diff options
Diffstat (limited to 'ANDROID_3.4.5/drivers/i2c/busses/i2c-s3c2410.c')
| -rw-r--r-- | ANDROID_3.4.5/drivers/i2c/busses/i2c-s3c2410.c | 1161 |
1 files changed, 0 insertions, 1161 deletions
diff --git a/ANDROID_3.4.5/drivers/i2c/busses/i2c-s3c2410.c b/ANDROID_3.4.5/drivers/i2c/busses/i2c-s3c2410.c deleted file mode 100644 index 737f7218..00000000 --- a/ANDROID_3.4.5/drivers/i2c/busses/i2c-s3c2410.c +++ /dev/null @@ -1,1161 +0,0 @@ -/* linux/drivers/i2c/busses/i2c-s3c2410.c - * - * Copyright (C) 2004,2005,2009 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/init.h> -#include <linux/time.h> -#include <linux/interrupt.h> -#include <linux/delay.h> -#include <linux/errno.h> -#include <linux/err.h> -#include <linux/platform_device.h> -#include <linux/pm_runtime.h> -#include <linux/clk.h> -#include <linux/cpufreq.h> -#include <linux/slab.h> -#include <linux/io.h> -#include <linux/of_i2c.h> -#include <linux/of_gpio.h> - -#include <asm/irq.h> - -#include <plat/regs-iic.h> -#include <plat/iic.h> - -/* i2c controller state */ - -enum s3c24xx_i2c_state { - STATE_IDLE, - STATE_START, - STATE_READ, - STATE_WRITE, - STATE_STOP -}; - -enum s3c24xx_i2c_type { - TYPE_S3C2410, - TYPE_S3C2440, -}; - -struct s3c24xx_i2c { - spinlock_t lock; - wait_queue_head_t wait; - unsigned int suspended:1; - - struct i2c_msg *msg; - unsigned int msg_num; - unsigned int msg_idx; - unsigned int msg_ptr; - - unsigned int tx_setup; - unsigned int irq; - - enum s3c24xx_i2c_state state; - unsigned long clkrate; - - void __iomem *regs; - struct clk *clk; - struct device *dev; - struct resource *ioarea; - struct i2c_adapter adap; - - struct s3c2410_platform_i2c *pdata; - int gpios[2]; -#ifdef CONFIG_CPU_FREQ - struct notifier_block freq_transition; -#endif -}; - -/* default platform data removed, dev should always carry data. */ - -/* 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); - enum s3c24xx_i2c_type type; - -#ifdef CONFIG_OF - if (i2c->dev->of_node) - return of_device_is_compatible(i2c->dev->of_node, - "samsung,s3c2440-i2c"); -#endif - - type = platform_get_device_id(pdev)->driver_data; - return type == TYPE_S3C2440; -} - -/* 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 here to ensure the data byte has gotten onto the bus - * before the transaction is started */ - - ndelay(i2c->tx_setup); - - 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; -} - -/* i2c_s3c_irq_nextbyte - * - * process an interrupt and work out what to do - */ - -static int i2c_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", __func__); - goto out; - - case STATE_STOP: - dev_err(i2c->dev, "%s: called in STATE_STOP\n", __func__); - 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, -ENXIO); - 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 - * as this is 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 - */ - - if (!(i2c->msg->flags & I2C_M_IGNORE_NAK)) { - if (iicstat & S3C2410_IICSTAT_LASTBIT) { - dev_dbg(i2c->dev, "WRITE: No Ack\n"); - - s3c24xx_i2c_stop(i2c, -ECONNREFUSED); - goto out_ack; - } - } - - retry_write: - - if (!is_msgend(i2c)) { - byte = i2c->msg->buf[i2c->msg_ptr++]; - writeb(byte, i2c->regs + S3C2410_IICDS); - - /* delay after writing the byte to allow the - * data setup time on the bus, as writing the - * data to the register causes the first bit - * to appear on SDA, and SCL will change as - * soon as the interrupt is acknowledged */ - - ndelay(i2c->tx_setup); - - } 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 - */ - - 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 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 */ - - i2c_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); - } - - 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 iicstat, timeout; - int spins = 20; - int ret; - - if (i2c->suspended) - return -EIO; - - 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 */ - - dev_dbg(i2c->dev, "waiting for bus idle\n"); - - /* first, try busy waiting briefly */ - do { - cpu_relax(); - iicstat = readl(i2c->regs + S3C2410_IICSTAT); - } while ((iicstat & S3C2410_IICSTAT_START) && --spins); - - /* if that timed out sleep */ - if (!spins) { - msleep(1); - iicstat = readl(i2c->regs + S3C2410_IICSTAT); - } - - if (iicstat & S3C2410_IICSTAT_START) - dev_warn(i2c->dev, "timeout waiting for bus idle\n"); - - out: - return ret; -} - -/* s3c24xx_i2c_xfer - * - * first port of call from the i2c bus code when an message needs - * transferring 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; - - pm_runtime_get_sync(&adap->dev); - clk_enable(i2c->clk); - - for (retry = 0; retry < adap->retries; retry++) { - - ret = s3c24xx_i2c_doxfer(i2c, msgs, num); - - if (ret != -EAGAIN) { - clk_disable(i2c->clk); - pm_runtime_put_sync(&adap->dev); - return ret; - } - - dev_dbg(i2c->dev, "Retrying transmission (%d)\n", retry); - - udelay(100); - } - - clk_disable(i2c->clk); - pm_runtime_put_sync(&adap->dev); - 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 const struct i2c_algorithm s3c24xx_i2c_algorithm = { - .master_xfer = s3c24xx_i2c_xfer, - .functionality = s3c24xx_i2c_func, -}; - -/* 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); -} - -/* s3c24xx_i2c_clockrate - * - * 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_clockrate(struct s3c24xx_i2c *i2c, unsigned int *got) -{ - struct s3c2410_platform_i2c *pdata = i2c->pdata; - unsigned long clkin = clk_get_rate(i2c->clk); - unsigned int divs, div1; - unsigned long target_frequency; - u32 iiccon; - int freq; - - i2c->clkrate = clkin; - clkin /= 1000; /* clkin now in KHz */ - - dev_dbg(i2c->dev, "pdata desired frequency %lu\n", pdata->frequency); - - target_frequency = pdata->frequency ? pdata->frequency : 100000; - - target_frequency /= 1000; /* Target frequency now in KHz */ - - freq = s3c24xx_i2c_calcdivisor(clkin, target_frequency, &div1, &divs); - - if (freq > target_frequency) { - dev_err(i2c->dev, - "Unable to achieve desired frequency %luKHz." \ - " Lowest achievable %dKHz\n", target_frequency, freq); - return -EINVAL; - } - - *got = freq; - - iiccon = readl(i2c->regs + S3C2410_IICCON); - iiccon &= ~(S3C2410_IICCON_SCALEMASK | S3C2410_IICCON_TXDIV_512); - iiccon |= (divs-1); - - if (div1 == 512) - iiccon |= S3C2410_IICCON_TXDIV_512; - - writel(iiccon, i2c->regs + S3C2410_IICCON); - - if (s3c24xx_i2c_is2440(i2c)) { - unsigned long sda_delay; - - if (pdata->sda_delay) { - sda_delay = clkin * pdata->sda_delay; - sda_delay = DIV_ROUND_UP(sda_delay, 1000000); - sda_delay = DIV_ROUND_UP(sda_delay, 5); - if (sda_delay > 3) - sda_delay = 3; - sda_delay |= S3C2410_IICLC_FILTER_ON; - } else - sda_delay = 0; - - dev_dbg(i2c->dev, "IICLC=%08lx\n", sda_delay); - writel(sda_delay, i2c->regs + S3C2440_IICLC); - } - - return 0; -} - -#ifdef CONFIG_CPU_FREQ - -#define freq_to_i2c(_n) container_of(_n, struct s3c24xx_i2c, freq_transition) - -static int s3c24xx_i2c_cpufreq_transition(struct notifier_block *nb, - unsigned long val, void *data) -{ - struct s3c24xx_i2c *i2c = freq_to_i2c(nb); - unsigned long flags; - unsigned int got; - int delta_f; - int ret; - - delta_f = clk_get_rate(i2c->clk) - i2c->clkrate; - - /* if we're post-change and the input clock has slowed down - * or at pre-change and the clock is about to speed up, then - * adjust our clock rate. <0 is slow, >0 speedup. - */ - - if ((val == CPUFREQ_POSTCHANGE && delta_f < 0) || - (val == CPUFREQ_PRECHANGE && delta_f > 0)) { - spin_lock_irqsave(&i2c->lock, flags); - ret = s3c24xx_i2c_clockrate(i2c, &got); - spin_unlock_irqrestore(&i2c->lock, flags); - - if (ret < 0) - dev_err(i2c->dev, "cannot find frequency\n"); - else - dev_info(i2c->dev, "setting freq %d\n", got); - } - - return 0; -} - -static inline int s3c24xx_i2c_register_cpufreq(struct s3c24xx_i2c *i2c) -{ - i2c->freq_transition.notifier_call = s3c24xx_i2c_cpufreq_transition; - - return cpufreq_register_notifier(&i2c->freq_transition, - CPUFREQ_TRANSITION_NOTIFIER); -} - -static inline void s3c24xx_i2c_deregister_cpufreq(struct s3c24xx_i2c *i2c) -{ - cpufreq_unregister_notifier(&i2c->freq_transition, - CPUFREQ_TRANSITION_NOTIFIER); -} - -#else -static inline int s3c24xx_i2c_register_cpufreq(struct s3c24xx_i2c *i2c) -{ - return 0; -} - -static inline void s3c24xx_i2c_deregister_cpufreq(struct s3c24xx_i2c *i2c) -{ -} -#endif - -#ifdef CONFIG_OF -static int s3c24xx_i2c_parse_dt_gpio(struct s3c24xx_i2c *i2c) -{ - int idx, gpio, ret; - - for (idx = 0; idx < 2; idx++) { - gpio = of_get_gpio(i2c->dev->of_node, idx); - if (!gpio_is_valid(gpio)) { - dev_err(i2c->dev, "invalid gpio[%d]: %d\n", idx, gpio); - goto free_gpio; - } - - ret = gpio_request(gpio, "i2c-bus"); - if (ret) { - dev_err(i2c->dev, "gpio [%d] request failed\n", gpio); - goto free_gpio; - } - } - return 0; - -free_gpio: - while (--idx >= 0) - gpio_free(i2c->gpios[idx]); - return -EINVAL; -} - -static void s3c24xx_i2c_dt_gpio_free(struct s3c24xx_i2c *i2c) -{ - unsigned int idx; - for (idx = 0; idx < 2; idx++) - gpio_free(i2c->gpios[idx]); -} -#else -static int s3c24xx_i2c_parse_dt_gpio(struct s3c24xx_i2c *i2c) -{ - return 0; -} - -static void s3c24xx_i2c_dt_gpio_free(struct s3c24xx_i2c *i2c) -{ -} -#endif - -/* 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 = i2c->pdata; - - /* inititalise the gpio */ - - if (pdata->cfg_gpio) - pdata->cfg_gpio(to_platform_device(i2c->dev)); - else - if (s3c24xx_i2c_parse_dt_gpio(i2c)) - return -EINVAL; - - /* write slave address */ - - writeb(pdata->slave_addr, i2c->regs + S3C2410_IICADD); - - dev_info(i2c->dev, "slave address 0x%02x\n", pdata->slave_addr); - - writel(iicon, i2c->regs + S3C2410_IICCON); - - /* we need to work out the divisors for the clock... */ - - if (s3c24xx_i2c_clockrate(i2c, &freq) != 0) { - writel(0, i2c->regs + S3C2410_IICCON); - 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); - - return 0; -} - -#ifdef CONFIG_OF -/* s3c24xx_i2c_parse_dt - * - * Parse the device tree node and retreive the platform data. -*/ - -static void -s3c24xx_i2c_parse_dt(struct device_node *np, struct s3c24xx_i2c *i2c) -{ - struct s3c2410_platform_i2c *pdata = i2c->pdata; - - if (!np) - return; - - pdata->bus_num = -1; /* i2c bus number is dynamically assigned */ - of_property_read_u32(np, "samsung,i2c-sda-delay", &pdata->sda_delay); - of_property_read_u32(np, "samsung,i2c-slave-addr", &pdata->slave_addr); - of_property_read_u32(np, "samsung,i2c-max-bus-freq", - (u32 *)&pdata->frequency); -} -#else -static void -s3c24xx_i2c_parse_dt(struct device_node *np, struct s3c24xx_i2c *i2c) -{ - return; -} -#endif - -/* s3c24xx_i2c_probe - * - * called by the bus driver when a suitable device is found -*/ - -static int s3c24xx_i2c_probe(struct platform_device *pdev) -{ - struct s3c24xx_i2c *i2c; - struct s3c2410_platform_i2c *pdata = NULL; - struct resource *res; - int ret; - - if (!pdev->dev.of_node) { - pdata = pdev->dev.platform_data; - if (!pdata) { - dev_err(&pdev->dev, "no platform data\n"); - return -EINVAL; - } - } - - i2c = devm_kzalloc(&pdev->dev, sizeof(struct s3c24xx_i2c), GFP_KERNEL); - if (!i2c) { - dev_err(&pdev->dev, "no memory for state\n"); - return -ENOMEM; - } - - i2c->pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); - if (!i2c->pdata) { - ret = -ENOMEM; - goto err_noclk; - } - - if (pdata) - memcpy(i2c->pdata, pdata, sizeof(*pdata)); - else - s3c24xx_i2c_parse_dt(pdev->dev.of_node, i2c); - - strlcpy(i2c->adap.name, "s3c2410-i2c", sizeof(i2c->adap.name)); - i2c->adap.owner = THIS_MODULE; - i2c->adap.algo = &s3c24xx_i2c_algorithm; - i2c->adap.retries = 2; - i2c->adap.class = I2C_CLASS_HWMON | I2C_CLASS_SPD; - i2c->tx_setup = 50; - - spin_lock_init(&i2c->lock); - init_waitqueue_head(&i2c->wait); - - /* find the clock and enable it */ - - i2c->dev = &pdev->dev; - i2c->clk = clk_get(&pdev->dev, "i2c"); - if (IS_ERR(i2c->clk)) { - dev_err(&pdev->dev, "cannot get clock\n"); - ret = -ENOENT; - goto err_noclk; - } - - dev_dbg(&pdev->dev, "clock source %p\n", i2c->clk); - - clk_enable(i2c->clk); - - /* map the registers */ - - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (res == NULL) { - dev_err(&pdev->dev, "cannot find IO resource\n"); - ret = -ENOENT; - goto err_clk; - } - - i2c->ioarea = request_mem_region(res->start, resource_size(res), - pdev->name); - - if (i2c->ioarea == NULL) { - dev_err(&pdev->dev, "cannot request IO\n"); - ret = -ENXIO; - goto err_clk; - } - - i2c->regs = ioremap(res->start, resource_size(res)); - - if (i2c->regs == NULL) { - dev_err(&pdev->dev, "cannot map IO\n"); - ret = -ENXIO; - goto err_ioarea; - } - - dev_dbg(&pdev->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 = &pdev->dev; - - /* initialise the i2c controller */ - - ret = s3c24xx_i2c_init(i2c); - if (ret != 0) - goto err_iomap; - - /* find the IRQ for this unit (note, this relies on the init call to - * ensure no current IRQs pending - */ - - i2c->irq = ret = platform_get_irq(pdev, 0); - if (ret <= 0) { - dev_err(&pdev->dev, "cannot find IRQ\n"); - goto err_iomap; - } - - ret = request_irq(i2c->irq, s3c24xx_i2c_irq, 0, - dev_name(&pdev->dev), i2c); - - if (ret != 0) { - dev_err(&pdev->dev, "cannot claim IRQ %d\n", i2c->irq); - goto err_iomap; - } - - ret = s3c24xx_i2c_register_cpufreq(i2c); - if (ret < 0) { - dev_err(&pdev->dev, "failed to register cpufreq notifier\n"); - goto err_irq; - } - - /* Note, previous versions of the driver used i2c_add_adapter() - * to add the bus at any number. We now pass the bus number via - * the platform data, so if unset it will now default to always - * being bus 0. - */ - - i2c->adap.nr = i2c->pdata->bus_num; - i2c->adap.dev.of_node = pdev->dev.of_node; - - ret = i2c_add_numbered_adapter(&i2c->adap); - if (ret < 0) { - dev_err(&pdev->dev, "failed to add bus to i2c core\n"); - goto err_cpufreq; - } - - of_i2c_register_devices(&i2c->adap); - platform_set_drvdata(pdev, i2c); - - pm_runtime_enable(&pdev->dev); - pm_runtime_enable(&i2c->adap.dev); - - dev_info(&pdev->dev, "%s: S3C I2C adapter\n", dev_name(&i2c->adap.dev)); - clk_disable(i2c->clk); - return 0; - - err_cpufreq: - s3c24xx_i2c_deregister_cpufreq(i2c); - - err_irq: - free_irq(i2c->irq, i2c); - - err_iomap: - iounmap(i2c->regs); - - err_ioarea: - release_resource(i2c->ioarea); - kfree(i2c->ioarea); - - err_clk: - clk_disable(i2c->clk); - clk_put(i2c->clk); - - err_noclk: - return ret; -} - -/* s3c24xx_i2c_remove - * - * called when device is removed from the bus -*/ - -static int s3c24xx_i2c_remove(struct platform_device *pdev) -{ - struct s3c24xx_i2c *i2c = platform_get_drvdata(pdev); - - pm_runtime_disable(&i2c->adap.dev); - pm_runtime_disable(&pdev->dev); - - s3c24xx_i2c_deregister_cpufreq(i2c); - - i2c_del_adapter(&i2c->adap); - free_irq(i2c->irq, i2c); - - clk_disable(i2c->clk); - clk_put(i2c->clk); - - iounmap(i2c->regs); - - release_resource(i2c->ioarea); - s3c24xx_i2c_dt_gpio_free(i2c); - kfree(i2c->ioarea); - - return 0; -} - -#ifdef CONFIG_PM -static int s3c24xx_i2c_suspend_noirq(struct device *dev) -{ - struct platform_device *pdev = to_platform_device(dev); - struct s3c24xx_i2c *i2c = platform_get_drvdata(pdev); - - i2c->suspended = 1; - - return 0; -} - -static int s3c24xx_i2c_resume(struct device *dev) -{ - struct platform_device *pdev = to_platform_device(dev); - struct s3c24xx_i2c *i2c = platform_get_drvdata(pdev); - - i2c->suspended = 0; - clk_enable(i2c->clk); - s3c24xx_i2c_init(i2c); - clk_disable(i2c->clk); - - return 0; -} - -static const struct dev_pm_ops s3c24xx_i2c_dev_pm_ops = { - .suspend_noirq = s3c24xx_i2c_suspend_noirq, - .resume = s3c24xx_i2c_resume, -}; - -#define S3C24XX_DEV_PM_OPS (&s3c24xx_i2c_dev_pm_ops) -#else -#define S3C24XX_DEV_PM_OPS NULL -#endif - -/* device driver for platform bus bits */ - -static struct platform_device_id s3c24xx_driver_ids[] = { - { - .name = "s3c2410-i2c", - .driver_data = TYPE_S3C2410, - }, { - .name = "s3c2440-i2c", - .driver_data = TYPE_S3C2440, - }, { }, -}; -MODULE_DEVICE_TABLE(platform, s3c24xx_driver_ids); - -#ifdef CONFIG_OF -static const struct of_device_id s3c24xx_i2c_match[] = { - { .compatible = "samsung,s3c2410-i2c" }, - { .compatible = "samsung,s3c2440-i2c" }, - {}, -}; -MODULE_DEVICE_TABLE(of, s3c24xx_i2c_match); -#else -#define s3c24xx_i2c_match NULL -#endif - -static struct platform_driver s3c24xx_i2c_driver = { - .probe = s3c24xx_i2c_probe, - .remove = s3c24xx_i2c_remove, - .id_table = s3c24xx_driver_ids, - .driver = { - .owner = THIS_MODULE, - .name = "s3c-i2c", - .pm = S3C24XX_DEV_PM_OPS, - .of_match_table = s3c24xx_i2c_match, - }, -}; - -static int __init i2c_adap_s3c_init(void) -{ - return platform_driver_register(&s3c24xx_i2c_driver); -} -subsys_initcall(i2c_adap_s3c_init); - -static void __exit i2c_adap_s3c_exit(void) -{ - platform_driver_unregister(&s3c24xx_i2c_driver); -} -module_exit(i2c_adap_s3c_exit); - -MODULE_DESCRIPTION("S3C24XX I2C Bus driver"); -MODULE_AUTHOR("Ben Dooks, <ben@simtec.co.uk>"); -MODULE_LICENSE("GPL"); |