ARM: mach-shmobile: r8a7740: add i2c support
This patch adds I2C support to r8a7740 CPU
which has lasting errata on I2C I/O pad reset.
This patch is including work-around.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/arm/mach-shmobile/setup-r8a7740.c b/arch/arm/mach-shmobile/setup-r8a7740.c
index 5548518..e16860f 100644
--- a/arch/arm/mach-shmobile/setup-r8a7740.c
+++ b/arch/arm/mach-shmobile/setup-r8a7740.c
@@ -17,8 +17,10 @@
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
+#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/init.h>
+#include <linux/io.h>
#include <linux/platform_device.h>
#include <linux/serial_sci.h>
#include <linux/sh_timer.h>
@@ -233,10 +235,114 @@
&cmt10_device,
};
+/* I2C */
+static struct resource i2c0_resources[] = {
+ [0] = {
+ .name = "IIC0",
+ .start = 0xfff20000,
+ .end = 0xfff20425 - 1,
+ .flags = IORESOURCE_MEM,
+ },
+ [1] = {
+ .start = gic_spi(201),
+ .end = gic_spi(204),
+ .flags = IORESOURCE_IRQ,
+ },
+};
+
+static struct resource i2c1_resources[] = {
+ [0] = {
+ .name = "IIC1",
+ .start = 0xe6c20000,
+ .end = 0xe6c20425 - 1,
+ .flags = IORESOURCE_MEM,
+ },
+ [1] = {
+ .start = gic_spi(70),
+ .end = gic_spi(73),
+ .flags = IORESOURCE_IRQ,
+ },
+};
+
+static struct platform_device i2c0_device = {
+ .name = "i2c-sh_mobile",
+ .id = 0,
+ .resource = i2c0_resources,
+ .num_resources = ARRAY_SIZE(i2c0_resources),
+};
+
+static struct platform_device i2c1_device = {
+ .name = "i2c-sh_mobile",
+ .id = 1,
+ .resource = i2c1_resources,
+ .num_resources = ARRAY_SIZE(i2c1_resources),
+};
+
+static struct platform_device *r8a7740_late_devices[] __initdata = {
+ &i2c0_device,
+ &i2c1_device,
+};
+
+#define ICCR 0x0004
+#define ICSTART 0x0070
+
+#define i2c_read(reg, offset) ioread8(reg + offset)
+#define i2c_write(reg, offset, data) iowrite8(data, reg + offset)
+
+/*
+ * r8a7740 chip has lasting errata on I2C I/O pad reset.
+ * this is work-around for it.
+ */
+static void r8a7740_i2c_workaround(struct platform_device *pdev)
+{
+ struct resource *res;
+ void __iomem *reg;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (unlikely(!res)) {
+ pr_err("r8a7740 i2c workaround fail (cannot find resource)\n");
+ return;
+ }
+
+ reg = ioremap(res->start, resource_size(res));
+ if (unlikely(!reg)) {
+ pr_err("r8a7740 i2c workaround fail (cannot map IO)\n");
+ return;
+ }
+
+ i2c_write(reg, ICCR, i2c_read(reg, ICCR) | 0x80);
+ i2c_read(reg, ICCR); /* dummy read */
+
+ i2c_write(reg, ICSTART, i2c_read(reg, ICSTART) | 0x10);
+ i2c_read(reg, ICSTART); /* dummy read */
+
+ mdelay(100);
+
+ i2c_write(reg, ICCR, 0x01);
+ i2c_read(reg, ICCR);
+ i2c_write(reg, ICSTART, 0x00);
+ i2c_read(reg, ICSTART);
+
+ i2c_write(reg, ICCR, 0x10);
+ mdelay(100);
+ i2c_write(reg, ICCR, 0x00);
+ mdelay(100);
+ i2c_write(reg, ICCR, 0x10);
+ mdelay(100);
+
+ iounmap(reg);
+}
+
void __init r8a7740_add_standard_devices(void)
{
+ /* I2C work-around */
+ r8a7740_i2c_workaround(&i2c0_device);
+ r8a7740_i2c_workaround(&i2c1_device);
+
platform_add_devices(r8a7740_early_devices,
ARRAY_SIZE(r8a7740_early_devices));
+ platform_add_devices(r8a7740_late_devices,
+ ARRAY_SIZE(r8a7740_late_devices));
}
void __init r8a7740_add_early_devices(void)