[PATCH] i2c: viai2c: turn common code into a proper module
From: Arnd Bergmann
Date: Tue May 28 2024 - 08:07:27 EST
From: Arnd Bergmann <arnd@xxxxxxxx>
The i2c-viai2c-common.c file is used by two drivers, but is not a proper
abstraction and can get linked into both modules in the same configuration,
which results in a warning:
scripts/Makefile.build:236: drivers/i2c/busses/Makefile: i2c-viai2c-common.o is added to multiple modules: i2c-wmt i2c-zhaoxin
The other problems with this include the incorrect use of a __weak function
when both are built-in, and the fact that the "common" module is sprinked
with 'if (i2c->plat == ...)' checks that have knowledge about the differences
between the drivers using it.
Avoid the link time warning by making the common driver a proper module
with MODULE_LICENCE()/MODULE_AUTHOR() tags, and remove the __weak function
by slightly rearranging the code.
This adds a little more duplication between the two main drivers, but
those versions get more readable in the process.
Fixes: a06b80e83011 ("i2c: add zhaoxin i2c controller driver")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/i2c/busses/Makefile | 6 +-
drivers/i2c/busses/i2c-viai2c-common.c | 71 ++-------------
drivers/i2c/busses/i2c-viai2c-common.h | 2 +-
drivers/i2c/busses/i2c-viai2c-wmt.c | 37 ++++++++
drivers/i2c/busses/i2c-viai2c-zhaoxin.c | 113 +++++++++++++++++++-----
5 files changed, 140 insertions(+), 89 deletions(-)
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 3d65934f5eb4..78d0561339e5 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -29,8 +29,7 @@ obj-$(CONFIG_I2C_SIS630) += i2c-sis630.o
obj-$(CONFIG_I2C_SIS96X) += i2c-sis96x.o
obj-$(CONFIG_I2C_VIA) += i2c-via.o
obj-$(CONFIG_I2C_VIAPRO) += i2c-viapro.o
-i2c-zhaoxin-objs := i2c-viai2c-zhaoxin.o i2c-viai2c-common.o
-obj-$(CONFIG_I2C_ZHAOXIN) += i2c-zhaoxin.o
+obj-$(CONFIG_I2C_ZHAOXIN) += i2c-viai2c-zhaoxin.o i2c-viai2c-common.o
# Mac SMBus host controller drivers
obj-$(CONFIG_I2C_HYDRA) += i2c-hydra.o
@@ -120,8 +119,7 @@ obj-$(CONFIG_I2C_TEGRA_BPMP) += i2c-tegra-bpmp.o
obj-$(CONFIG_I2C_UNIPHIER) += i2c-uniphier.o
obj-$(CONFIG_I2C_UNIPHIER_F) += i2c-uniphier-f.o
obj-$(CONFIG_I2C_VERSATILE) += i2c-versatile.o
-i2c-wmt-objs := i2c-viai2c-wmt.o i2c-viai2c-common.o
-obj-$(CONFIG_I2C_WMT) += i2c-wmt.o
+obj-$(CONFIG_I2C_WMT) += i2c-viai2c-wmt.o i2c-viai2c-common.o
i2c-octeon-objs := i2c-octeon-core.o i2c-octeon-platdrv.o
obj-$(CONFIG_I2C_OCTEON) += i2c-octeon.o
i2c-thunderx-objs := i2c-octeon-core.o i2c-thunderx-pcidrv.o
diff --git a/drivers/i2c/busses/i2c-viai2c-common.c b/drivers/i2c/busses/i2c-viai2c-common.c
index 1844d13f1f79..162b31306cba 100644
--- a/drivers/i2c/busses/i2c-viai2c-common.c
+++ b/drivers/i2c/busses/i2c-viai2c-common.c
@@ -17,6 +17,7 @@ int viai2c_wait_bus_not_busy(struct viai2c *i2c)
return 0;
}
+EXPORT_SYMBOL_GPL(viai2c_wait_bus_not_busy);
static int viai2c_write(struct viai2c *i2c, struct i2c_msg *pmsg, int last)
{
@@ -121,6 +122,7 @@ int viai2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
return (ret < 0) ? ret : i;
}
+EXPORT_SYMBOL_GPL(viai2c_xfer);
/*
* Main process of the byte mode xfer
@@ -130,7 +132,7 @@ int viai2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
* 0: there is still data that needs to be transferred
* -EIO: error occurred
*/
-static int viai2c_irq_xfer(struct viai2c *i2c)
+int viai2c_irq_xfer(struct viai2c *i2c)
{
u16 val;
struct i2c_msg *msg = i2c->msg;
@@ -171,51 +173,11 @@ static int viai2c_irq_xfer(struct viai2c *i2c)
return i2c->xfered_len == msg->len;
}
-
-int __weak viai2c_fifo_irq_xfer(struct viai2c *i2c, bool irq)
-{
- return 0;
-}
-
-static irqreturn_t viai2c_isr(int irq, void *data)
-{
- struct viai2c *i2c = data;
- u8 status;
-
- /* save the status and write-clear it */
- status = readw(i2c->base + VIAI2C_REG_ISR);
- if (!status && i2c->platform == VIAI2C_PLAT_ZHAOXIN)
- return IRQ_NONE;
-
- writew(status, i2c->base + VIAI2C_REG_ISR);
-
- i2c->ret = 0;
- if (status & VIAI2C_ISR_NACK_ADDR)
- i2c->ret = -EIO;
-
- if (i2c->platform == VIAI2C_PLAT_WMT && (status & VIAI2C_ISR_SCL_TIMEOUT))
- i2c->ret = -ETIMEDOUT;
-
- if (!i2c->ret) {
- if (i2c->mode == VIAI2C_BYTE_MODE)
- i2c->ret = viai2c_irq_xfer(i2c);
- else
- i2c->ret = viai2c_fifo_irq_xfer(i2c, true);
- }
-
- /* All the data has been successfully transferred or error occurred */
- if (i2c->ret)
- complete(&i2c->complete);
-
- return IRQ_HANDLED;
-}
+EXPORT_SYMBOL_GPL(viai2c_irq_xfer);
int viai2c_init(struct platform_device *pdev, struct viai2c **pi2c, int plat)
{
- int err;
- int irq_flags;
struct viai2c *i2c;
- struct device_node *np = pdev->dev.of_node;
i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);
if (!i2c)
@@ -225,28 +187,8 @@ int viai2c_init(struct platform_device *pdev, struct viai2c **pi2c, int plat)
if (IS_ERR(i2c->base))
return PTR_ERR(i2c->base);
- if (plat == VIAI2C_PLAT_WMT) {
- irq_flags = 0;
- i2c->irq = irq_of_parse_and_map(np, 0);
- if (!i2c->irq)
- return -EINVAL;
- } else if (plat == VIAI2C_PLAT_ZHAOXIN) {
- irq_flags = IRQF_SHARED;
- i2c->irq = platform_get_irq(pdev, 0);
- if (i2c->irq < 0)
- return i2c->irq;
- } else {
- return dev_err_probe(&pdev->dev, -EINVAL, "wrong platform type\n");
- }
-
i2c->platform = plat;
- err = devm_request_irq(&pdev->dev, i2c->irq, viai2c_isr,
- irq_flags, pdev->name, i2c);
- if (err)
- return dev_err_probe(&pdev->dev, err,
- "failed to request irq %i\n", i2c->irq);
-
i2c->dev = &pdev->dev;
init_completion(&i2c->complete);
platform_set_drvdata(pdev, i2c);
@@ -254,3 +196,8 @@ int viai2c_init(struct platform_device *pdev, struct viai2c **pi2c, int plat)
*pi2c = i2c;
return 0;
}
+EXPORT_SYMBOL_GPL(viai2c_init);
+
+MODULE_DESCRIPTION("Via/Wondermedia/Zhaoxin I2C master-mode bus adapter");
+MODULE_AUTHOR("Tony Prisk <linux@xxxxxxxxxxxxxxx>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/i2c/busses/i2c-viai2c-common.h b/drivers/i2c/busses/i2c-viai2c-common.h
index 81e827c54434..00f17733223c 100644
--- a/drivers/i2c/busses/i2c-viai2c-common.h
+++ b/drivers/i2c/busses/i2c-viai2c-common.h
@@ -80,6 +80,6 @@ struct viai2c {
int viai2c_wait_bus_not_busy(struct viai2c *i2c);
int viai2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num);
int viai2c_init(struct platform_device *pdev, struct viai2c **pi2c, int plat);
-int viai2c_fifo_irq_xfer(struct viai2c *i2c, bool irq);
+int viai2c_irq_xfer(struct viai2c *i2c);
#endif
diff --git a/drivers/i2c/busses/i2c-viai2c-wmt.c b/drivers/i2c/busses/i2c-viai2c-wmt.c
index e1988f946026..b3ab9633015a 100644
--- a/drivers/i2c/busses/i2c-viai2c-wmt.c
+++ b/drivers/i2c/busses/i2c-viai2c-wmt.c
@@ -72,6 +72,33 @@ static int wmt_i2c_reset_hardware(struct viai2c *i2c)
return 0;
}
+static irqreturn_t wmt_i2c_isr(int irq, void *data)
+{
+ struct viai2c *i2c = data;
+ u8 status;
+
+ /* save the status and write-clear it */
+ status = readw(i2c->base + VIAI2C_REG_ISR);
+ writew(status, i2c->base + VIAI2C_REG_ISR);
+
+ i2c->ret = 0;
+ if (status & VIAI2C_ISR_NACK_ADDR)
+ i2c->ret = -EIO;
+
+ if (status & VIAI2C_ISR_SCL_TIMEOUT)
+ i2c->ret = -ETIMEDOUT;
+
+ if (!i2c->ret)
+ i2c->ret = viai2c_irq_xfer(i2c);
+
+ /* All the data has been successfully transferred or error occurred */
+ if (i2c->ret)
+ complete(&i2c->complete);
+
+ return IRQ_HANDLED;
+}
+
+
static int wmt_i2c_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
@@ -84,6 +111,16 @@ static int wmt_i2c_probe(struct platform_device *pdev)
if (err)
return err;
+ i2c->irq = platform_get_irq(pdev, 0);
+ if (i2c->irq < 0)
+ return i2c->irq;
+
+ err = devm_request_irq(&pdev->dev, i2c->irq, wmt_i2c_isr,
+ 0, pdev->name, i2c);
+ if (err)
+ return dev_err_probe(&pdev->dev, err,
+ "failed to request irq %i\n", i2c->irq);
+
i2c->clk = of_clk_get(np, 0);
if (IS_ERR(i2c->clk)) {
dev_err(&pdev->dev, "unable to request clock\n");
diff --git a/drivers/i2c/busses/i2c-viai2c-zhaoxin.c b/drivers/i2c/busses/i2c-viai2c-zhaoxin.c
index 7e3ac2a3e1fd..dbcb904c74f0 100644
--- a/drivers/i2c/busses/i2c-viai2c-zhaoxin.c
+++ b/drivers/i2c/busses/i2c-viai2c-zhaoxin.c
@@ -49,8 +49,7 @@ struct viai2c_zhaoxin {
u16 xfer_len;
};
-/* 'irq == true' means in interrupt context */
-int viai2c_fifo_irq_xfer(struct viai2c *i2c, bool irq)
+static int viai2c_fifo_xfer(struct viai2c *i2c)
{
u16 i;
u8 tmp;
@@ -59,17 +58,6 @@ int viai2c_fifo_irq_xfer(struct viai2c *i2c, bool irq)
bool read = !!(msg->flags & I2C_M_RD);
struct viai2c_zhaoxin *priv = i2c->pltfm_priv;
- if (irq) {
- /* get the received data */
- if (read)
- for (i = 0; i < priv->xfer_len; i++)
- msg->buf[i2c->xfered_len + i] = ioread8(base + ZXI2C_REG_HRDR);
-
- i2c->xfered_len += priv->xfer_len;
- if (i2c->xfered_len == msg->len)
- return 1;
- }
-
/* reset fifo buffer */
tmp = ioread8(base + ZXI2C_REG_HCR);
iowrite8(tmp | ZXI2C_HCR_RST_FIFO, base + ZXI2C_REG_HCR);
@@ -92,18 +80,59 @@ int viai2c_fifo_irq_xfer(struct viai2c *i2c, bool irq)
iowrite8(tmp, base + VIAI2C_REG_CR);
}
- if (irq) {
- /* continue transmission */
- tmp = ioread8(base + VIAI2C_REG_CR);
- iowrite8(tmp |= VIAI2C_CR_CPU_RDY, base + VIAI2C_REG_CR);
+ u16 tcr_val = i2c->tcr;
+
+ /* start transmission */
+ tcr_val |= read ? VIAI2C_TCR_READ : 0;
+ writew(tcr_val | msg->addr, base + VIAI2C_REG_TCR);
+
+ return 0;
+}
+
+static int viai2c_fifo_irq_xfer(struct viai2c *i2c)
+{
+ u16 i;
+ u8 tmp;
+ struct i2c_msg *msg = i2c->msg;
+ void __iomem *base = i2c->base;
+ bool read = !!(msg->flags & I2C_M_RD);
+ struct viai2c_zhaoxin *priv = i2c->pltfm_priv;
+
+ /* get the received data */
+ if (read)
+ for (i = 0; i < priv->xfer_len; i++)
+ msg->buf[i2c->xfered_len + i] = ioread8(base + ZXI2C_REG_HRDR);
+
+ i2c->xfered_len += priv->xfer_len;
+ if (i2c->xfered_len == msg->len)
+ return 1;
+
+ /* reset fifo buffer */
+ tmp = ioread8(base + ZXI2C_REG_HCR);
+ iowrite8(tmp | ZXI2C_HCR_RST_FIFO, base + ZXI2C_REG_HCR);
+
+ /* set xfer len */
+ priv->xfer_len = min_t(u16, msg->len - i2c->xfered_len, ZXI2C_FIFO_SIZE);
+ if (read) {
+ iowrite8(priv->xfer_len - 1, base + ZXI2C_REG_HRLR);
} else {
- u16 tcr_val = i2c->tcr;
+ iowrite8(priv->xfer_len - 1, base + ZXI2C_REG_HTLR);
+ /* set write data */
+ for (i = 0; i < priv->xfer_len; i++)
+ iowrite8(msg->buf[i2c->xfered_len + i], base + ZXI2C_REG_HTDR);
+ }
- /* start transmission */
- tcr_val |= read ? VIAI2C_TCR_READ : 0;
- writew(tcr_val | msg->addr, base + VIAI2C_REG_TCR);
+ /* prepare to stop transmission */
+ if (priv->hrv && msg->len == (i2c->xfered_len + priv->xfer_len)) {
+ tmp = ioread8(base + VIAI2C_REG_CR);
+ tmp |= read ? VIAI2C_CR_RX_END : VIAI2C_CR_TX_END;
+ iowrite8(tmp, base + VIAI2C_REG_CR);
}
+ /* continue transmission */
+ tmp = ioread8(base + VIAI2C_REG_CR);
+ iowrite8(tmp |= VIAI2C_CR_CPU_RDY, base + VIAI2C_REG_CR);
+
return 0;
}
@@ -135,7 +164,7 @@ static int zxi2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int
priv->xfer_len = 0;
i2c->xfered_len = 0;
- viai2c_fifo_irq_xfer(i2c, 0);
+ viai2c_fifo_xfer(i2c);
if (!wait_for_completion_timeout(&i2c->complete, VIAI2C_TIMEOUT))
return -ETIMEDOUT;
@@ -228,6 +257,36 @@ static void zxi2c_get_bus_speed(struct viai2c *i2c)
dev_info(i2c->dev, "speed mode is %s\n", i2c_freq_mode_string(params[0]));
}
+static irqreturn_t zxi2c_isr(int irq, void *data)
+{
+ struct viai2c *i2c = data;
+ u8 status;
+
+ /* save the status and write-clear it */
+ status = readw(i2c->base + VIAI2C_REG_ISR);
+ if (!status)
+ return IRQ_NONE;
+
+ writew(status, i2c->base + VIAI2C_REG_ISR);
+
+ i2c->ret = 0;
+ if (status & VIAI2C_ISR_NACK_ADDR)
+ i2c->ret = -EIO;
+
+ if (!i2c->ret) {
+ if (i2c->mode == VIAI2C_BYTE_MODE)
+ i2c->ret = viai2c_irq_xfer(i2c);
+ else
+ i2c->ret = viai2c_fifo_irq_xfer(i2c);
+ }
+
+ /* All the data has been successfully transferred or error occurred */
+ if (i2c->ret)
+ complete(&i2c->complete);
+
+ return IRQ_HANDLED;
+}
+
static int zxi2c_probe(struct platform_device *pdev)
{
int error;
@@ -239,6 +298,16 @@ static int zxi2c_probe(struct platform_device *pdev)
if (error)
return error;
+ i2c->irq = platform_get_irq(pdev, 0);
+ if (i2c->irq < 0)
+ return i2c->irq;
+
+ error = devm_request_irq(&pdev->dev, i2c->irq, zxi2c_isr,
+ IRQF_SHARED, pdev->name, i2c);
+ if (error)
+ return dev_err_probe(&pdev->dev, error,
+ "failed to request irq %i\n", i2c->irq);
+
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
--
2.39.2