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Message-Id: <1384561314-11210-1-git-send-email-david.a.cohen@linux.intel.com>
Date: Fri, 15 Nov 2013 16:21:54 -0800
From: David Cohen <david.a.cohen@...ux.intel.com>
To: matthew.garrett@...ula.com
Cc: platform-driver-x86@...r.kernel.org, linux-kernel@...r.kernel.org,
gnomes@...rguk.ukuu.org.uk,
sathyanarayanan.kuppuswamy@...ux.intel.com,
eric.ernst@...ux.intel.com,
David Cohen <david.a.cohen@...ux.intel.com>
Subject: [PATCH v2.1] ipc: Added support for IPC interrupt mode
From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@...ux.intel.com>
This patch adds support for ipc command interrupt mode.
Also added platform data option to select 'irq_mode'
irq_mode = 1: configure the driver to receive IOC interrupt
for each successful ipc_command.
irq_mode = 0: makes driver use polling method to
track the command completion status.
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@...ux.intel.com>
Signed-off-by: David Cohen <david.a.cohen@...ux.intel.com>
---
v2 to v2.1:
- IRQ mode is not stable on Tangier. This new version disables it for such
platform.
---
drivers/platform/x86/intel_scu_ipc.c | 48 +++++++++++++++++++++++++++++++++---
1 file changed, 45 insertions(+), 3 deletions(-)
diff --git a/drivers/platform/x86/intel_scu_ipc.c b/drivers/platform/x86/intel_scu_ipc.c
index e26830f6c8dd..287a55062dc6 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,
@@ -74,6 +75,7 @@ struct intel_scu_ipc_pdata_t {
u32 i2c_base;
u32 ipc_len;
u32 i2c_len;
+ u8 irq_mode;
};
static struct intel_scu_ipc_pdata_t intel_scu_ipc_pdata[] = {
@@ -82,24 +84,28 @@ static struct intel_scu_ipc_pdata_t intel_scu_ipc_pdata[] = {
.i2c_base = 0xff12b000,
.ipc_len = 0x100,
.i2c_len = 0x10,
+ .irq_mode = 0,
},
[SCU_IPC_PENWELL] = {
.ipc_base = 0xff11c000,
.i2c_base = 0xff12b000,
.ipc_len = 0x100,
.i2c_len = 0x10,
+ .irq_mode = 1,
},
[SCU_IPC_CLOVERVIEW] = {
.ipc_base = 0xff11c000,
.i2c_base = 0xff12b000,
.ipc_len = 0x100,
.i2c_len = 0x10,
+ .irq_mode = 1,
},
[SCU_IPC_TANGIER] = {
.ipc_base = 0xff009000,
.i2c_base = 0xff00d000,
.ipc_len = 0x100,
.i2c_len = 0x10,
+ .irq_mode = 0,
},
};
@@ -110,6 +116,8 @@ struct intel_scu_ipc_dev {
struct pci_dev *pdev;
void __iomem *ipc_base;
void __iomem *i2c_base;
+ struct completion cmd_complete;
+ u8 irq_mode;
};
static struct intel_scu_ipc_dev ipcdev; /* Only one for now */
@@ -136,6 +144,10 @@ static DEFINE_MUTEX(ipclock); /* lock used to prevent multiple call to SCU */
*/
static inline void ipc_command(u32 cmd) /* Send ipc command */
{
+ if (ipcdev.irq_mode) {
+ INIT_COMPLETION(ipcdev.cmd_complete);
+ writel(cmd | IPC_IOC, ipcdev.ipc_base);
+ }
writel(cmd, ipcdev.ipc_base);
}
@@ -194,6 +206,30 @@ static inline int busy_loop(void) /* Wait till scu status is busy */
return 0;
}
+/* Wait till ipc ioc interrupt is received or timeout in 3 HZ */
+static inline int ipc_wait_for_interrupt(void)
+{
+ int status;
+
+ if (!wait_for_completion_timeout(&ipcdev.cmd_complete, 3 * HZ)) {
+ struct device *dev = &ipcdev.pdev->dev;
+ dev_err(dev, "IPC timed out\n");
+ return -ETIMEDOUT;
+ }
+
+ status = ipc_read_status();
+
+ if ((status >> 1) & 1)
+ return -EIO;
+
+ return 0;
+}
+
+int intel_scu_ipc_check_status(void)
+{
+ return ipcdev.irq_mode ? ipc_wait_for_interrupt() : busy_loop();
+}
+
/* 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 +270,7 @@ 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 (!err && 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 +465,7 @@ 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 +499,7 @@ 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();
if (!err) {
for (i = 0; i < outlen; i++)
@@ -531,6 +567,9 @@ EXPORT_SYMBOL(intel_scu_ipc_i2c_cntrl);
*/
static irqreturn_t ioc(int irq, void *dev_id)
{
+ if (ipcdev.irq_mode)
+ complete(&ipcdev.cmd_complete);
+
return IRQ_HANDLED;
}
@@ -555,6 +594,7 @@ static int ipc_probe(struct pci_dev *dev, const struct pci_device_id *id)
pdata = &intel_scu_ipc_pdata[pid];
ipcdev.pdev = pci_dev_get(dev);
+ ipcdev.irq_mode = pdata->irq_mode;
err = pci_enable_device(dev);
if (err)
@@ -568,6 +608,8 @@ static int ipc_probe(struct pci_dev *dev, const struct pci_device_id *id)
if (!pci_resource)
return -ENOMEM;
+ init_completion(&ipcdev.cmd_complete);
+
if (request_irq(dev->irq, ioc, 0, "intel_scu_ipc", &ipcdev))
return -EBUSY;
--
1.8.4.2
--
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