diff options
| -rw-r--r-- | drivers/i2c/busses/Kconfig | 10 | ||||
| -rw-r--r-- | drivers/i2c/busses/Makefile | 1 | ||||
| -rw-r--r-- | drivers/i2c/busses/i2c-rcar.c | 709 | ||||
| -rw-r--r-- | include/linux/i2c/i2c-rcar.h | 10 |
4 files changed, 730 insertions, 0 deletions
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index da77c37caf1..c8c11b21778 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -712,6 +712,16 @@ 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 ce3c2be7fb4..e98ff51e9d9 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 00000000000..f9399d163af --- /dev/null +++ b/drivers/i2c/busses/i2c-rcar.c @@ -0,0 +1,709 @@ +/* + * drivers/i2c/busses/i2c-rcar.c + * + * Copyright (C) 2012 Renesas Solutions Corp. + * Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> + * + * This file is based on the drivers/i2c/busses/i2c-sh7760.c + * (c) 2005-2008 MSC Vertriebsges.m.b.H, Manuel Lauss <mlau@msc-ge.com> + * + * 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)) + +#define LOOP_TIMEOUT 1024 + +/* + * basic functions + */ +static void rcar_i2c_write(struct rcar_i2c_priv *priv, int reg, u32 val) +{ + writel(val, priv->io + reg); +} + +static u32 rcar_i2c_read(struct rcar_i2c_priv *priv, int reg) +{ + return readl(priv->io + reg); +} + +static void rcar_i2c_init(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 < LOOP_TIMEOUT; i++) { + /* make sure that bus is not busy */ + if (!(rcar_i2c_read(priv, ICMCR) & FSDA)) + 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; + } +} + +/* + * 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; + u32 scl; + + if (!clkp) { + dev_err(dev, "there is no peripheral_clk\n"); + return -EIO; + } + + /* + * 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. separate it + * + * 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]) + * + * Calculation result (= SCL) should be less than + * bus_speed for hardware safety + */ + for (scgd = 0; scgd < 0x40; scgd++) { + scl = ick / (20 + (scgd * 8) + round); + if (scl <= bus_speed) + goto scgd_find; + } + dev_err(dev, "it is impossible to calculate best SCL\n"); + return -EIO; + +scgd_find: + dev_dbg(dev, "clk %d/%d(%lu), round %u, CDF:0x%x, SCGD: 0x%x\n", + scl, bus_speed, clk_get_rate(clkp), round, 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 happened. + * Do nothing + */ + if (!(msr & MDE)) + return 0; + + /* + * If address transfer phase finished, + * 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 happened. + * 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_, + * 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); + 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; + + pm_runtime_get_sync(dev); + + /*-------------- spin lock -----------------*/ + spin_lock_irqsave(&priv->lock, flags); + + rcar_i2c_init(priv); + 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; + 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(dev); + + 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) + return ret; + + priv->io = devm_ioremap(dev, res->start, resource_size(res)); + if (!priv->io) { + dev_err(dev, "cannot ioremap\n"); + return -ENODEV; + } + + 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; + adap->dev.parent = dev; + i2c_set_adapdata(adap, priv); + strlcpy(adap->name, pdev->name, sizeof(adap->name)); + + ret = devm_request_irq(dev, priv->irq, rcar_i2c_irq, 0, + dev_name(dev), priv); + if (ret < 0) { + dev_err(dev, "cannot get irq %d\n", priv->irq); + return ret; + } + + ret = i2c_add_numbered_adapter(adap); + if (ret < 0) { + dev_err(dev, "reg adap failed: %d\n", ret); + return ret; + } + + pm_runtime_enable(dev); + platform_set_drvdata(pdev, priv); + + dev_info(dev, "probed\n"); + + return 0; +} + +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); + 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@renesas.com>"); diff --git a/include/linux/i2c/i2c-rcar.h b/include/linux/i2c/i2c-rcar.h new file mode 100644 index 00000000000..496f5c2b23c --- /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__ */ |