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Subject[PATCH 3/3] ipc: Added support for IPC interrupt mode
Date
From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>

This patch adds support for ipc command interrupt mode.

Also added following access mode config options.

CONFIG_INTEL_SCU_IPC_INTR_MODE - Selecting this option
will configure the driver to receive IOC interrupt for
each successful ipc_command.

CONFIG_INTEL_SCU_IPC_POLL_MODE - Makes driver use
polling method to track the command completion status.

Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Cc: David Cohen <david.a.cohen@linux.intel.com>
---
drivers/platform/x86/Kconfig | 23 ++++++++++++++++
drivers/platform/x86/intel_scu_ipc.c | 53 ++++++++++++++++++++++++++++++++++--
2 files changed, 73 insertions(+), 3 deletions(-)

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index b51a7460cc49..ade424c68eee 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -655,6 +655,29 @@ config INTEL_SCU_IPC
some embedded Intel x86 platforms. This is not needed for PC-type
machines.

+choice
+ prompt "IPC access mode"
+ depends on INTEL_SCU_IPC
+ default INTEL_SCU_IPC_INTR_MODE
+ ---help---
+ Select the desired access mode for IPC call.
+
+config INTEL_SCU_IPC_INTR_MODE
+ bool "Intel SCU IPC interrupt mode"
+ ---help---
+ Selecting this option will configure the driver
+ to receive IOC interrupt for each successful
+ ipc_command.
+
+
+config INTEL_SCU_IPC_POLL_MODE
+ bool "Intel SCU IPC polling mode"
+ ---help---
+ Makes driver use polling method to track the
+ command completion status
+
+endchoice
+
config INTEL_SCU_IPC_UTIL
tristate "Intel SCU IPC utility driver"
depends on INTEL_SCU_IPC
diff --git a/drivers/platform/x86/intel_scu_ipc.c b/drivers/platform/x86/intel_scu_ipc.c
index 4851560c88fe..52327dd12018 100644
--- a/drivers/platform/x86/intel_scu_ipc.c
+++ b/drivers/platform/x86/intel_scu_ipc.c
@@ -60,6 +60,7 @@

#define IPC_WWBUF_SIZE 20 /* IPC Write buffer Size */
#define IPC_RWBUF_SIZE 20 /* IPC Read buffer Size */
+#define IPC_IOC 0x100 /* IPC command register IOC bit */

enum {
SCU_IPC_LINCROFT,
@@ -110,6 +111,9 @@ struct intel_scu_ipc_dev {
struct pci_dev *pdev;
void __iomem *ipc_base;
void __iomem *i2c_base;
+#ifdef CONFIG_INTEL_SCU_IPC_INTR_MODE
+ struct completion cmd_complete;
+#endif
};

static struct intel_scu_ipc_dev ipcdev; /* Only one for now */
@@ -136,7 +140,12 @@ static DEFINE_MUTEX(ipclock); /* lock used to prevent multiple call to SCU */
*/
static inline void ipc_command(u32 cmd) /* Send ipc command */
{
+#ifdef CONFIG_INTEL_SCU_IPC_INTR_MODE
+ INIT_COMPLETION(ipcdev.cmd_complete);
+ writel(cmd | IPC_IOC, ipcdev.ipc_base);
+#else
writel(cmd, ipcdev.ipc_base);
+#endif
}

/*
@@ -194,6 +203,37 @@ static inline int busy_loop(void) /* Wait till scu status is busy */
return 0;
}

+#ifdef CONFIG_INTEL_SCU_IPC_INTR_MODE
+/* Wait till ipc ioc interrupt is received or timeout in 3 HZ */
+static inline int ipc_wait_for_interrupt(void)
+{
+ int status;
+ int ret = 0;
+
+ if (!wait_for_completion_timeout(&ipcdev.cmd_complete, 3 * HZ)) {
+ ret = -ETIMEDOUT;
+ goto end;
+ }
+
+ status = ipc_read_status();
+
+ if ((status >> 1) & 1)
+ ret = -EIO;
+
+end:
+ return ret;
+}
+#endif
+
+int intel_scu_ipc_check_status(void)
+{
+#ifdef CONFIG_INTEL_SCU_IPC_INTR_MODE
+ return ipc_wait_for_interrupt();
+#else
+ return busy_loop();
+#endif
+}
+
/* Read/Write power control(PMIC in Langwell, MSIC in PenWell) registers */
static int pwr_reg_rdwr(u16 *addr, u8 *data, u32 count, u32 op, u32 id)
{
@@ -234,7 +274,7 @@ static int pwr_reg_rdwr(u16 *addr, u8 *data, u32 count, u32 op, u32 id)
ipc_command(4 << 16 | id << 12 | 0 << 8 | op);
}

- err = busy_loop();
+ err = intel_scu_ipc_check_status();
if (id == IPC_CMD_PCNTRL_R) { /* Read rbuf */
/* Workaround: values are read as 0 without memcpy_fromio */
memcpy_fromio(cbuf, ipcdev.ipc_base + 0x90, 16);
@@ -429,7 +469,7 @@ int intel_scu_ipc_simple_command(int cmd, int sub)
return -ENODEV;
}
ipc_command(sub << 12 | cmd);
- err = busy_loop();
+ err = intel_scu_ipc_check_status();
mutex_unlock(&ipclock);
return err;
}
@@ -463,7 +503,7 @@ int intel_scu_ipc_command(int cmd, int sub, u32 *in, int inlen,
ipc_data_writel(*in++, 4 * i);

ipc_command((inlen << 16) | (sub << 12) | cmd);
- err = busy_loop();
+ err = intel_scu_ipc_check_status();

for (i = 0; i < outlen; i++)
*out++ = ipc_data_readl(4 * i);
@@ -529,6 +569,9 @@ EXPORT_SYMBOL(intel_scu_ipc_i2c_cntrl);
*/
static irqreturn_t ioc(int irq, void *dev_id)
{
+#ifdef CONFIG_INTEL_SCU_IPC_INTR_MODE
+ complete(&ipcdev.cmd_complete);
+#endif
return IRQ_HANDLED;
}

@@ -566,6 +609,10 @@ static int ipc_probe(struct pci_dev *dev, const struct pci_device_id *id)
if (!pci_resource)
return -ENOMEM;

+#ifdef CONFIG_INTEL_SCU_IPC_INTR_MODE
+ init_completion(&ipcdev.cmd_complete);
+#endif
+
if (request_irq(dev->irq, ioc, 0, "intel_scu_ipc", &ipcdev))
return -EBUSY;

--
1.8.4.2


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