
+ i2c->msg_ptr = 0;
+ i2c->msg_idx++;
+ i2c->msg++;
+ }
+ }
+
+ break;
+ }
+
+ /* acknowlegde the IRQ and get back on with the work */
+
+ out_ack:
+ tmp = readl(i2c->regs + S3C2410_IICCON);
+ tmp &= ~S3C2410_IICCON_IRQPEND;
+ writel(tmp, i2c->regs + S3C2410_IICCON);
+ out:
+ return ret;
+}
+
+/* s3c24xx_i2c_irq
+ *
+ * top level IRQ servicing routine
+*/
+
+static irqreturn_t s3c24xx_i2c_irq(int irqno, void *dev_id,
+ struct pt_regs *regs)
+{
+ struct s3c24xx_i2c *i2c = dev_id;
+ unsigned long status;
+ unsigned long tmp;
+
+ status = readl(i2c->regs + S3C2410_IICSTAT);
+
+ if (status & S3C2410_IICSTAT_ARBITR) {
+ // deal with arbitration loss
+ dev_err(i2c->dev, "deal with arbitration loss\n");
+ }
+
+ if (i2c->state == STATE_IDLE) {
+ dev_dbg(i2c->dev, "IRQ: error i2c->state == IDLE\n");
+
+ tmp = readl(i2c->regs + S3C2410_IICCON);
+ tmp &= ~S3C2410_IICCON_IRQPEND;
+ writel(tmp, i2c->regs + S3C2410_IICCON);
+ goto out;
+ }
+
+ /* pretty much this leaves us with the fact that we've
+ * transmitted or received whatever byte we last sent */
+
+ i2s_s3c_irq_nextbyte(i2c, status);
+
+ out:
+ return IRQ_HANDLED;
+}
+
+
+/* s3c24xx_i2c_set_master
+ *
+ * get the i2c bus for a master transaction
+*/
+
+static int s3c24xx_i2c_set_master(struct s3c24xx_i2c *i2c)
+{
+ unsigned long iicstat;
+ int timeout = 400;
+
+ while (timeout-- > 0) {
+ iicstat = readl(i2c->regs + S3C2410_IICSTAT);
+
+ if (!(iicstat & S3C2410_IICSTAT_BUSBUSY))
+ return 0;
+
+ msleep(1);
+ }
+
+ dev_dbg(i2c->dev, "timeout: GPEDAT is %08x\n",
+ __raw_readl(S3C2410_GPEDAT));
+
+ return -ETIMEDOUT;
+}
+
+/* s3c24xx_i2c_doxfer
+ *
+ * this starts an i2c transfer
+*/
+
+static int s3c24xx_i2c_doxfer(struct s3c24xx_i2c *i2c, struct i2c_msg *msgs, int num)
+{
+ unsigned long timeout;
+ int ret;
+
+ ret = s3c24xx_i2c_set_master(i2c);
+ if (ret != 0) {
+ dev_err(i2c->dev, "cannot get bus (error %d)\n", ret);
+ ret = -EAGAIN;
+ goto out;
+ }
+
+ spin_lock_irq(&i2c->lock);
+
+ i2c->msg = msgs;
+ i2c->msg_num = num;
+ i2c->msg_ptr = 0;
+ i2c->msg_idx = 0;
+ i2c->state = STATE_START;
+
+ s3c24xx_i2c_enable_irq(i2c);
+ s3c24xx_i2c_message_start(i2c, msgs);
+ spin_unlock_irq(&i2c->lock);
+
+ timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
+
+ ret = i2c->msg_idx;
+
+ /* having these next two as dev_err() makes life very
+ * noisy when doing an i2cdetect */
+
+ if (timeout == 0)
+ dev_dbg(i2c->dev, "timeout\n");
+ else if (ret != num)
+ dev_dbg(i2c->dev, "incomplete xfer (%d)\n", ret);
+
+ /* ensure the stop has been through the bus */
+
+ msleep(1);
+
+ out:
+ return ret;
+}
+
+/* s3c24xx_i2c_xfer
+ *
+ * first port of call from the i2c bus code when an message needs
+ * transfering across the i2c bus.
+*/
+
+static int s3c24xx_i2c_xfer(struct i2c_adapter *adap,
+ struct i2c_msg *msgs, int num)
+{
+ struct s3c24xx_i2c *i2c = (struct s3c24xx_i2c *)adap->algo_data;
+ int retry;
+ int ret;
+
+ for (retry = 0; retry < adap->retries; retry++) {
+
+ ret = s3c24xx_i2c_doxfer(i2c, msgs, num);
+
+ if (ret != -EAGAIN)
+ return ret;
+
+ dev_dbg(i2c->dev, "Retrying transmission (%d)\n", retry);
+
+ udelay(100);
+ }
+
+ return -EREMOTEIO;
+}
+
+/* declare our i2c functionality */
+static u32 s3c24xx_i2c_func(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_PROTOCOL_MANGLING;
+}
+
+/* i2c bus registration info */
+
+static struct i2c_algorithm s3c24xx_i2c_algorithm = {
+ .name = "S3C2410-I2C-Algorithm",
+ .master_xfer = s3c24xx_i2c_xfer,
+ .functionality = s3c24xx_i2c_func,
+};
+
+static struct s3c24xx_i2c s3c24xx_i2c = {
+ .lock = SPIN_LOCK_UNLOCKED,
+ .wait = __WAIT_QUEUE_HEAD_INITIALIZER(s3c24xx_i2c.wait),
+ .adap = {
+ .name = "s3c2410-i2c",
+ .owner = THIS_MODULE,
+ .algo = &s3c24xx_i2c_algorithm,
+ .retries = 2,
+ .class = I2C_CLASS_HWMON,
+ },
+};
+
+/* s3c24xx_i2c_calcdivisor
+ *
+ * return the divisor settings for a given frequency
+*/
+
+static int s3c24xx_i2c_calcdivisor(unsigned long clkin, unsigned int wanted,
+ unsigned int *div1, unsigned int *divs)
+{
+ unsigned int calc_divs = clkin / wanted;
+ unsigned int calc_div1;
+
+ if (calc_divs > (16*16))
+ calc_div1 = 512;
+ else
+ calc_div1 = 16;
+
+ calc_divs += calc_div1-1;
+ calc_divs /= calc_div1;
+
+ if (calc_divs == 0)
+ calc_divs = 1;
+ if (calc_divs > 17)
+ calc_divs = 17;
+
+ *divs = calc_divs;
+ *div1 = calc_div1;
+
+ return clkin / (calc_divs * calc_div1);
+}
+
+/* freq_acceptable
+ *
+ * test wether a frequency is within the acceptable range of error
+*/
+
+static inline int freq_acceptable(unsigned int freq, unsigned int wanted)
+{
+ int diff = freq - wanted;
+
+ return (diff >= -2 && diff <= 2);
+}
+
+/* s3c24xx_i2c_getdivisor
+ *
+ * work out a divisor for the user requested frequency setting,
+ * either by the requested frequency, or scanning the acceptable
+ * range of frequencies until something is found
+*/
+
+static int s3c24xx_i2c_getdivisor(struct s3c24xx_i2c *i2c,
+ struct s3c2410_platform_i2c *pdata,
+ unsigned long *iicon,
+ unsigned int *got)
+{
+ unsigned long clkin = clk_get_rate(i2c->clk);
+
+ unsigned int divs, div1;
+ int freq;
+ int start, end;
+
+ clkin /= 1000; /* clkin now in KHz */
+
+ dev_dbg(i2c->dev, "pdata %p, freq %lu %lu..%lu\n",
+ pdata, pdata->bus_freq, pdata->min_freq, pdata->max_freq);
+
+ if (pdata->bus_freq != 0) {
+ freq = s3c24xx_i2c_calcdivisor(clkin, pdata->bus_freq/1000,
+ &div1, &divs);
+ if (freq_acceptable(freq, pdata->bus_freq/1000))
+ goto found;
+ }
+
+ /* ok, we may have to search for something suitable... */
+
+ start = (pdata->max_freq == 0) ? pdata->bus_freq : pdata->max_freq;
+ end = pdata->min_freq;
+
+ start /= 1000;
+ end /= 1000;
+
+ /* search loop... */
+
+ for (; start > end; start--) {
+ freq = s3c24xx_i2c_calcdivisor(clkin, start, &div1, &divs);
+ if (freq_acceptable(freq, start))
+ goto found;
+ }
+
+ /* cannot find frequency spec */
+
+ return -EINVAL;
+
+ found:
+ *got = freq;
+ *iicon |= (divs-1);
+ *iicon |= (div1 == 512) ? S3C2410_IICCON_TXDIV_512 : 0;
+ return 0;
+}
+
+/* s3c24xx_i2c_init
+ *
+ * initialise the controller, set the IO lines and frequency
+*/
+
+static int s3c24xx_i2c_init(struct s3c24xx_i2c *i2c)
+{
+ unsigned long iicon = S3C2410_IICCON_IRQEN | S3C2410_IICCON_ACKEN;
+ struct s3c2410_platform_i2c *pdata;
+ unsigned int freq;
+
+ /* get the plafrom data */
+
+ pdata = s3c24xx_i2c_get_platformdata(i2c->adap.dev.parent);
+
+ /* inititalise the gpio */
+
+ s3c2410_gpio_cfgpin(S3C2410_GPE15, S3C2410_GPE15_IICSDA);
+ s3c2410_gpio_cfgpin(S3C2410_GPE14, S3C2410_GPE14_IICSCL);
+
+ /* write slave address */
+
+ writeb(pdata->slave_addr, i2c->regs + S3C2410_IICADD);
+
+ dev_info(i2c->dev, "slave address 0x%02x\n", pdata->slave_addr);
+
+ /* we need to work out the divisors for the clock... */
+
+ if (s3c24xx_i2c_getdivisor(i2c, pdata, &iicon, &freq) != 0) {
+ dev_err(i2c->dev, "cannot meet bus frequency required\n");
+ return -EINVAL;
+ }
+
+ /* todo - check that the i2c lines aren't being dragged anywhere */
+
+ dev_info(i2c->dev, "bus frequency set to %d KHz\n", freq);
+ dev_dbg(i2c->dev, "S3C2410_IICCON=0x%02lx\n", iicon);
+
+ writel(iicon, i2c->regs + S3C2410_IICCON);
+
+ /* check for s3c2440 i2c controller */
+
+ if (s3c24xx_i2c_is2440(i2c)) {
+ dev_dbg(i2c->dev, "S3C2440_IICLC=%08x\n", pdata->sda_delay);
+
+ writel(pdata->sda_delay, i2c->regs + S3C2440_IICLC);
+ }
+
+ return 0;
+}
+
+static void s3c24xx_i2c_free(struct s3c24xx_i2c *i2c)
+{
+ if (i2c->clk != NULL && !IS_ERR(i2c->clk)) {
+ clk_disable(i2c->clk);
+ clk_unuse(i2c->clk);
+ clk_put(i2c->clk);
+ i2c->clk = NULL;
+ }
+
+ if (i2c->regs != NULL) {
+ iounmap(i2c->regs);
+ i2c->regs = NULL;
+ }
+
+ if (i2c->ioarea != NULL) {
+ release_resource(i2c->ioarea);
+ kfree(i2c->ioarea);
+ i2c->ioarea = NULL;
+ }
+}
+
+/* s3c24xx_i2c_probe
+ *
+ * called by the bus driver when a suitable device is found
+*/
+
+static int s3c24xx_i2c_probe(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct s3c24xx_i2c *i2c = &s3c24xx_i2c;
+ struct resource *res;
+ int ret;
+
+ /* find the clock and enable it */
+
+ i2c->dev = dev;
+ i2c->clk = clk_get(dev, "i2c");
+ if (IS_ERR(i2c->clk)) {
+ dev_err(dev, "cannot get clock\n");
+ ret = -ENOENT;
+ goto out;
+ }
+
+ dev_dbg(dev, "clock source %p\n", i2c->clk);
+
+ clk_use(i2c->clk);
+ clk_enable(i2c->clk);
+
+ /* map the registers */
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (res == NULL) {
+ dev_err(dev, "cannot find IO resource\n");
+ ret = -ENOENT;
+ goto out;
+ }
+
+ i2c->ioarea = request_mem_region(res->start, (res->end-res->start)+1,
+ pdev->name);
+
+ if (i2c->ioarea == NULL) {
+ dev_err(dev, "cannot request IO\n");
+ ret = -ENXIO;
+ goto out;
+ }
+
+ i2c->regs = ioremap(res->start, (res->end-res->start)+1);
+
+ if (i2c->regs == NULL) {
+ dev_err(dev, "cannot map IO\n");
+ ret = -ENXIO;
+ goto out;
+ }
+
+ dev_dbg(dev, "registers %p (%p, %p)\n", i2c->regs, i2c->ioarea, res);
+
+ /* setup info block for the i2c core */
+
+ i2c->adap.algo_data = i2c;
+ i2c->adap.dev.parent = dev;
+
+ /* initialise the i2c controller */
+
+ ret = s3c24xx_i2c_init(i2c);
+ if (ret != 0)
+ goto out;
+
+ /* find the IRQ for this unit (note, this relies on the init call to
+ * ensure no current IRQs pending
+ */
+
+ res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+ if (res == NULL) {
+ dev_err(dev, "cannot find IRQ\n");
+ ret = -ENOENT;
+ goto out;
+ }
+
+ ret = request_irq(res->start, s3c24xx_i2c_irq, SA_INTERRUPT,
+ pdev->name, i2c);
+
+ if (ret != 0) {
+ dev_err(dev, "cannot claim IRQ\n");
+ goto out;
+ }
+
+ i2c->irq = res;
+
+ dev_dbg(dev, "irq resource %p (%ld)\n", res, res->start);
+
+ ret = i2c_add_adapter(&i2c->adap);
+ if (ret < 0) {
+ dev_err(dev, "failed to add bus to i2c core\n");
+ goto out;
+ }
+
+ dev_set_drvdata(dev, i2c);
+
+ dev_info(dev, "%s: S3C I2C adapter\n", i2c->adap.dev.bus_id);
+
+ out:
+ if (ret < 0)
+ s3c24xx_i2c_free(i2c);
+
+ return ret;
+}
+
+/* s3c24xx_i2c_remove
+ *
+ * called when device is removed from the bus
+*/
+
+static int s3c24xx_i2c_remove(struct device *dev)
+{
+ struct s3c24xx_i2c *i2c = dev_get_drvdata(dev);
+
+ if (i2c != NULL) {
+ s3c24xx_i2c_free(i2c);
+ dev_set_drvdata(dev, NULL);
+ }
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int s3c24xx_i2c_resume(struct device *dev, u32 level)
+{
+ struct s3c24xx_i2c *i2c = dev_get_drvdata(dev);
+
+ if (i2c != NULL && level == RESUME_ENABLE) {
+ dev_dbg(dev, "resume: level %d\n", level);
+ s3c24xx_i2c_init(i2c);
+ }
+
+ return 0;
+}
+
+#else
+#define s3c24xx_i2c_resume NULL
+#endif
+
+/* device driver for platform bus bits */
+
+static struct device_driver s3c2410_i2c_driver = {
+ .name = "s3c2410-i2c",
+ .bus = &platform_bus_type,
+ .probe = s3c24xx_i2c_probe,
+ .remove = s3c24xx_i2c_remove,
+ .resume = s3c24xx_i2c_resume,
+};
+
+static struct device_driver s3c2440_i2c_driver = {
+ .name = "s3c2440-i2c",
+ .bus = &platform_bus_type,
+ .probe = s3c24xx_i2c_probe,
+ .remove = s3c24xx_i2c_remove,
+ .resume = s3c24xx_i2c_resume,
+};
+
+static int __init i2c_adap_s3c_init(void)
+{
+ int ret;
+
+ ret = driver_register(&s3c2410_i2c_driver);
+ if (ret == 0)
+ ret = driver_register(&s3c2440_i2c_driver);
+
+ return ret;
+}
+
+static void __exit i2c_adap_s3c_exit(void)
+{
+ driver_unregister(&s3c2410_i2c_driver);
+ driver_unregister(&s3c2440_i2c_driver);
+}
+
+module_init(i2c_adap_s3c_init);
+module_exit(i2c_adap_s3c_exit);
+
+MODULE_DESCRIPTION("S3C24XX I2C Bus driver");
+MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>");
+MODULE_LICENSE("GPL");
generated by cgit v1.2.3-58-ga151 (git 2.39.0) at 2024-11-24 21:54:46 +0000