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Diffstat (limited to 'drivers/i2c/busses/i2c-rcar.c')
-rw-r--r--drivers/i2c/busses/i2c-rcar.c259
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>");
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-10 11:00:08 +0100