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path: root/drivers/i2c/busses/i2c-altera.c
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Diffstat (limited to 'drivers/i2c/busses/i2c-altera.c')
-rw-r--r--drivers/i2c/busses/i2c-altera.c79
1 files changed, 32 insertions, 47 deletions
diff --git a/drivers/i2c/busses/i2c-altera.c b/drivers/i2c/busses/i2c-altera.c
index f5e1941e65b5..2da73173ce24 100644
--- a/drivers/i2c/busses/i2c-altera.c
+++ b/drivers/i2c/busses/i2c-altera.c
@@ -1,18 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright Intel Corporation (C) 2017.
*
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
- *
* Based on the i2c-axxia.c driver.
*/
#include <linux/clk.h>
@@ -66,7 +55,7 @@
#define ALTR_I2C_XFER_TIMEOUT (msecs_to_jiffies(250))
/**
- * altr_i2c_dev - I2C device context
+ * struct altr_i2c_dev - I2C device context
* @base: pointer to register struct
* @msg: pointer to current message
* @msg_len: number of bytes transferred in msg
@@ -80,7 +69,7 @@
* @fifo_size: size of the FIFO passed in.
* @isr_mask: cached copy of local ISR enables.
* @isr_status: cached copy of local ISR status.
- * @lock: spinlock for IRQ synchronization.
+ * @isr_mutex: mutex for IRQ thread.
*/
struct altr_i2c_dev {
void __iomem *base;
@@ -96,17 +85,14 @@ struct altr_i2c_dev {
u32 fifo_size;
u32 isr_mask;
u32 isr_status;
- spinlock_t lock; /* IRQ synchronization */
+ struct mutex isr_mutex;
};
static void
altr_i2c_int_enable(struct altr_i2c_dev *idev, u32 mask, bool enable)
{
- unsigned long flags;
u32 int_en;
- spin_lock_irqsave(&idev->lock, flags);
-
int_en = readl(idev->base + ALTR_I2C_ISER);
if (enable)
idev->isr_mask = int_en | mask;
@@ -114,8 +100,6 @@ altr_i2c_int_enable(struct altr_i2c_dev *idev, u32 mask, bool enable)
idev->isr_mask = int_en & ~mask;
writel(idev->isr_mask, idev->base + ALTR_I2C_ISER);
-
- spin_unlock_irqrestore(&idev->lock, flags);
}
static void altr_i2c_int_clear(struct altr_i2c_dev *idev, u32 mask)
@@ -158,7 +142,7 @@ static void altr_i2c_init(struct altr_i2c_dev *idev)
(ALTR_I2C_THRESHOLD << ALTR_I2C_CTRL_TCT_SHFT);
u32 t_high, t_low;
- if (idev->bus_clk_rate <= 100000) {
+ if (idev->bus_clk_rate <= I2C_MAX_STANDARD_MODE_FREQ) {
tmp &= ~ALTR_I2C_CTRL_BSPEED;
/* Standard mode SCL 50/50 */
t_high = divisor * 1 / 2;
@@ -182,13 +166,13 @@ static void altr_i2c_init(struct altr_i2c_dev *idev)
/* SCL Low Time */
writel(t_low, idev->base + ALTR_I2C_SCL_LOW);
/* SDA Hold Time, 300ns */
- writel(div_u64(300 * clk_mhz, 1000), idev->base + ALTR_I2C_SDA_HOLD);
+ writel(3 * clk_mhz / 10, idev->base + ALTR_I2C_SDA_HOLD);
- /* Mask all master interrupt bits */
+ /* Mask all interrupt bits */
altr_i2c_int_enable(idev, ALTR_I2C_ALL_IRQ, false);
}
-/**
+/*
* altr_i2c_transfer - On the last byte to be transmitted, send
* a Stop bit on the last byte.
*/
@@ -201,7 +185,7 @@ static void altr_i2c_transfer(struct altr_i2c_dev *idev, u32 data)
writel(data, idev->base + ALTR_I2C_TFR_CMD);
}
-/**
+/*
* altr_i2c_empty_rx_fifo - Fetch data from RX FIFO until end of
* transfer. Send a Stop bit on the last byte.
*/
@@ -217,9 +201,8 @@ static void altr_i2c_empty_rx_fifo(struct altr_i2c_dev *idev)
}
}
-/**
+/*
* altr_i2c_fill_tx_fifo - Fill TX FIFO from current message buffer.
- * @return: Number of bytes left to transfer.
*/
static int altr_i2c_fill_tx_fifo(struct altr_i2c_dev *idev)
{
@@ -256,10 +239,11 @@ static irqreturn_t altr_i2c_isr(int irq, void *_dev)
struct altr_i2c_dev *idev = _dev;
u32 status = idev->isr_status;
+ mutex_lock(&idev->isr_mutex);
if (!idev->msg) {
dev_warn(idev->dev, "unexpected interrupt\n");
altr_i2c_int_clear(idev, ALTR_I2C_ALL_IRQ);
- return IRQ_HANDLED;
+ goto out;
}
read = (idev->msg->flags & I2C_M_RD) != 0;
@@ -312,6 +296,8 @@ static irqreturn_t altr_i2c_isr(int irq, void *_dev)
complete(&idev->msg_complete);
dev_dbg(idev->dev, "Message Complete\n");
}
+out:
+ mutex_unlock(&idev->isr_mutex);
return IRQ_HANDLED;
}
@@ -323,6 +309,7 @@ static int altr_i2c_xfer_msg(struct altr_i2c_dev *idev, struct i2c_msg *msg)
u32 value;
u8 addr = i2c_8bit_addr_from_msg(msg);
+ mutex_lock(&idev->isr_mutex);
idev->msg = msg;
idev->msg_len = msg->len;
idev->buf = msg->buf;
@@ -347,9 +334,11 @@ static int altr_i2c_xfer_msg(struct altr_i2c_dev *idev, struct i2c_msg *msg)
altr_i2c_int_enable(idev, imask, true);
altr_i2c_fill_tx_fifo(idev);
}
+ mutex_unlock(&idev->isr_mutex);
time_left = wait_for_completion_timeout(&idev->msg_complete,
ALTR_I2C_XFER_TIMEOUT);
+ mutex_lock(&idev->isr_mutex);
altr_i2c_int_enable(idev, imask, false);
value = readl(idev->base + ALTR_I2C_STATUS) & ALTR_I2C_STAT_CORE;
@@ -362,6 +351,7 @@ static int altr_i2c_xfer_msg(struct altr_i2c_dev *idev, struct i2c_msg *msg)
}
altr_i2c_core_disable(idev);
+ mutex_unlock(&idev->isr_mutex);
return idev->msg_err;
}
@@ -386,31 +376,26 @@ static u32 altr_i2c_func(struct i2c_adapter *adap)
}
static const struct i2c_algorithm altr_i2c_algo = {
- .master_xfer = altr_i2c_xfer,
+ .xfer = altr_i2c_xfer,
.functionality = altr_i2c_func,
};
static int altr_i2c_probe(struct platform_device *pdev)
{
struct altr_i2c_dev *idev = NULL;
- struct resource *res;
int irq, ret;
- u32 val;
idev = devm_kzalloc(&pdev->dev, sizeof(*idev), GFP_KERNEL);
if (!idev)
return -ENOMEM;
- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- idev->base = devm_ioremap_resource(&pdev->dev, res);
+ idev->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(idev->base))
return PTR_ERR(idev->base);
irq = platform_get_irq(pdev, 0);
- if (irq < 0) {
- dev_err(&pdev->dev, "missing interrupt resource\n");
+ if (irq < 0)
return irq;
- }
idev->i2c_clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(idev->i2c_clk)) {
@@ -420,24 +405,24 @@ static int altr_i2c_probe(struct platform_device *pdev)
idev->dev = &pdev->dev;
init_completion(&idev->msg_complete);
- spin_lock_init(&idev->lock);
+ mutex_init(&idev->isr_mutex);
- val = device_property_read_u32(idev->dev, "fifo-size",
+ ret = device_property_read_u32(idev->dev, "fifo-size",
&idev->fifo_size);
- if (val) {
+ if (ret) {
dev_err(&pdev->dev, "FIFO size set to default of %d\n",
ALTR_I2C_DFLT_FIFO_SZ);
idev->fifo_size = ALTR_I2C_DFLT_FIFO_SZ;
}
- val = device_property_read_u32(idev->dev, "clock-frequency",
+ ret = device_property_read_u32(idev->dev, "clock-frequency",
&idev->bus_clk_rate);
- if (val) {
+ if (ret) {
dev_err(&pdev->dev, "Default to 100kHz\n");
- idev->bus_clk_rate = 100000; /* default clock rate */
+ idev->bus_clk_rate = I2C_MAX_STANDARD_MODE_FREQ; /* default clock rate */
}
- if (idev->bus_clk_rate > 400000) {
+ if (idev->bus_clk_rate > I2C_MAX_FAST_MODE_FREQ) {
dev_err(&pdev->dev, "invalid clock-frequency %d\n",
idev->bus_clk_rate);
return -EINVAL;
@@ -457,10 +442,12 @@ static int altr_i2c_probe(struct platform_device *pdev)
return ret;
}
+ mutex_lock(&idev->isr_mutex);
altr_i2c_init(idev);
+ mutex_unlock(&idev->isr_mutex);
i2c_set_adapdata(&idev->adapter, idev);
- strlcpy(idev->adapter.name, pdev->name, sizeof(idev->adapter.name));
+ strscpy(idev->adapter.name, pdev->name, sizeof(idev->adapter.name));
idev->adapter.owner = THIS_MODULE;
idev->adapter.algo = &altr_i2c_algo;
idev->adapter.dev.parent = &pdev->dev;
@@ -478,14 +465,12 @@ static int altr_i2c_probe(struct platform_device *pdev)
return 0;
}
-static int altr_i2c_remove(struct platform_device *pdev)
+static void altr_i2c_remove(struct platform_device *pdev)
{
struct altr_i2c_dev *idev = platform_get_drvdata(pdev);
clk_disable_unprepare(idev->i2c_clk);
i2c_del_adapter(&idev->adapter);
-
- return 0;
}
/* Match table for of_platform binding */
generated by cgit (git 2.34.1) at 2025-12-25 08:46:00 +0000