On Wed, Jul 25, 2012 at 12:06 PM, Kuninori Morimoto
<kuninori.morimoto.gx@xxxxxxxxxxx> wrote:
> R-Car I2C is similar with SH7760 I2C.
> But the SH7760 I2C driver had many workaround operations, since H/W had bugs.
> Thus, it was pointless to keep compatible between SH7760 and R-Car I2C drivers.
> This patch creates new Renesas R-Car I2C driver.
>
> Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>
> ---
> drivers/i2c/busses/Kconfig | 10 +
> drivers/i2c/busses/Makefile | 1 +
> drivers/i2c/busses/i2c-rcar.c | 741 +++++++++++++++++++++++++++++++++++++++++
> include/linux/i2c/i2c-rcar.h | 10 +
> 4 files changed, 762 insertions(+), 0 deletions(-)
> create mode 100644 drivers/i2c/busses/i2c-rcar.c
> create mode 100644 include/linux/i2c/i2c-rcar.h
>
> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> index 7244c8b..3175c81 100644
> --- a/drivers/i2c/busses/Kconfig
> +++ b/drivers/i2c/busses/Kconfig
> @@ -704,6 +704,16 @@ config I2C_XLR
> This driver can also be built as a module. If so, the module
> will be called i2c-xlr.
>
> +config I2C_RCAR
> + tristate "Renesas R-Car I2C Controller"
> + depends on ARCH_SHMOBILE && I2C
> + help
> + If you say yes to this option, support will be included for the
> + R-Car I2C controller.
> +
> + This driver can also be built as a module. If so, the module
> + will be called i2c-rcar.
> +
> comment "External I2C/SMBus adapter drivers"
>
> config I2C_DIOLAN_U2C
> diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
> index ce3c2be..e98ff51 100644
> --- a/drivers/i2c/busses/Makefile
> +++ b/drivers/i2c/busses/Makefile
> @@ -70,6 +70,7 @@ obj-$(CONFIG_I2C_VERSATILE) += i2c-versatile.o
> obj-$(CONFIG_I2C_OCTEON) += i2c-octeon.o
> obj-$(CONFIG_I2C_XILINX) += i2c-xiic.o
> obj-$(CONFIG_I2C_XLR) += i2c-xlr.o
> +obj-$(CONFIG_I2C_RCAR) += i2c-rcar.o
>
> # External I2C/SMBus adapter drivers
> obj-$(CONFIG_I2C_DIOLAN_U2C) += i2c-diolan-u2c.o
> diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
> new file mode 100644
> index 0000000..2993cab
> --- /dev/null
> +++ b/drivers/i2c/busses/i2c-rcar.c
> @@ -0,0 +1,741 @@
> +/*
> + * drivers/i2c/busses/i2c-rcar.c
> + *
> + * Copyright (C) 2012 Renesas Solutions Corp.
> + * Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>
> + *
> + * This file is based on the drivers/i2c/busses/i2c-sh7760.c
> + * (c) 2005-2008 MSC Vertriebsges.m.b.H, Manuel Lauss <mlau@xxxxxxxxxx>
> + *
> + * This file used out-of-tree driver i2c-rcar.c
> + * Copyright (C) 2011-2012 Renesas Electronics Corporation
> + *
> + * 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
> + *
> + * 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/clk.h>
> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/i2c.h>
> +#include <linux/i2c/i2c-rcar.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/slab.h>
> +#include <linux/spinlock.h>
> +
> +/* register offsets */
> +#define ICSCR 0x00 /* slave ctrl */
> +#define ICMCR 0x04 /* master ctrl */
> +#define ICSSR 0x08 /* slave status */
> +#define ICMSR 0x0C /* master status */
> +#define ICSIER 0x10 /* slave irq enable */
> +#define ICMIER 0x14 /* master irq enable */
> +#define ICCCR 0x18 /* clock dividers */
> +#define ICSAR 0x1C /* slave address */
> +#define ICMAR 0x20 /* master address */
> +#define ICRXTX 0x24 /* data port */
> +
> +/* ICMCR */
> +#define MDBS (1 << 7) /* non-fifo mode switch */
> +#define FSCL (1 << 6) /* override SCL pin */
> +#define FSDA (1 << 5) /* override SDA pin */
> +#define OBPC (1 << 4) /* override pins */
> +#define MIE (1 << 3) /* master if enable */
> +#define TSBE (1 << 2)
> +#define FSB (1 << 1) /* force stop bit */
> +#define ESG (1 << 0) /* en startbit gen */
> +
> +/* ICMSR */
> +#define MNR (1 << 6) /* nack received */
> +#define MAL (1 << 5) /* arbitration lost */
> +#define MST (1 << 4) /* sent a stop */
> +#define MDE (1 << 3)
> +#define MDT (1 << 2)
> +#define MDR (1 << 1)
> +#define MAT (1 << 0) /* slave addr xfer done */
> +
> +/* ICMIE */
> +#define MNRE (1 << 6) /* nack irq en */
> +#define MALE (1 << 5) /* arblos irq en */
> +#define MSTE (1 << 4) /* stop irq en */
> +#define MDEE (1 << 3)
> +#define MDTE (1 << 2)
> +#define MDRE (1 << 1)
> +#define MATE (1 << 0) /* address sent irq en */
> +
> +
> +enum {
> + RCAR_BUS_PHASE_ADDR,
> + RCAR_BUS_PHASE_DATA,
> + RCAR_BUS_PHASE_STOP,
> +};
> +
> +enum {
> + RCAR_IRQ_CLOSE,
> + RCAR_IRQ_OPEN_FOR_SEND,
> + RCAR_IRQ_OPEN_FOR_RECV,
> + RCAR_IRQ_OPEN_FOR_STOP,
> +};
> +
> +/*
> + * flags
> + */
> +#define ID_LAST_MSG (1 << 0)
> +#define ID_IOERROR (1 << 1)
> +#define ID_DONE (1 << 2)
> +#define ID_ARBLOST (1 << 3)
> +#define ID_NACK (1 << 4)
> +
> +struct rcar_i2c_priv {
> + void __iomem *io;
> + struct i2c_adapter adap;
> + struct i2c_msg *msg;
> +
> + spinlock_t lock;
> + wait_queue_head_t wait;
> +
> + int pos;
> + int irq;
> + u32 icccr;
> + u32 flags;
> +};
> +
> +#define rcar_i2c_priv_to_dev(p) ((p)->adap.dev.parent)
> +#define rcar_i2c_is_recv(p) ((p)->msg->flags & I2C_M_RD)
> +
> +#define rcar_i2c_flags_set(p, f) ((p)->flags |= (f))
> +#define rcar_i2c_flags_has(p, f) ((p)->flags & (f))
> +
> +/*
> + * basic functions
> + */
> +static void rcar_i2c_write(struct rcar_i2c_priv *priv, int reg, u32 val)
> +{
> + __raw_writel(val, priv->io + reg);
> +}
> +
> +static u32 rcar_i2c_read(struct rcar_i2c_priv *priv, int reg)
> +{
> + return __raw_readl(priv->io + reg);
> +}
> +
> +#if 0 /* no user at this point */
Could it be removed then?
BTW feel free to ignore such comments.
> +static u32 rcar_i2c_bset(struct rcar_i2c_priv *priv, int reg,
> + u32 mask, u32 data)
> +{
> + u32 val = rcar_i2c_read(priv, reg);
> +
> + val &= ~mask;
> + val |= (mask & data);
> +
> + rcar_i2c_write(priv, reg, val);
> +}
> +#endif
> +
> +static void rcar_i2c_soft_reset(struct rcar_i2c_priv *priv)
> +{
> + /*
> + * reset slave mode.
> + * slave mode is not used on this driver
> + */
> + rcar_i2c_write(priv, ICSIER, 0);
> + rcar_i2c_write(priv, ICSAR, 0);
> + rcar_i2c_write(priv, ICSCR, 0);
> + rcar_i2c_write(priv, ICSSR, 0);
> +
> + /* reset master mode */
> + rcar_i2c_write(priv, ICMIER, 0);
> + rcar_i2c_write(priv, ICMCR, 0);
> + rcar_i2c_write(priv, ICMSR, 0);
> + rcar_i2c_write(priv, ICMAR, 0);
> +}
> +
> +static void rcar_i2c_irq_mask(struct rcar_i2c_priv *priv, int open)
> +{
> + u32 val = MNRE | MALE | MSTE | MATE; /* default */
> +
> + switch (open) {
> + case RCAR_IRQ_OPEN_FOR_SEND:
> + val |= MDEE; /* default + send */
> + break;
> + case RCAR_IRQ_OPEN_FOR_RECV:
> + val |= MDRE; /* default + read */
> + break;
> + case RCAR_IRQ_OPEN_FOR_STOP:
> + val = MSTE; /* stop irq only */
> + break;
> + case RCAR_IRQ_CLOSE:
> + default:
> + val = 0; /* all close */
> + break;
> + }
> + rcar_i2c_write(priv, ICMIER, val);
> +}
> +
> +static void rcar_i2c_set_addr(struct rcar_i2c_priv *priv, u32 recv)
> +{
> + rcar_i2c_write(priv, ICMAR, (priv->msg->addr << 1) | recv);
> +}
> +
> +/*
> + * bus control functions
> + */
> +static int rcar_i2c_bus_barrier(struct rcar_i2c_priv *priv)
> +{
> + int i;
> +
> + for (i = 0; i < 1024; i++) {
> + if (!(rcar_i2c_read(priv, ICMCR) & FSDA))
Did not understand this would be grateful if you could explain.
> + return 0;
> + udelay(1);
> + }
> +
> + return -EBUSY;
> +}
> +
> +static void rcar_i2c_bus_phase(struct rcar_i2c_priv *priv, int phase)
> +{
> + switch (phase) {
> + case RCAR_BUS_PHASE_ADDR:
> + rcar_i2c_write(priv, ICMCR, MDBS | MIE | ESG);
> + break;
> + case RCAR_BUS_PHASE_DATA:
> + rcar_i2c_write(priv, ICMCR, MDBS | MIE);
> + break;
> + case RCAR_BUS_PHASE_STOP:
> + rcar_i2c_write(priv, ICMCR, MDBS | MIE | FSB);
> + break;
> + }
> +
> + return;
> +}
> +
> +/*
> + * clock function
> + */
> +static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv,
> + u32 bus_speed,
> + struct device *dev)
> +{
> + struct clk *clkp = clk_get(NULL, "peripheral_clk");
> + u32 scgd, cdf;
> + u32 round, ick;
> +
> + if (!clkp) {
> + dev_err(dev, "there is no peripheral_clk\n");
> + return -EIO;
> + }
> +
> + /*
> + * use 95% bus speed for safety.
> + */
> + bus_speed = bus_speed * 95 / 100;
> +
> + /*
> + * calculate SCL clock
> + * see
> + * ICCCR
> + *
> + * ick = clkp / (1 + CDF)
> + * SCL = ick / (20 + SCGD * 8 + F[(ticf + tr + intd) * ick])
> + *
> + * ick : I2C internal clock < 20 MHz
> + * ticf : I2C SCL falling time = 35 ns here
> + * tr : I2C SCL rising time = 200 ns here
> + * intd : LSI internal delay = 50 ns here
> + * clkp : peripheral_clk
> + * F[] : integer up-valuation
> + */
> + for (cdf = 0; cdf < 4; cdf++) {
> + ick = clk_get_rate(clkp) / (1 + cdf);
> + if (ick < 20000000)
> + goto ick_find;
> + }
> + dev_err(dev, "there is no best CDF\n");
> +
> + return -EIO;
> +
> +ick_find:
> + /*
> + * it is impossible to calculate large scale
> + * number on u32
> + *
> + * F[(ticf + tr + intd) * ick]
> + * = F[(35 + 200 + 50)ns * ick]
> + * = F[285 * ick / 1000000000]
> + * = F[(ick / 1000000) * 285 / 1000]
> + */
> + round = (ick + 500000) / 1000000 * 285;
> + round = (round + 500) / 1000;
> +
> + /*
> + * SCL = ick / (20 + SCGD * 8 + F[(ticf + tr + intd) * ick])
> + * -> (20 + SCGD * 8 + round) = ick / SCL
> + * -> SCGD * 8 = (ick / SCL) - 20 - round
> + * -> SCGD = F[((ick / SCL) - 20 - round) / 8]
> + * -> SCGD = ((ick / SCL) - 20 - round + 4) / 8
> + */
> + scgd = ((ick / bus_speed) - 20 - round + 4) / 8;
> +
> + dev_dbg(dev, "clk %u(%lu), round %u, SCL %d, CDF:0x%x, SCGD: 0x%x\n",
> + ick / (20 + scgd * 8 + round),
> + clk_get_rate(clkp), round, bus_speed, cdf, scgd);
> +
> + /*
> + * keep icccr value
> + */
> + priv->icccr = (scgd << 2 | cdf);
> +
> + return 0;
> +}
> +
> +static void rcar_i2c_clock_start(struct rcar_i2c_priv *priv)
> +{
> + rcar_i2c_write(priv, ICCCR, priv->icccr);
> +}
> +
> +/*
> + * status functions
> + */
> +static u32 rcar_i2c_status_get(struct rcar_i2c_priv *priv)
> +{
> + return rcar_i2c_read(priv, ICMSR);
> +}
> +
> +#define rcar_i2c_status_clear(priv) rcar_i2c_status_bit_clear(priv, 0xffffffff)
> +static void rcar_i2c_status_bit_clear(struct rcar_i2c_priv *priv, u32 bit)
> +{
> + rcar_i2c_write(priv, ICMSR, ~bit);
> +}
> +
> +/*
> + * recv/send functions
> + */
> +static int rcar_i2c_recv(struct rcar_i2c_priv *priv)
> +{
> + rcar_i2c_set_addr(priv, 1);
> + rcar_i2c_status_clear(priv);
> + rcar_i2c_bus_phase(priv, RCAR_BUS_PHASE_ADDR);
> + rcar_i2c_irq_mask(priv, RCAR_IRQ_OPEN_FOR_RECV);
> +
> + return 0;
> +}
> +
> +static int rcar_i2c_send(struct rcar_i2c_priv *priv)
> +{
> + int ret;
> +
> + /*
> + * It should check bus status when send case
> + */
> + ret = rcar_i2c_bus_barrier(priv);
> + if (ret < 0)
> + return ret;
> +
> + rcar_i2c_set_addr(priv, 0);
> + rcar_i2c_status_clear(priv);
> + rcar_i2c_bus_phase(priv, RCAR_BUS_PHASE_ADDR);
> + rcar_i2c_irq_mask(priv, RCAR_IRQ_OPEN_FOR_SEND);
> +
> + return 0;
> +}
> +
> +#define rcar_i2c_send_restart(priv) rcar_i2c_status_bit_clear(priv, (MAT | MDE))
> +#define rcar_i2c_recv_restart(priv) rcar_i2c_status_bit_clear(priv, (MAT | MDR))
> +
> +/*
> + * interrupt functions
> + */
> +static int rcar_i2c_irq_send(struct rcar_i2c_priv *priv, u32 msr)
> +{
> + struct i2c_msg *msg = priv->msg;
> +
> + /*
> + * FIXME
> + * sometimes, unknown interrupt happend.
> + * Do nothing
> + */
> + if (!(msr & MDE))
> + return 0;
> +
> + /*
> + * If address transfer phase finised,
> + * goto data phase.
> + */
> + if (msr & MAT)
> + rcar_i2c_bus_phase(priv, RCAR_BUS_PHASE_DATA);
> +
> + if (priv->pos < msg->len) {
> + /*
> + * Prepare next data to ICRXTX register.
> + * This data will go to _SHIFT_ register.
> + *
> + * *
> + * [ICRXTX] -> [SHIFT] -> [I2C bus]
> + */
> + rcar_i2c_write(priv, ICRXTX, msg->buf[priv->pos]);
> + priv->pos++;
> +
> + } else {
> + /*
> + * The last data was pushed to ICRXTX on _PREV_ empty irq.
> + * It is on _SHIFT_ register, and will sent to I2C bus.
> + *
> + * *
> + * [ICRXTX] -> [SHIFT] -> [I2C bus]
> + */
> +
> + if (priv->flags & ID_LAST_MSG)
> + /*
> + * If current msg is the _LAST_ msg,
> + * prepare stop condition here.
> + * ID_DONE will be set on STOP irq.
> + */
> + rcar_i2c_bus_phase(priv, RCAR_BUS_PHASE_STOP);
> + else
> + /*
> + * If current msg is _NOT_ last msg,
> + * it doesn't call stop phase.
> + * thus, there is no STOP irq.
> + * return ID_DONE here.
> + */
> + return ID_DONE;
> + }
> +
> + rcar_i2c_send_restart(priv);
> +
> + return 0;
> +}
> +
> +static int rcar_i2c_irq_recv(struct rcar_i2c_priv *priv, u32 msr)
> +{
> + struct i2c_msg *msg = priv->msg;
> +
> + /*
> + * FIXME
> + * sometimes, unknown interrupt happend.
> + * Do nothing
> + */
> + if (!(msr & MDR))
> + return 0;
> +
> + if (msr & MAT) {
> + /*
> + * Address transfer phase finished,
> + * but, there is no data at this point.
> + * Do nothing.
> + */
> + } else if (priv->pos < msg->len) {
> + /*
> + * get received data
> + */
> + msg->buf[priv->pos] = rcar_i2c_read(priv, ICRXTX);
> + priv->pos++;
> + }
> +
> + /*
> + * If next received data is the last data,
> + * I2C driver should send NACK (or STOP).
> + * But this chip can't send NACK, thus, go to STOP phase.
> + * Otherwise, go to data phase.
> + */
> + if (priv->pos + 1 >= msg->len)
> + rcar_i2c_bus_phase(priv, RCAR_BUS_PHASE_STOP);
> + else
> + rcar_i2c_bus_phase(priv, RCAR_BUS_PHASE_DATA);
> +
> + rcar_i2c_recv_restart(priv);
> +
> + return 0;
> +}
> +
> +static irqreturn_t rcar_i2c_irq(int irq, void *ptr)
> +{
> + struct rcar_i2c_priv *priv = ptr;
> + struct device *dev = rcar_i2c_priv_to_dev(priv);
> + u32 msr;
> +
> + /*-------------- spin lock -----------------*/
> + spin_lock(&priv->lock);
> +
> + msr = rcar_i2c_status_get(priv);
> +
> + /*
> + * Arbitration lost
> + */
> + if (msr & MAL) {
> + /*
> + * CAUTION
> + *
> + * When arbitration lost, device become _slave_ mode.
> + */
> + dev_dbg(dev, "Arbitration Lost\n");
> + rcar_i2c_flags_set(priv, (ID_DONE | ID_ARBLOST));
> + goto out;
> + }
> +
> + /*
> + * Stop
> + */
> + if (msr & MST) {
> + dev_dbg(dev, "Stop\n");
> + rcar_i2c_flags_set(priv, ID_DONE);
> + goto out;
> + }
> +
> + /*
> + * Nack
> + */
> + if (msr & MNR) {
> + dev_dbg(dev, "Nack\n");
> +
> + /* go to stop phase */
> + rcar_i2c_bus_phase(priv, RCAR_BUS_PHASE_STOP);
> + rcar_i2c_irq_mask(priv, RCAR_IRQ_OPEN_FOR_STOP);
stop is sent regardless of IGNORE nak? Do you think it would be an issue?
> + rcar_i2c_flags_set(priv, ID_NACK);
> + goto out;
> + }
> +
> + /*
> + * recv/send
> + */
> + if (rcar_i2c_is_recv(priv))
> + rcar_i2c_flags_set(priv, rcar_i2c_irq_recv(priv, msr));
> + else
> + rcar_i2c_flags_set(priv, rcar_i2c_irq_send(priv, msr));
> +
> +out:
> + if (rcar_i2c_flags_has(priv, ID_DONE)) {
> + rcar_i2c_irq_mask(priv, RCAR_IRQ_CLOSE);
> + rcar_i2c_status_clear(priv);
> + wake_up(&priv->wait);
> + }
> +
> + spin_unlock(&priv->lock);
> + /*-------------- spin unlock -----------------*/
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
> + struct i2c_msg *msgs,
> + int num)
> +{
> + struct rcar_i2c_priv *priv = i2c_get_adapdata(adap);
> + struct device *dev = rcar_i2c_priv_to_dev(priv);
> + unsigned long flags;
> + int i, ret, timeout;
> +
> + /*================== enable i2c device ===================*/
> + pm_runtime_get_sync(dev);
> +
> + /*-------------- spin lock -----------------*/
> + spin_lock_irqsave(&priv->lock, flags);
> +
> + rcar_i2c_soft_reset(priv);
could you explain this.
> + rcar_i2c_clock_start(priv);
> +
> + spin_unlock_irqrestore(&priv->lock, flags);
> + /*-------------- spin unlock -----------------*/
> +
> + ret = -EINVAL;
> + for (i = 0; i < num; i++) {
> + /*-------------- spin lock -----------------*/
> + spin_lock_irqsave(&priv->lock, flags);
> +
> + /* init each data */
> + priv->msg = &msgs[i];
> + priv->pos = 0;
> + priv->flags = 0;
> + if (priv->msg == &msgs[num - 1])
> + rcar_i2c_flags_set(priv, ID_LAST_MSG);
> +
> + /* start send/recv */
> + if (rcar_i2c_is_recv(priv))
> + ret = rcar_i2c_recv(priv);
> + else
> + ret = rcar_i2c_send(priv);
> +
> + spin_unlock_irqrestore(&priv->lock, flags);
> + /*-------------- spin unlock -----------------*/
> +
> + if (ret < 0)
> + break;
> +
> + /*
> + * wait result
> + */
> + timeout = wait_event_timeout(priv->wait,
> + rcar_i2c_flags_has(priv, ID_DONE),
> + 5 * HZ);
> + if (!timeout) {
> + ret = -ETIMEDOUT;
> + break;
> + }
> +
> + /*
> + * error handling
> + */
> + if (rcar_i2c_flags_has(priv, ID_NACK)) {
> + ret = -EREMOTEIO;
> +
> + if (msgs->flags & I2C_M_IGNORE_NAK)
you have the IGNORE_NAK support should we update the func flags then(magling)?
> + ret = 0;
> + break;
> + }
> +
> + if (rcar_i2c_flags_has(priv, ID_ARBLOST)) {
> + ret = -EAGAIN;
> + break;
> + }
> +
> + if (rcar_i2c_flags_has(priv, ID_IOERROR)) {
> + ret = -EIO;
> + break;
> + }
> +
> + ret = i + 1; /* The number of transfer */
> + }
> +
> + pm_runtime_put_sync(dev);
> + /*================== disable i2c device ===================*/
> +
> + if (ret < 0)
> + dev_err(dev, "error %d : %x\n", ret, priv->flags);
> +
> + return ret;
> +}
> +
> +static u32 rcar_i2c_func(struct i2c_adapter *adap)
> +{
> + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
> +}
> +
> +static const struct i2c_algorithm rcar_i2c_algo = {
> + .master_xfer = rcar_i2c_master_xfer,
> + .functionality = rcar_i2c_func,
> +};
> +
> +static int __devinit rcar_i2c_probe(struct platform_device *pdev)
> +{
> + struct i2c_rcar_platform_data *pdata = pdev->dev.platform_data;
> + struct rcar_i2c_priv *priv;
> + struct i2c_adapter *adap;
> + struct resource *res;
> + struct device *dev = &pdev->dev;
> + u32 bus_speed;
> + int ret;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res) {
> + dev_err(dev, "no mmio resources\n");
> + return -ENODEV;
> + }
> +
> + priv = devm_kzalloc(dev, sizeof(struct rcar_i2c_priv), GFP_KERNEL);
> + if (!priv) {
> + dev_err(dev, "no mem for private data\n");
> + return -ENOMEM;
> + }
> +
> + bus_speed = 100000; /* default 100 kHz */
> + if (pdata && pdata->bus_speed)
> + bus_speed = pdata->bus_speed;
> + ret = rcar_i2c_clock_calculate(priv, bus_speed, dev);
> + if (ret < 0)
> + goto error_free;
> +
> + priv->io = devm_ioremap(dev, res->start, resource_size(res));
> + if (!priv->io) {
> + dev_err(dev, "cannot ioremap\n");
> + ret = -ENODEV;
> + goto error_free;
> + }
> +
> + priv->irq = platform_get_irq(pdev, 0);
> + init_waitqueue_head(&priv->wait);
> + spin_lock_init(&priv->lock);
> +
> + adap = &priv->adap;
> + adap->nr = pdev->id;
> + adap->algo = &rcar_i2c_algo;
> + adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
> + adap->retries = 3;
There was a discurssion about the retries being the responsibility of
the driver.
Not sure though.
> + adap->dev.parent = dev;
> + i2c_set_adapdata(adap, priv);
> + strlcpy(adap->name, pdev->name, sizeof(adap->name));
> +
> + if (request_irq(priv->irq, rcar_i2c_irq, 0,
> + dev_name(dev), priv)) {
> + dev_err(dev, "cannot get irq %d\n", priv->irq);
> + ret = -EBUSY;
> + goto error_unmap;
> + }
> +
> + ret = i2c_add_numbered_adapter(adap);
> + if (ret < 0) {
> + dev_err(dev, "reg adap failed: %d\n", ret);
> + goto error_irq;
> + }
> +
> + pm_runtime_enable(dev);
> + platform_set_drvdata(pdev, priv);
> +
> + dev_info(dev, "probed\n");
> +
> + return 0;
> +
> +error_irq:
> + free_irq(priv->irq, priv);
> +error_unmap:
> + devm_iounmap(dev, priv->io);
> +error_free:
> + devm_kfree(dev, priv);
why not let dev res handle these.
> +
> + return ret;
> +}
> +
> +static int __devexit rcar_i2c_remove(struct platform_device *pdev)
> +{
> + struct rcar_i2c_priv *priv = platform_get_drvdata(pdev);
> + struct device *dev = &pdev->dev;
> +
> + i2c_del_adapter(&priv->adap);
> + free_irq(priv->irq, priv);
> + devm_iounmap(dev, priv->io);
> + devm_kfree(dev, priv);
these may not be needed.
> + platform_set_drvdata(pdev, NULL);
not sure if this is needed.
> + pm_runtime_disable(dev);
> +
> + return 0;
> +}
> +
> +static struct platform_driver rcar_i2c_drv = {
> + .driver = {
> + .name = "i2c-rcar",
> + .owner = THIS_MODULE,
> + },
> + .probe = rcar_i2c_probe,
> + .remove = __devexit_p(rcar_i2c_remove),
> +};
> +
> +module_platform_driver(rcar_i2c_drv);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("Renesas R-Car I2C bus driver");
> +MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>");
> diff --git a/include/linux/i2c/i2c-rcar.h b/include/linux/i2c/i2c-rcar.h
> new file mode 100644
> index 0000000..496f5c2
> --- /dev/null
> +++ b/include/linux/i2c/i2c-rcar.h
> @@ -0,0 +1,10 @@
> +#ifndef __I2C_R_CAR_H__
> +#define __I2C_R_CAR_H__
> +
> +#include <linux/platform_device.h>
> +
> +struct i2c_rcar_platform_data {
> + u32 bus_speed;
> +};
> +
> +#endif /* __I2C_R_CAR_H__ */
> --
> 1.7.5.4
>
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