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-rw-r--r--Documentation/devicetree/bindings/i2c/i2c-ocores.txt8
-rw-r--r--drivers/i2c/busses/i2c-ocores.c36
-rw-r--r--include/linux/i2c-ocores.h2
3 files changed, 29 insertions, 17 deletions
diff --git a/Documentation/devicetree/bindings/i2c/i2c-ocores.txt b/Documentation/devicetree/bindings/i2c/i2c-ocores.txt
index bfec8941509c..1c9334bfc39c 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-ocores.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-ocores.txt
@@ -4,11 +4,14 @@ Required properties:
- compatible : "opencores,i2c-ocores"
- reg : bus address start and address range size of device
- interrupts : interrupt number
-- regstep : size of device registers in bytes
- clock-frequency : frequency of bus clock in Hz
- #address-cells : should be <1>
- #size-cells : should be <0>
+Optional properties:
+- reg-shift : device register offsets are shifted by this value
+- regstep : deprecated, use reg-shift above
+
Example:
i2c0: ocores@a0000000 {
@@ -17,9 +20,10 @@ Example:
compatible = "opencores,i2c-ocores";
reg = <0xa0000000 0x8>;
interrupts = <10>;
- regstep = <1>;
clock-frequency = <20000000>;
+ reg-shift = <0>; /* 8 bit registers */
+
dummy@60 {
compatible = "dummy";
reg = <0x60>;
diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c
index f6e7ad9f60e9..9e0709d5fb36 100644
--- a/drivers/i2c/busses/i2c-ocores.c
+++ b/drivers/i2c/busses/i2c-ocores.c
@@ -25,10 +25,11 @@
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/of_i2c.h>
+#include <linux/log2.h>
struct ocores_i2c {
void __iomem *base;
- int regstep;
+ u32 reg_shift;
wait_queue_head_t wait;
struct i2c_adapter adap;
struct i2c_msg *msg;
@@ -71,12 +72,12 @@ struct ocores_i2c {
static inline void oc_setreg(struct ocores_i2c *i2c, int reg, u8 value)
{
- iowrite8(value, i2c->base + reg * i2c->regstep);
+ iowrite8(value, i2c->base + (reg << i2c->reg_shift));
}
static inline u8 oc_getreg(struct ocores_i2c *i2c, int reg)
{
- return ioread8(i2c->base + reg * i2c->regstep);
+ return ioread8(i2c->base + (reg << i2c->reg_shift));
}
static void ocores_process(struct ocores_i2c *i2c)
@@ -219,22 +220,29 @@ static struct i2c_adapter ocores_adapter = {
static int ocores_i2c_of_probe(struct platform_device *pdev,
struct ocores_i2c *i2c)
{
- const __be32* val;
-
- val = of_get_property(pdev->dev.of_node, "regstep", NULL);
- if (!val) {
- dev_err(&pdev->dev, "Missing required parameter 'regstep'\n");
- return -ENODEV;
+ struct device_node *np = pdev->dev.of_node;
+ u32 val;
+
+ if (of_property_read_u32(np, "reg-shift", &i2c->reg_shift)) {
+ /* no 'reg-shift', check for deprecated 'regstep' */
+ if (!of_property_read_u32(np, "regstep", &val)) {
+ if (!is_power_of_2(val)) {
+ dev_err(&pdev->dev, "invalid regstep %d\n",
+ val);
+ return -EINVAL;
+ }
+ i2c->reg_shift = ilog2(val);
+ dev_warn(&pdev->dev,
+ "regstep property deprecated, use reg-shift\n");
+ }
}
- i2c->regstep = be32_to_cpup(val);
- val = of_get_property(pdev->dev.of_node, "clock-frequency", NULL);
- if (!val) {
+ if (of_property_read_u32(np, "clock-frequency", &val)) {
dev_err(&pdev->dev,
"Missing required parameter 'clock-frequency'\n");
return -ENODEV;
}
- i2c->clock_khz = be32_to_cpup(val) / 1000;
+ i2c->clock_khz = val / 1000;
return 0;
}
@@ -277,7 +285,7 @@ static int __devinit ocores_i2c_probe(struct platform_device *pdev)
pdata = pdev->dev.platform_data;
if (pdata) {
- i2c->regstep = pdata->regstep;
+ i2c->reg_shift = pdata->reg_shift;
i2c->clock_khz = pdata->clock_khz;
} else {
ret = ocores_i2c_of_probe(pdev, i2c);
diff --git a/include/linux/i2c-ocores.h b/include/linux/i2c-ocores.h
index 4d5e57ff6614..5d95df2436f4 100644
--- a/include/linux/i2c-ocores.h
+++ b/include/linux/i2c-ocores.h
@@ -12,7 +12,7 @@
#define _LINUX_I2C_OCORES_H
struct ocores_i2c_platform_data {
- u32 regstep; /* distance between registers */
+ u32 reg_shift; /* register offset shift value */
u32 clock_khz; /* input clock in kHz */
u8 num_devices; /* number of devices in the devices list */
struct i2c_board_info const *devices; /* devices connected to the bus */
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