i2c: New driver for the SuperH Mobile I2C bus controller
This is V5 of the SuperH Mobile I2C Controller Driver. A simple Master only driver for the I2C block included in processors such as sh7343, sh7722 and sh7723. Tested on a sh7722 MigoR using a rs5c732b rtc. Signed-off-by: Magnus Damm <damm@igel.co.jp> Signed-off-by: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Jean Delvare <khali@linux-fr.org>
This commit is contained in:
Magnus Damm
Jean Delvare
parent
dec1a998bd
commit
da672773d8
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@ -695,4 +695,14 @@ config I2C_SH7760
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This driver can also be built as a module. If so, the module
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will be called i2c-sh7760.
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config I2C_SH_MOBILE
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tristate "SuperH Mobile I2C Controller"
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depends on SUPERH
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help
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If you say yes to this option, support will be included for the
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built-in I2C interface on the Renesas SH-Mobile processor.
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This driver can also be built as a module. If so, the module
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will be called i2c-sh_mobile.
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endmenu
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@ -39,6 +39,7 @@ obj-$(CONFIG_I2C_PXA) += i2c-pxa.o
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obj-$(CONFIG_I2C_S3C2410) += i2c-s3c2410.o
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obj-$(CONFIG_I2C_SAVAGE4) += i2c-savage4.o
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obj-$(CONFIG_I2C_SH7760) += i2c-sh7760.o
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obj-$(CONFIG_I2C_SH_MOBILE) += i2c-sh_mobile.o
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obj-$(CONFIG_I2C_SIBYTE) += i2c-sibyte.o
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obj-$(CONFIG_I2C_SIMTEC) += i2c-simtec.o
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obj-$(CONFIG_I2C_SIS5595) += i2c-sis5595.o
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500
drivers/i2c/busses/i2c-sh_mobile.c
Normal file
500
drivers/i2c/busses/i2c-sh_mobile.c
Normal file
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@ -0,0 +1,500 @@
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/*
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* SuperH Mobile I2C Controller
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*
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* Copyright (C) 2008 Magnus Damm
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*
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* Portions of the code based on out-of-tree driver i2c-sh7343.c
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* Copyright (c) 2006 Carlos Munoz <carlos@kenati.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/delay.h>
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#include <linux/platform_device.h>
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#include <linux/interrupt.h>
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#include <linux/i2c.h>
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#include <linux/err.h>
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#include <linux/clk.h>
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#include <linux/io.h>
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enum sh_mobile_i2c_op {
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OP_START = 0,
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OP_TX_ONLY,
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OP_TX_STOP,
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OP_TX_TO_RX,
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OP_RX_ONLY,
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OP_RX_STOP,
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};
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struct sh_mobile_i2c_data {
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struct device *dev;
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void __iomem *reg;
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struct i2c_adapter adap;
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struct clk *clk;
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u_int8_t iccl;
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u_int8_t icch;
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spinlock_t lock;
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wait_queue_head_t wait;
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struct i2c_msg *msg;
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int pos;
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int sr;
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};
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#define NORMAL_SPEED 100000 /* FAST_SPEED 400000 */
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/* Register offsets */
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#define ICDR(pd) (pd->reg + 0x00)
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#define ICCR(pd) (pd->reg + 0x04)
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#define ICSR(pd) (pd->reg + 0x08)
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#define ICIC(pd) (pd->reg + 0x0c)
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#define ICCL(pd) (pd->reg + 0x10)
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#define ICCH(pd) (pd->reg + 0x14)
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/* Register bits */
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#define ICCR_ICE 0x80
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#define ICCR_RACK 0x40
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#define ICCR_TRS 0x10
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#define ICCR_BBSY 0x04
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#define ICCR_SCP 0x01
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#define ICSR_SCLM 0x80
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#define ICSR_SDAM 0x40
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#define SW_DONE 0x20
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#define ICSR_BUSY 0x10
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#define ICSR_AL 0x08
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#define ICSR_TACK 0x04
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#define ICSR_WAIT 0x02
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#define ICSR_DTE 0x01
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#define ICIC_ALE 0x08
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#define ICIC_TACKE 0x04
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#define ICIC_WAITE 0x02
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#define ICIC_DTEE 0x01
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static void activate_ch(struct sh_mobile_i2c_data *pd)
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{
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/* Make sure the clock is enabled */
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clk_enable(pd->clk);
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/* Enable channel and configure rx ack */
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iowrite8(ioread8(ICCR(pd)) | ICCR_ICE, ICCR(pd));
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/* Mask all interrupts */
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iowrite8(0, ICIC(pd));
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/* Set the clock */
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iowrite8(pd->iccl, ICCL(pd));
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iowrite8(pd->icch, ICCH(pd));
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}
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static void deactivate_ch(struct sh_mobile_i2c_data *pd)
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{
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/* Clear/disable interrupts */
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iowrite8(0, ICSR(pd));
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iowrite8(0, ICIC(pd));
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/* Disable channel */
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iowrite8(ioread8(ICCR(pd)) & ~ICCR_ICE, ICCR(pd));
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/* Disable clock */
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clk_disable(pd->clk);
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}
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static unsigned char i2c_op(struct sh_mobile_i2c_data *pd,
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enum sh_mobile_i2c_op op, unsigned char data)
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{
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unsigned char ret = 0;
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unsigned long flags;
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dev_dbg(pd->dev, "op %d, data in 0x%02x\n", op, data);
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spin_lock_irqsave(&pd->lock, flags);
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switch (op) {
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case OP_START:
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iowrite8(0x94, ICCR(pd));
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break;
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case OP_TX_ONLY:
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iowrite8(data, ICDR(pd));
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break;
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case OP_TX_STOP:
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iowrite8(data, ICDR(pd));
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iowrite8(0x90, ICCR(pd));
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iowrite8(ICIC_ALE | ICIC_TACKE, ICIC(pd));
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break;
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case OP_TX_TO_RX:
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iowrite8(data, ICDR(pd));
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iowrite8(0x81, ICCR(pd));
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break;
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case OP_RX_ONLY:
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ret = ioread8(ICDR(pd));
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break;
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case OP_RX_STOP:
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ret = ioread8(ICDR(pd));
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iowrite8(0xc0, ICCR(pd));
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break;
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}
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spin_unlock_irqrestore(&pd->lock, flags);
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dev_dbg(pd->dev, "op %d, data out 0x%02x\n", op, ret);
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return ret;
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}
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static irqreturn_t sh_mobile_i2c_isr(int irq, void *dev_id)
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{
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struct platform_device *dev = dev_id;
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struct sh_mobile_i2c_data *pd = platform_get_drvdata(dev);
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struct i2c_msg *msg = pd->msg;
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unsigned char data, sr;
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int wakeup = 0;
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sr = ioread8(ICSR(pd));
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pd->sr |= sr;
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dev_dbg(pd->dev, "i2c_isr 0x%02x 0x%02x %s %d %d!\n", sr, pd->sr,
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(msg->flags & I2C_M_RD) ? "read" : "write",
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pd->pos, msg->len);
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if (sr & (ICSR_AL | ICSR_TACK)) {
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iowrite8(0, ICIC(pd)); /* disable interrupts */
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wakeup = 1;
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goto do_wakeup;
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}
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if (pd->pos == msg->len) {
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i2c_op(pd, OP_RX_ONLY, 0);
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wakeup = 1;
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goto do_wakeup;
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}
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if (pd->pos == -1) {
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data = (msg->addr & 0x7f) << 1;
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data |= (msg->flags & I2C_M_RD) ? 1 : 0;
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} else
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data = msg->buf[pd->pos];
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if ((pd->pos == -1) || !(msg->flags & I2C_M_RD)) {
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if (msg->flags & I2C_M_RD)
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i2c_op(pd, OP_TX_TO_RX, data);
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else if (pd->pos == (msg->len - 1)) {
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i2c_op(pd, OP_TX_STOP, data);
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wakeup = 1;
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} else
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i2c_op(pd, OP_TX_ONLY, data);
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} else {
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if (pd->pos == (msg->len - 1))
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data = i2c_op(pd, OP_RX_STOP, 0);
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else
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data = i2c_op(pd, OP_RX_ONLY, 0);
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msg->buf[pd->pos] = data;
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}
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pd->pos++;
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do_wakeup:
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if (wakeup) {
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pd->sr |= SW_DONE;
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wake_up(&pd->wait);
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}
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return IRQ_HANDLED;
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}
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static int start_ch(struct sh_mobile_i2c_data *pd, struct i2c_msg *usr_msg)
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{
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/* Initialize channel registers */
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iowrite8(ioread8(ICCR(pd)) & ~ICCR_ICE, ICCR(pd));
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/* Enable channel and configure rx ack */
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iowrite8(ioread8(ICCR(pd)) | ICCR_ICE, ICCR(pd));
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/* Set the clock */
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iowrite8(pd->iccl, ICCL(pd));
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iowrite8(pd->icch, ICCH(pd));
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pd->msg = usr_msg;
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pd->pos = -1;
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pd->sr = 0;
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/* Enable all interrupts except wait */
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iowrite8(ioread8(ICIC(pd)) | ICIC_ALE | ICIC_TACKE | ICIC_DTEE,
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ICIC(pd));
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return 0;
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}
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static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter,
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struct i2c_msg *msgs,
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int num)
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{
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struct sh_mobile_i2c_data *pd = i2c_get_adapdata(adapter);
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struct i2c_msg *msg;
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int err = 0;
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u_int8_t val;
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int i, k, retry_count;
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activate_ch(pd);
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/* Process all messages */
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for (i = 0; i < num; i++) {
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msg = &msgs[i];
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err = start_ch(pd, msg);
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if (err)
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break;
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i2c_op(pd, OP_START, 0);
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/* The interrupt handler takes care of the rest... */
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k = wait_event_timeout(pd->wait,
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pd->sr & (ICSR_TACK | SW_DONE),
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5 * HZ);
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if (!k)
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dev_err(pd->dev, "Transfer request timed out\n");
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retry_count = 10;
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again:
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val = ioread8(ICSR(pd));
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dev_dbg(pd->dev, "val 0x%02x pd->sr 0x%02x\n", val, pd->sr);
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if ((val | pd->sr) & (ICSR_TACK | ICSR_AL)) {
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err = -EIO;
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break;
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}
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/* the interrupt handler may wake us up before the
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* transfer is finished, so poll the hardware
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* until we're done.
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*/
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if (!(!(val & ICSR_BUSY) && (val & ICSR_SCLM) &&
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(val & ICSR_SDAM))) {
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msleep(1);
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if (retry_count--)
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goto again;
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err = -EIO;
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dev_err(pd->dev, "Polling timed out\n");
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break;
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}
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}
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deactivate_ch(pd);
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if (!err)
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err = num;
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return err;
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}
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static u32 sh_mobile_i2c_func(struct i2c_adapter *adapter)
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{
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return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
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}
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static struct i2c_algorithm sh_mobile_i2c_algorithm = {
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.functionality = sh_mobile_i2c_func,
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.master_xfer = sh_mobile_i2c_xfer,
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};
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static void sh_mobile_i2c_setup_channel(struct platform_device *dev)
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{
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struct sh_mobile_i2c_data *pd = platform_get_drvdata(dev);
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unsigned long peripheral_clk = clk_get_rate(pd->clk);
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u_int32_t num;
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u_int32_t denom;
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u_int32_t tmp;
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spin_lock_init(&pd->lock);
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init_waitqueue_head(&pd->wait);
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/* Calculate the value for iccl. From the data sheet:
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* iccl = (p clock / transfer rate) * (L / (L + H))
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* where L and H are the SCL low/high ratio (5/4 in this case).
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* We also round off the result.
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*/
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num = peripheral_clk * 5;
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denom = NORMAL_SPEED * 9;
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tmp = num * 10 / denom;
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if (tmp % 10 >= 5)
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pd->iccl = (u_int8_t)((num/denom) + 1);
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else
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pd->iccl = (u_int8_t)(num/denom);
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/* Calculate the value for icch. From the data sheet:
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icch = (p clock / transfer rate) * (H / (L + H)) */
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num = peripheral_clk * 4;
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tmp = num * 10 / denom;
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if (tmp % 10 >= 5)
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pd->icch = (u_int8_t)((num/denom) + 1);
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else
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pd->icch = (u_int8_t)(num/denom);
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}
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static int sh_mobile_i2c_hook_irqs(struct platform_device *dev, int hook)
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{
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struct resource *res;
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int ret = -ENXIO;
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int q, m;
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int k = 0;
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int n = 0;
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while ((res = platform_get_resource(dev, IORESOURCE_IRQ, k))) {
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for (n = res->start; hook && n <= res->end; n++) {
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if (request_irq(n, sh_mobile_i2c_isr, IRQF_DISABLED,
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dev->dev.bus_id, dev))
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goto rollback;
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}
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k++;
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}
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if (hook)
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return k > 0 ? 0 : -ENOENT;
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k--;
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ret = 0;
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rollback:
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for (q = k; k >= 0; k--) {
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for (m = n; m >= res->start; m--)
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free_irq(m, dev);
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res = platform_get_resource(dev, IORESOURCE_IRQ, k - 1);
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m = res->end;
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}
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return ret;
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}
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static int sh_mobile_i2c_probe(struct platform_device *dev)
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{
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struct sh_mobile_i2c_data *pd;
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struct i2c_adapter *adap;
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struct resource *res;
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int size;
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int ret;
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pd = kzalloc(sizeof(struct sh_mobile_i2c_data), GFP_KERNEL);
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if (pd == NULL) {
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dev_err(&dev->dev, "cannot allocate private data\n");
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return -ENOMEM;
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}
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pd->clk = clk_get(&dev->dev, "peripheral_clk");
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if (IS_ERR(pd->clk)) {
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dev_err(&dev->dev, "cannot get peripheral clock\n");
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ret = PTR_ERR(pd->clk);
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goto err;
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}
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ret = sh_mobile_i2c_hook_irqs(dev, 1);
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if (ret) {
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dev_err(&dev->dev, "cannot request IRQ\n");
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goto err_clk;
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}
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pd->dev = &dev->dev;
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platform_set_drvdata(dev, pd);
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res = platform_get_resource(dev, IORESOURCE_MEM, 0);
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if (res == NULL) {
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dev_err(&dev->dev, "cannot find IO resource\n");
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ret = -ENOENT;
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goto err_irq;
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}
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size = (res->end - res->start) + 1;
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pd->reg = ioremap(res->start, size);
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if (pd->reg == NULL) {
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dev_err(&dev->dev, "cannot map IO\n");
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ret = -ENXIO;
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goto err_irq;
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}
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/* setup the private data */
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adap = &pd->adap;
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i2c_set_adapdata(adap, pd);
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adap->owner = THIS_MODULE;
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adap->algo = &sh_mobile_i2c_algorithm;
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adap->dev.parent = &dev->dev;
|
||||
adap->retries = 5;
|
||||
adap->nr = dev->id;
|
||||
|
||||
strlcpy(adap->name, dev->name, sizeof(adap->name));
|
||||
|
||||
sh_mobile_i2c_setup_channel(dev);
|
||||
|
||||
ret = i2c_add_numbered_adapter(adap);
|
||||
if (ret < 0) {
|
||||
dev_err(&dev->dev, "cannot add numbered adapter\n");
|
||||
goto err_all;
|
||||
}
|
||||
|
||||
return 0;
|
||||
|
||||
err_all:
|
||||
iounmap(pd->reg);
|
||||
err_irq:
|
||||
sh_mobile_i2c_hook_irqs(dev, 0);
|
||||
err_clk:
|
||||
clk_put(pd->clk);
|
||||
err:
|
||||
kfree(pd);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int sh_mobile_i2c_remove(struct platform_device *dev)
|
||||
{
|
||||
struct sh_mobile_i2c_data *pd = platform_get_drvdata(dev);
|
||||
|
||||
i2c_del_adapter(&pd->adap);
|
||||
iounmap(pd->reg);
|
||||
sh_mobile_i2c_hook_irqs(dev, 0);
|
||||
clk_put(pd->clk);
|
||||
kfree(pd);
|
||||
return 0;
|
||||
}
|
||||
|
||||
static struct platform_driver sh_mobile_i2c_driver = {
|
||||
.driver = {
|
||||
.name = "i2c-sh_mobile",
|
||||
.owner = THIS_MODULE,
|
||||
},
|
||||
.probe = sh_mobile_i2c_probe,
|
||||
.remove = sh_mobile_i2c_remove,
|
||||
};
|
||||
|
||||
static int __init sh_mobile_i2c_adap_init(void)
|
||||
{
|
||||
return platform_driver_register(&sh_mobile_i2c_driver);
|
||||
}
|
||||
|
||||
static void __exit sh_mobile_i2c_adap_exit(void)
|
||||
{
|
||||
platform_driver_unregister(&sh_mobile_i2c_driver);
|
||||
}
|
||||
|
||||
module_init(sh_mobile_i2c_adap_init);
|
||||
module_exit(sh_mobile_i2c_adap_exit);
|
||||
|
||||
MODULE_DESCRIPTION("SuperH Mobile I2C Bus Controller driver");
|
||||
MODULE_AUTHOR("Magnus Damm");
|
||||
MODULE_LICENSE("GPL v2");
|
||||
Loading…
Reference in New Issue
Block a user