diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-rcar.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-rcar.c | 259 |
1 files changed, 52 insertions, 207 deletions
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c index 06d47aafbb79..899405923678 100644 --- a/drivers/i2c/busses/i2c-rcar.c +++ b/drivers/i2c/busses/i2c-rcar.c @@ -1,7 +1,9 @@ /* - * drivers/i2c/busses/i2c-rcar.c + * Driver for the Renesas RCar I2C unit * - * Copyright (C) 2012 Renesas Solutions Corp. + * Copyright (C) 2014 Wolfram Sang <wsa@sang-engineering.com> + * + * Copyright (C) 2012-14 Renesas Solutions Corp. * Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> * * This file is based on the drivers/i2c/busses/i2c-sh7760.c @@ -12,16 +14,12 @@ * * 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 + * the Free Software Foundation; 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> @@ -36,7 +34,6 @@ #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 */ @@ -60,7 +57,7 @@ #define FSB (1 << 1) /* force stop bit */ #define ESG (1 << 0) /* en startbit gen */ -/* ICMSR */ +/* ICMSR (also for ICMIE) */ #define MNR (1 << 6) /* nack received */ #define MAL (1 << 5) /* arbitration lost */ #define MST (1 << 4) /* sent a stop */ @@ -69,32 +66,18 @@ #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 */ +#define RCAR_BUS_PHASE_START (MDBS | MIE | ESG) +#define RCAR_BUS_PHASE_DATA (MDBS | MIE) +#define RCAR_BUS_PHASE_STOP (MDBS | MIE | FSB) -enum { - RCAR_BUS_PHASE_ADDR, - RCAR_BUS_PHASE_DATA, - RCAR_BUS_PHASE_STOP, -}; +#define RCAR_IRQ_SEND (MNR | MAL | MST | MAT | MDE) +#define RCAR_IRQ_RECV (MNR | MAL | MST | MAT | MDR) +#define RCAR_IRQ_STOP (MST) -enum { - RCAR_IRQ_CLOSE, - RCAR_IRQ_OPEN_FOR_SEND, - RCAR_IRQ_OPEN_FOR_RECV, - RCAR_IRQ_OPEN_FOR_STOP, -}; +#define RCAR_IRQ_ACK_SEND (~(MAT | MDE)) +#define RCAR_IRQ_ACK_RECV (~(MAT | MDR)) -/* - * flags - */ #define ID_LAST_MSG (1 << 0) #define ID_IOERROR (1 << 1) #define ID_DONE (1 << 2) @@ -112,14 +95,12 @@ struct rcar_i2c_priv { struct i2c_msg *msg; struct clk *clk; - spinlock_t lock; wait_queue_head_t wait; int pos; - int irq; u32 icccr; u32 flags; - enum rcar_i2c_type devtype; + enum rcar_i2c_type devtype; }; #define rcar_i2c_priv_to_dev(p) ((p)->adap.dev.parent) @@ -130,9 +111,7 @@ struct rcar_i2c_priv { #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); @@ -161,36 +140,6 @@ static void rcar_i2c_init(struct rcar_i2c_priv *priv) 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; @@ -205,24 +154,6 @@ static int rcar_i2c_bus_barrier(struct rcar_i2c_priv *priv) 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) @@ -312,60 +243,18 @@ scgd_find: 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) +static int rcar_i2c_prepare_msg(struct rcar_i2c_priv *priv) { - int ret; + int read = !!rcar_i2c_is_recv(priv); - /* - * 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); + rcar_i2c_write(priv, ICMAR, (priv->msg->addr << 1) | read); + rcar_i2c_write(priv, ICMSR, 0); + rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_START); + rcar_i2c_write(priv, ICMIER, read ? RCAR_IRQ_RECV : RCAR_IRQ_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 */ @@ -386,7 +275,7 @@ static int rcar_i2c_irq_send(struct rcar_i2c_priv *priv, u32 msr) * goto data phase. */ if (msr & MAT) - rcar_i2c_bus_phase(priv, RCAR_BUS_PHASE_DATA); + rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_DATA); if (priv->pos < msg->len) { /* @@ -414,7 +303,7 @@ static int rcar_i2c_irq_send(struct rcar_i2c_priv *priv, u32 msr) * prepare stop condition here. * ID_DONE will be set on STOP irq. */ - rcar_i2c_bus_phase(priv, RCAR_BUS_PHASE_STOP); + rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP); else /* * If current msg is _NOT_ last msg, @@ -425,7 +314,7 @@ static int rcar_i2c_irq_send(struct rcar_i2c_priv *priv, u32 msr) return ID_DONE; } - rcar_i2c_send_restart(priv); + rcar_i2c_write(priv, ICMSR, RCAR_IRQ_ACK_SEND); return 0; } @@ -462,11 +351,11 @@ static int rcar_i2c_irq_recv(struct rcar_i2c_priv *priv, u32 msr) * otherwise, go to DATA phase. */ if (priv->pos + 1 >= msg->len) - rcar_i2c_bus_phase(priv, RCAR_BUS_PHASE_STOP); + rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP); else - rcar_i2c_bus_phase(priv, RCAR_BUS_PHASE_DATA); + rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_DATA); - rcar_i2c_recv_restart(priv); + rcar_i2c_write(priv, ICMSR, RCAR_IRQ_ACK_RECV); return 0; } @@ -474,53 +363,31 @@ static int rcar_i2c_irq_recv(struct rcar_i2c_priv *priv, u32 msr) 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); + msr = rcar_i2c_read(priv, ICMSR); - /* - * Arbitration lost - */ + /* 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 - */ + /* Stop */ if (msr & MST) { - dev_dbg(dev, "Stop\n"); rcar_i2c_flags_set(priv, ID_DONE); goto out; } - /* - * Nack - */ + /* 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_write(priv, ICMCR, RCAR_BUS_PHASE_STOP); + rcar_i2c_write(priv, ICMIER, RCAR_IRQ_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 @@ -528,14 +395,11 @@ static irqreturn_t rcar_i2c_irq(int irq, void *ptr) out: if (rcar_i2c_flags_has(priv, ID_DONE)) { - rcar_i2c_irq_mask(priv, RCAR_IRQ_CLOSE); - rcar_i2c_status_clear(priv); + rcar_i2c_write(priv, ICMIER, 0); + rcar_i2c_write(priv, ICMSR, 0); wake_up(&priv->wait); } - spin_unlock(&priv->lock); - /*-------------- spin unlock -----------------*/ - return IRQ_HANDLED; } @@ -545,21 +409,18 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap, { 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); + /* start clock */ + rcar_i2c_write(priv, ICCCR, priv->icccr); - spin_unlock_irqrestore(&priv->lock, flags); - /*-------------- spin unlock -----------------*/ + ret = rcar_i2c_bus_barrier(priv); + if (ret < 0) + goto out; - ret = -EINVAL; for (i = 0; i < num; i++) { /* This HW can't send STOP after address phase */ if (msgs[i].len == 0) { @@ -567,9 +428,6 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap, break; } - /*-------------- spin lock -----------------*/ - spin_lock_irqsave(&priv->lock, flags); - /* init each data */ priv->msg = &msgs[i]; priv->pos = 0; @@ -577,21 +435,11 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap, 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 -----------------*/ + ret = rcar_i2c_prepare_msg(priv); if (ret < 0) break; - /* - * wait result - */ timeout = wait_event_timeout(priv->wait, rcar_i2c_flags_has(priv, ID_DONE), 5 * HZ); @@ -600,9 +448,6 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap, break; } - /* - * error handling - */ if (rcar_i2c_flags_has(priv, ID_NACK)) { ret = -ENXIO; break; @@ -620,7 +465,7 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap, ret = i + 1; /* The number of transfer */ } - +out: pm_runtime_put(dev); if (ret < 0 && ret != -ENXIO) @@ -646,6 +491,9 @@ static const struct of_device_id rcar_i2c_dt_ids[] = { { .compatible = "renesas,i2c-r8a7779", .data = (void *)I2C_RCAR_GEN1 }, { .compatible = "renesas,i2c-r8a7790", .data = (void *)I2C_RCAR_GEN2 }, { .compatible = "renesas,i2c-r8a7791", .data = (void *)I2C_RCAR_GEN2 }, + { .compatible = "renesas,i2c-r8a7792", .data = (void *)I2C_RCAR_GEN2 }, + { .compatible = "renesas,i2c-r8a7793", .data = (void *)I2C_RCAR_GEN2 }, + { .compatible = "renesas,i2c-r8a7794", .data = (void *)I2C_RCAR_GEN2 }, {}, }; MODULE_DEVICE_TABLE(of, rcar_i2c_dt_ids); @@ -658,13 +506,11 @@ static int rcar_i2c_probe(struct platform_device *pdev) struct resource *res; struct device *dev = &pdev->dev; u32 bus_speed; - int ret; + int irq, ret; priv = devm_kzalloc(dev, sizeof(struct rcar_i2c_priv), GFP_KERNEL); - if (!priv) { - dev_err(dev, "no mem for private data\n"); + if (!priv) return -ENOMEM; - } priv->clk = devm_clk_get(dev, NULL); if (IS_ERR(priv->clk)) { @@ -692,9 +538,8 @@ static int rcar_i2c_probe(struct platform_device *pdev) if (IS_ERR(priv->io)) return PTR_ERR(priv->io); - priv->irq = platform_get_irq(pdev, 0); + irq = platform_get_irq(pdev, 0); init_waitqueue_head(&priv->wait); - spin_lock_init(&priv->lock); adap = &priv->adap; adap->nr = pdev->id; @@ -706,10 +551,10 @@ static int rcar_i2c_probe(struct platform_device *pdev) i2c_set_adapdata(adap, priv); strlcpy(adap->name, pdev->name, sizeof(adap->name)); - ret = devm_request_irq(dev, priv->irq, rcar_i2c_irq, 0, + ret = devm_request_irq(dev, irq, rcar_i2c_irq, 0, dev_name(dev), priv); if (ret < 0) { - dev_err(dev, "cannot get irq %d\n", priv->irq); + dev_err(dev, "cannot get irq %d\n", irq); return ret; } @@ -759,6 +604,6 @@ static struct platform_driver rcar_i2c_driver = { module_platform_driver(rcar_i2c_driver); -MODULE_LICENSE("GPL"); +MODULE_LICENSE("GPL v2"); MODULE_DESCRIPTION("Renesas R-Car I2C bus driver"); MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>"); |