OMAP4: I2C: Add hwspinlock support

Adding support for hwspinlock in I2C driver
in Blaze and Blaze_Tablet2.
Also adding an api omap_i2c_get_hwspinlockid to be
used by remote proc to populate the resource table.

Change-Id: I5f554ead10806c90442359365dcb8ebff51bf2bf
Signed-off-by: Christina Warren <cawarren@ti.com>

6 files changed, 173 insertions, 0 deletions

diff --git a/arch/arm/mach-omap2/board-4430sdp.c b/arch/arm/mach-omap2/board-4430sdp.c
index 375b595..cf479a0 100644
--- a/arch/arm/mach-omap2/board-4430sdp.c
+++ b/arch/arm/mach-omap2/board-4430sdp.c
@@ -19,6 +19,7 @@
 #include <linux/gpio.h>
 #include <linux/usb/otg.h>
 #include <linux/spi/spi.h>
+#include <linux/hwspinlock.h>
 #include <linux/i2c/twl.h>
 #include <linux/gpio_keys.h>
 #include <linux/regulator/machine.h>
@@ -782,8 +783,42 @@ static void __init blaze_pmic_mux_init(void)
 						OMAP_WAKEUP_EN);
 }
 
+static void __init omap_i2c_hwspinlock_init(int bus_id, int spinlock_id,
+				struct omap_i2c_bus_board_data *pdata)
+{
+	/* spinlock_id should be -1 for a generic lock request */
+	if (spinlock_id < 0)
+		pdata->handle = hwspin_lock_request();
+	else
+		pdata->handle = hwspin_lock_request_specific(spinlock_id);
+
+	if (pdata->handle != NULL) {
+		pdata->hwspin_lock_timeout = hwspin_lock_timeout;
+		pdata->hwspin_unlock = hwspin_unlock;
+	} else {
+		pr_err("I2C hwspinlock request failed for bus %d\n", \
+								bus_id);
+	}
+}
+
+static struct omap_i2c_bus_board_data __initdata sdp4430_i2c_1_bus_pdata;
+static struct omap_i2c_bus_board_data __initdata sdp4430_i2c_2_bus_pdata;
+static struct omap_i2c_bus_board_data __initdata sdp4430_i2c_3_bus_pdata;
+static struct omap_i2c_bus_board_data __initdata sdp4430_i2c_4_bus_pdata;
+
 static int __init omap4_i2c_init(void)
 {
+
+	omap_i2c_hwspinlock_init(1, 0, &sdp4430_i2c_1_bus_pdata);
+	omap_i2c_hwspinlock_init(2, 1, &sdp4430_i2c_2_bus_pdata);
+	omap_i2c_hwspinlock_init(3, 2, &sdp4430_i2c_3_bus_pdata);
+	omap_i2c_hwspinlock_init(4, 3, &sdp4430_i2c_4_bus_pdata);
+
+	omap_register_i2c_bus_board_data(1, &sdp4430_i2c_1_bus_pdata);
+	omap_register_i2c_bus_board_data(2, &sdp4430_i2c_2_bus_pdata);
+	omap_register_i2c_bus_board_data(3, &sdp4430_i2c_3_bus_pdata);
+	omap_register_i2c_bus_board_data(4, &sdp4430_i2c_4_bus_pdata);
+
 	omap4_pmic_init("twl6030", &sdp4430_twldata);
 	omap_register_i2c_bus(2, 400, NULL, 0);
 	omap_register_i2c_bus(3, 400, sdp4430_i2c_3_boardinfo,
diff --git a/arch/arm/mach-omap2/board-44xx-tablet.c b/arch/arm/mach-omap2/board-44xx-tablet.c
index d9886e5..91b5f8d 100644
--- a/arch/arm/mach-omap2/board-44xx-tablet.c
+++ b/arch/arm/mach-omap2/board-44xx-tablet.c
@@ -21,6 +21,7 @@
 #include <linux/reboot.h>
 #include <linux/usb/otg.h>
 #include <linux/spi/spi.h>
+#include <linux/hwspinlock.h>
 #include <linux/i2c/twl.h>
 #include <linux/twl6040-vib.h>
 #include <linux/regulator/machine.h>
@@ -523,8 +524,41 @@ static void __init tablet_pmic_mux_init(void)
 						OMAP_WAKEUP_EN);
 }
 
+static void __init omap_i2c_hwspinlock_init(int bus_id, int spinlock_id,
+				struct omap_i2c_bus_board_data *pdata)
+{
+	/* spinlock_id should be -1 for a generic lock request */
+	if (spinlock_id < 0)
+		pdata->handle = hwspin_lock_request();
+	else
+		pdata->handle = hwspin_lock_request_specific(spinlock_id);
+
+	if (pdata->handle != NULL) {
+		pdata->hwspin_lock_timeout = hwspin_lock_timeout;
+		pdata->hwspin_unlock = hwspin_unlock;
+	} else {
+		pr_err("I2C hwspinlock request failed for bus %d\n", \
+								bus_id);
+	}
+}
+
+static struct omap_i2c_bus_board_data __initdata sdp4430_i2c_1_bus_pdata;
+static struct omap_i2c_bus_board_data __initdata sdp4430_i2c_2_bus_pdata;
+static struct omap_i2c_bus_board_data __initdata sdp4430_i2c_3_bus_pdata;
+static struct omap_i2c_bus_board_data __initdata sdp4430_i2c_4_bus_pdata;
+
 static int __init omap4_i2c_init(void)
 {
+	omap_i2c_hwspinlock_init(1, 0, &sdp4430_i2c_1_bus_pdata);
+	omap_i2c_hwspinlock_init(2, 1, &sdp4430_i2c_2_bus_pdata);
+	omap_i2c_hwspinlock_init(3, 2, &sdp4430_i2c_3_bus_pdata);
+	omap_i2c_hwspinlock_init(4, 3, &sdp4430_i2c_4_bus_pdata);
+
+	omap_register_i2c_bus_board_data(1, &sdp4430_i2c_1_bus_pdata);
+	omap_register_i2c_bus_board_data(2, &sdp4430_i2c_2_bus_pdata);
+	omap_register_i2c_bus_board_data(3, &sdp4430_i2c_3_bus_pdata);
+	omap_register_i2c_bus_board_data(4, &sdp4430_i2c_4_bus_pdata);
+
 	omap4_pmic_init("twl6030", &tablet_twldata);
 	omap_register_i2c_bus(2, 400, NULL, 0);
 	omap_register_i2c_bus(3, 400, tablet_i2c_3_boardinfo,
diff --git a/arch/arm/plat-omap/i2c.c b/arch/arm/plat-omap/i2c.c
index f8dc82f..0e8c407 100644
--- a/arch/arm/plat-omap/i2c.c
+++ b/arch/arm/plat-omap/i2c.c
@@ -250,3 +250,44 @@ int __init omap_register_i2c_bus(int bus_id, u32 clkrate,
 
 	return omap_i2c_add_bus(bus_id);
 }
+
+/**
+ * omap_register_i2c_bus_board_data - register hwspinlock data
+ * @bus_id: bus id counting from number 1
+ * @pdata: pointer to the I2C bus board data
+ */
+void omap_register_i2c_bus_board_data(int bus_id,
+				struct omap_i2c_bus_board_data *pdata)
+{
+	BUG_ON(bus_id < 1 || bus_id > omap_i2c_nr_ports());
+
+	if ((pdata != NULL) && (pdata->handle != NULL)) {
+		i2c_pdata[bus_id - 1].handle = pdata->handle;
+		i2c_pdata[bus_id - 1].hwspin_lock_timeout =
+					pdata->hwspin_lock_timeout;
+		i2c_pdata[bus_id - 1].hwspin_unlock = pdata->hwspin_unlock;
+	}
+}
+
+/**
+ * omap_i2c_get_hwspinlockid - Get HWSPINLOCK ID for I2C device
+ * @dev: I2C device
+ *
+ * returns the hwspinlock id or -1 if does not exist
+ */
+int omap_i2c_get_hwspinlockid(struct device *dev)
+{
+	struct omap_i2c_bus_platform_data *pdata;
+
+	pdata = dev_get_platdata(dev);
+	if (!pdata) {
+		dev_err(dev, "%s: platform data is missing\n", __func__);
+		return -EINVAL;
+	}
+
+	if (pdata->handle != NULL)
+		return hwspin_lock_get_id(pdata->handle);
+	else
+		return -1;
+}
+EXPORT_SYMBOL_GPL(omap_i2c_get_hwspinlockid);
diff --git a/arch/arm/plat-omap/include/plat/i2c.h b/arch/arm/plat-omap/include/plat/i2c.h
index 878d632..2f7164b 100644
--- a/arch/arm/plat-omap/include/plat/i2c.h
+++ b/arch/arm/plat-omap/include/plat/i2c.h
@@ -22,6 +22,29 @@
 #define __ASM__ARCH_OMAP_I2C_H
 
 #include <linux/i2c.h>
+#include <linux/hwspinlock.h>
+
+struct omap_i2c_bus_board_data {
+	struct hwspinlock *handle;
+	int (*hwspin_lock_timeout)(struct hwspinlock *hwlock, unsigned int to);
+	void (*hwspin_unlock)(struct hwspinlock *hwlock);
+};
+
+/**
+ * omap_register_i2c_bus_board_data - register hwspinlock data
+ * @bus_id: bus id counting from number 1
+ * @pdata: pointer to the I2C bus board data
+ */
+void omap_register_i2c_bus_board_data(int bus_id,
+				struct omap_i2c_bus_board_data *pdata);
+
+/**
+ * omap_i2c_get_hwspinlockid - Get HWSPINLOCK ID for I2C device
+ * @dev: I2C device
+ *
+ * returns the hwspinlock id or -1 if does not exist
+ */
+int omap_i2c_get_hwspinlockid(struct device *dev);
 
 #if defined(CONFIG_I2C_OMAP) || defined(CONFIG_I2C_OMAP_MODULE)
 extern int omap_register_i2c_bus(int bus_id, u32 clkrate,
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 85abf9a..eec68f9 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -38,6 +38,7 @@
 #include <linux/clk.h>
 #include <linux/io.h>
 #include <linux/slab.h>
+#include <linux/hwspinlock.h>
 #include <linux/i2c-omap.h>
 #include <linux/pm_runtime.h>
 #include <linux/pm_qos_params.h>
@@ -266,6 +267,31 @@ static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *i2c_dev, int reg)
 				(i2c_dev->regs[reg] << i2c_dev->reg_shift));
 }
 
+static int omap_i2c_hwspinlock_lock(struct omap_i2c_dev *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev->dev);
+	struct omap_i2c_bus_platform_data *pdata = pdev->dev.platform_data;
+	int ret = 0;
+
+	if (pdata->hwspin_lock_timeout) {
+		ret = pdata->hwspin_lock_timeout(pdata->handle, 100);
+		if (ret != 0)
+			dev_err(&pdev->dev, "%s: TIMEDOUT: Failed to acquire "
+						"hwspinlock\n", __func__);
+		return ret;
+	} else
+		return -EINVAL;
+}
+
+static void omap_i2c_hwspinlock_unlock(struct omap_i2c_dev *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev->dev);
+	struct omap_i2c_bus_platform_data *pdata = pdev->dev.platform_data;
+
+	if (pdata->hwspin_unlock)
+		pdata->hwspin_unlock(pdata->handle);
+}
+
 static void omap_i2c_unidle(struct omap_i2c_dev *dev)
 {
 	struct platform_device *pdev;
@@ -631,6 +657,15 @@ omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 	int i;
 	int r;
 
+	if (dev == NULL)
+		return -EINVAL;
+
+	r = omap_i2c_hwspinlock_lock(dev);
+	/* To-Do: if we are unable to acquire the lock, we must
+	try to recover somehow */
+	if (r != 0)
+		return r;
+
 	omap_i2c_unidle(dev);
 
 	r = omap_i2c_wait_for_bb(dev);
@@ -661,6 +696,7 @@ omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 	omap_i2c_wait_for_bb(dev);
 out:
 	omap_i2c_idle(dev);
+	omap_i2c_hwspinlock_unlock(dev);
 	return r;
 }
 
diff --git a/include/linux/i2c-omap.h b/include/linux/i2c-omap.h
index 3beb390..3ac6cc2 100644
--- a/include/linux/i2c-omap.h
+++ b/include/linux/i2c-omap.h
@@ -9,6 +9,10 @@ struct omap_i2c_bus_platform_data {
 	int		(*device_enable) (struct platform_device *pdev);
 	int		(*device_shutdown) (struct platform_device *pdev);
 	int		(*device_idle) (struct platform_device *pdev);
+	struct		hwspinlock *handle;
+	int		(*hwspin_lock_timeout)(struct hwspinlock *hwlock,
+							unsigned int to);
+	void		(*hwspin_unlock)(struct hwspinlock *hwlock);
 };
 
 #endif