[PATCH v4] i2c: Add device tree support to i2c-pnx.c
Roland Stigge
stigge at antcom.de
Fri Apr 20 01:50:12 EST 2012
This patch adds device tree support to the pnx-i2c driver by using platform
resources for memory region and irq and removing dependency on mach includes.
The following platforms are affected:
* PNX
* LPC31xx (WIP)
* LPC32xx
The patch is based on a patch by Jon Smirl, working on lpc31xx integration
Signed-off-by: Roland Stigge <stigge at antcom.de>
Reviewed-by: Arnd Bergmann <arnd at arndb.de>
---
Applies to v3.4-rc3 + already applied i2c-pnx.c patches from this series
NOTE: I separated out this patch from the first patch series of the LPC32xx
device tree conversion because most of those patches are already applied to
-next. This is the last patch of this first series, a precondition for the
LPC32xx device tree switch.
Changes since v3:
* Documentation/devicetree/bindings/i2c/pnx.txt:
- Documented interrupt-parent as required
- Documented slave-addr default in hex
Documentation/devicetree/bindings/i2c/pnx.txt | 40 ++++++++++++++++
drivers/i2c/busses/i2c-pnx.c | 65 +++++++++++++++++++-------
include/linux/i2c-pnx.h | 1
3 files changed, 89 insertions(+), 17 deletions(-)
--- /dev/null
+++ linux-2.6/Documentation/devicetree/bindings/i2c/pnx.txt
@@ -0,0 +1,40 @@
+* NXP PNX I2C Controller
+
+Required properties:
+
+ - reg: Offset and length of the register set for the device
+ - compatible: should be "nxp,pnx-i2c"
+ - interrupts: configure one interrupt line
+ - #address-cells: always 1 (for i2c addresses)
+ - #size-cells: always 0
+ - interrupt-parent: the phandle for the interrupt controller that
+ services interrupts for this device.
+
+Optional properties:
+
+ - clock-frequency: desired I2C bus clock frequency in Hz, Default: 100000 Hz
+ - pnx,timeout: I2C bus timeout in milliseconds, Default: 10 ms
+ - slave-addr: Address used by the controller, Hardware default: 0x6e
+
+Examples:
+
+ i2c1: i2c at 400a0000 {
+ compatible = "nxp,pnx-i2c";
+ reg = <0x400a0000 0x100>;
+ interrupt-parent = <&mic>;
+ interrupts = <51 0>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ };
+
+ i2c2: i2c at 400a8000 {
+ compatible = "nxp,pnx-i2c";
+ reg = <0x400a8000 0x100>;
+ interrupt-parent = <&mic>;
+ interrupts = <50 0>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ clock-frequency = <0x186a0>;
+ pnx,timeout = <0x64>;
+ slave-addr = <0x11>;
+ };
--- linux-2.6.orig/drivers/i2c/busses/i2c-pnx.c
+++ linux-2.6/drivers/i2c/busses/i2c-pnx.c
@@ -23,10 +23,11 @@
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/slab.h>
+#include <linux/of_i2c.h>
-#define I2C_PNX_TIMEOUT 10 /* msec */
-#define I2C_PNX_SPEED_KHZ 100
-#define I2C_PNX_REGION_SIZE 0x100
+#define I2C_PNX_TIMEOUT_DEFAULT 10 /* msec */
+#define I2C_PNX_SPEED_KHZ_DEFAULT 100
+#define I2C_PNX_REGION_SIZE 0x100
enum {
mstatus_tdi = 0x00000001,
@@ -74,8 +75,9 @@ enum {
#define I2C_REG_TXS(a) ((a)->ioaddr + 0x28) /* Tx slave FIFO (RO) */
#define I2C_REG_STFL(a) ((a)->ioaddr + 0x2c) /* Tx slave FIFO level (RO) */
-static inline int wait_timeout(long timeout, struct i2c_pnx_algo_data *data)
+static inline int wait_timeout(struct i2c_pnx_algo_data *data)
{
+ long timeout = data->timeout;
while (timeout > 0 &&
(ioread32(I2C_REG_STS(data)) & mstatus_active)) {
mdelay(1);
@@ -84,8 +86,9 @@ static inline int wait_timeout(long time
return (timeout <= 0);
}
-static inline int wait_reset(long timeout, struct i2c_pnx_algo_data *data)
+static inline int wait_reset(struct i2c_pnx_algo_data *data)
{
+ long timeout = data->timeout;
while (timeout > 0 &&
(ioread32(I2C_REG_CTL(data)) & mcntrl_reset)) {
mdelay(1);
@@ -97,7 +100,7 @@ static inline int wait_reset(long timeou
static inline void i2c_pnx_arm_timer(struct i2c_pnx_algo_data *alg_data)
{
struct timer_list *timer = &alg_data->mif.timer;
- unsigned long expires = msecs_to_jiffies(I2C_PNX_TIMEOUT);
+ unsigned long expires = msecs_to_jiffies(alg_data->timeout);
if (expires <= 1)
expires = 2;
@@ -135,7 +138,7 @@ static int i2c_pnx_start(unsigned char s
}
/* First, make sure bus is idle */
- if (wait_timeout(I2C_PNX_TIMEOUT, alg_data)) {
+ if (wait_timeout(alg_data)) {
/* Somebody else is monopolizing the bus */
dev_err(&alg_data->adapter.dev,
"%s: Bus busy. Slave addr = %02x, cntrl = %x, stat = %x\n",
@@ -228,7 +231,7 @@ static int i2c_pnx_master_xmit(struct i2
if (alg_data->mif.len == 0) {
if (alg_data->last) {
/* Wait until the STOP is seen. */
- if (wait_timeout(I2C_PNX_TIMEOUT, alg_data))
+ if (wait_timeout(alg_data))
dev_err(&alg_data->adapter.dev,
"The bus is still active after timeout\n");
}
@@ -326,7 +329,7 @@ static int i2c_pnx_master_rcv(struct i2c
if (alg_data->mif.len == 0) {
if (alg_data->last)
/* Wait until the STOP is seen. */
- if (wait_timeout(I2C_PNX_TIMEOUT, alg_data))
+ if (wait_timeout(alg_data))
dev_err(&alg_data->adapter.dev,
"The bus is still active after timeout\n");
@@ -442,7 +445,7 @@ static void i2c_pnx_timeout(unsigned lon
ctl |= mcntrl_reset;
iowrite32(ctl, I2C_REG_CTL(alg_data));
- wait_reset(I2C_PNX_TIMEOUT, alg_data);
+ wait_reset(alg_data);
alg_data->mif.ret = -EIO;
complete(&alg_data->mif.complete);
}
@@ -457,18 +460,18 @@ static inline void bus_reset_if_active(s
alg_data->adapter.name);
iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_reset,
I2C_REG_CTL(alg_data));
- wait_reset(I2C_PNX_TIMEOUT, alg_data);
+ wait_reset(alg_data);
} else if (!(stat & mstatus_rfe) || !(stat & mstatus_tfe)) {
/* If there is data in the fifo's after transfer,
* flush fifo's by reset.
*/
iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_reset,
I2C_REG_CTL(alg_data));
- wait_reset(I2C_PNX_TIMEOUT, alg_data);
+ wait_reset(alg_data);
} else if (stat & mstatus_nai) {
iowrite32(ioread32(I2C_REG_CTL(alg_data)) | mcntrl_reset,
I2C_REG_CTL(alg_data));
- wait_reset(I2C_PNX_TIMEOUT, alg_data);
+ wait_reset(alg_data);
}
}
@@ -612,6 +615,8 @@ static int __devinit i2c_pnx_probe(struc
struct i2c_pnx_algo_data *alg_data;
unsigned long freq;
struct resource *res;
+ u32 speed = I2C_PNX_SPEED_KHZ_DEFAULT * 1000;
+ u32 slave_addr = ~0;
alg_data = kzalloc(sizeof(*alg_data), GFP_KERNEL);
if (!alg_data) {
@@ -626,6 +631,18 @@ static int __devinit i2c_pnx_probe(struc
alg_data->adapter.algo_data = alg_data;
alg_data->adapter.nr = pdev->id;
+ alg_data->timeout = I2C_PNX_TIMEOUT_DEFAULT;
+#ifdef CONFIG_OF
+ alg_data->adapter.dev.of_node = of_node_get(pdev->dev.of_node);
+ if (pdev->dev.of_node) {
+ of_property_read_u32(pdev->dev.of_node, "pnx,timeout",
+ &alg_data->timeout);
+ of_property_read_u32(pdev->dev.of_node, "clock-frequency",
+ &speed);
+ of_property_read_u32(pdev->dev.of_node, "slave-addr",
+ &slave_addr);
+ }
+#endif
alg_data->clk = clk_get(&pdev->dev, NULL);
if (IS_ERR(alg_data->clk)) {
ret = PTR_ERR(alg_data->clk);
@@ -651,7 +668,7 @@ static int __devinit i2c_pnx_probe(struc
dev_err(&pdev->dev,
"I/O region 0x%08x for I2C already in use.\n",
res->start);
- ret = -ENODEV;
+ ret = -ENOMEM;
goto out_clkget;
}
@@ -667,6 +684,9 @@ static int __devinit i2c_pnx_probe(struc
if (ret)
goto out_unmap;
+ if (slave_addr != ~0)
+ iowrite32(slave_addr, I2C_REG_ADR(alg_data));
+
freq = clk_get_rate(alg_data->clk);
/*
@@ -680,14 +700,14 @@ static int __devinit i2c_pnx_probe(struc
* the deglitching filter length.
*/
- tmp = ((freq / 1000) / I2C_PNX_SPEED_KHZ) / 2 - 2;
+ tmp = (freq / speed) / 2 - 2;
if (tmp > 0x3FF)
tmp = 0x3FF;
iowrite32(tmp, I2C_REG_CKH(alg_data));
iowrite32(tmp, I2C_REG_CKL(alg_data));
iowrite32(mcntrl_reset, I2C_REG_CTL(alg_data));
- if (wait_reset(I2C_PNX_TIMEOUT, alg_data)) {
+ if (wait_reset(alg_data)) {
ret = -ENODEV;
goto out_clock;
}
@@ -699,7 +719,7 @@ static int __devinit i2c_pnx_probe(struc
goto out_irq;
}
ret = request_irq(alg_data->irq, i2c_pnx_interrupt,
- 0, pdev->name, alg_data);
+ 0, pdev->name, alg_data);
if (ret)
goto out_clock;
@@ -710,6 +730,8 @@ static int __devinit i2c_pnx_probe(struc
goto out_irq;
}
+ of_i2c_register_devices(&alg_data->adapter);
+
dev_dbg(&pdev->dev, "%s: Master at %#8x, irq %d.\n",
alg_data->adapter.name, res->start, alg_data->irq);
@@ -748,10 +770,19 @@ static int __devexit i2c_pnx_remove(stru
return 0;
}
+#ifdef CONFIG_OF
+static const struct of_device_id i2c_pnx_of_match[] = {
+ { .compatible = "nxp,pnx-i2c" },
+ { },
+};
+MODULE_DEVICE_TABLE(of, i2c_pnx_of_match);
+#endif
+
static struct platform_driver i2c_pnx_driver = {
.driver = {
.name = "pnx-i2c",
.owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(i2c_pnx_of_match),
},
.probe = i2c_pnx_probe,
.remove = __devexit_p(i2c_pnx_remove),
--- linux-2.6.orig/include/linux/i2c-pnx.h
+++ linux-2.6/include/linux/i2c-pnx.h
@@ -32,6 +32,7 @@ struct i2c_pnx_algo_data {
struct i2c_adapter adapter;
phys_addr_t base;
int irq;
+ u32 timeout;
};
#endif /* __I2C_PNX_H__ */
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