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authorMarcin Tomczak <marcin.tomczak@intel.com>2012-01-27 11:14:50 -0800
committerJames Bottomley <JBottomley@Parallels.com>2012-02-19 08:09:00 -0600
commite5cc6aa4b6ef34c3f054af8c61a4f73c157589c3 (patch)
tree64efa1d1dbece4ce058e7cd19b205bde9ef5bdc1
parente3d338a536330b5ffc9f28d7c6a4cdf6ba51867a (diff)
downloadlinux-e5cc6aa4b6ef34c3f054af8c61a4f73c157589c3.tar.gz
linux-e5cc6aa4b6ef34c3f054af8c61a4f73c157589c3.tar.xz
[SCSI] isci: enable clock gating
Enabling clock gating for power savings on entry to controller ready state. Disable SCU clock gating for power savings on exit from the controller ready state. The gating is fully automated by silicon after setting the mode. Signed-off-by: Marcin Tomczak <marcin.tomczak@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
-rw-r--r--drivers/scsi/isci/host.c9
-rw-r--r--drivers/scsi/isci/registers.h27
2 files changed, 34 insertions, 2 deletions
diff --git a/drivers/scsi/isci/host.c b/drivers/scsi/isci/host.c
index 418391b1c361..508aa8ce25b4 100644
--- a/drivers/scsi/isci/host.c
+++ b/drivers/scsi/isci/host.c
@@ -1491,6 +1491,15 @@ sci_controller_set_interrupt_coalescence(struct isci_host *ihost,
static void sci_controller_ready_state_enter(struct sci_base_state_machine *sm)
{
struct isci_host *ihost = container_of(sm, typeof(*ihost), sm);
+ u32 val;
+
+ /* enable clock gating for power control of the scu unit */
+ val = readl(&ihost->smu_registers->clock_gating_control);
+ val &= ~(SMU_CGUCR_GEN_BIT(REGCLK_ENABLE) |
+ SMU_CGUCR_GEN_BIT(TXCLK_ENABLE) |
+ SMU_CGUCR_GEN_BIT(XCLK_ENABLE));
+ val |= SMU_CGUCR_GEN_BIT(IDLE_ENABLE);
+ writel(val, &ihost->smu_registers->clock_gating_control);
/* set the default interrupt coalescence number and timeout value. */
sci_controller_set_interrupt_coalescence(ihost, 0, 0);
diff --git a/drivers/scsi/isci/registers.h b/drivers/scsi/isci/registers.h
index eaa541afc755..7eb0ccd45fe6 100644
--- a/drivers/scsi/isci/registers.h
+++ b/drivers/scsi/isci/registers.h
@@ -370,6 +370,27 @@ struct scu_iit_entry {
>> SMU_DEVICE_CONTEXT_CAPACITY_MAX_RNC_SHIFT \
)
+/* ***************************************************************************** */
+#define SMU_CLOCK_GATING_CONTROL_IDLE_ENABLE_SHIFT (0)
+#define SMU_CLOCK_GATING_CONTROL_IDLE_ENABLE_MASK (0x00000001)
+#define SMU_CLOCK_GATING_CONTROL_XCLK_ENABLE_SHIFT (1)
+#define SMU_CLOCK_GATING_CONTROL_XCLK_ENABLE_MASK (0x00000002)
+#define SMU_CLOCK_GATING_CONTROL_TXCLK_ENABLE_SHIFT (2)
+#define SMU_CLOCK_GATING_CONTROL_TXCLK_ENABLE_MASK (0x00000004)
+#define SMU_CLOCK_GATING_CONTROL_REGCLK_ENABLE_SHIFT (3)
+#define SMU_CLOCK_GATING_CONTROL_REGCLK_ENABLE_MASK (0x00000008)
+#define SMU_CLOCK_GATING_CONTROL_IDLE_TIMEOUT_SHIFT (16)
+#define SMU_CLOCK_GATING_CONTROL_IDLE_TIMEOUT_MASK (0x000F0000)
+#define SMU_CLOCK_GATING_CONTROL_FORCE_IDLE_SHIFT (31)
+#define SMU_CLOCK_GATING_CONTROL_FORCE_IDLE_MASK (0x80000000)
+#define SMU_CLOCK_GATING_CONTROL_RESERVED_MASK (0x7FF0FFF0)
+
+#define SMU_CGUCR_GEN_VAL(name, value) \
+ SCU_GEN_VALUE(SMU_CLOCK_GATING_CONTROL_##name, value)
+
+#define SMU_CGUCR_GEN_BIT(name) \
+ SCU_GEN_BIT(SMU_CLOCK_GATING_CONTROL_##name)
+
/* -------------------------------------------------------------------------- */
#define SMU_CONTROL_STATUS_TASK_CONTEXT_RANGE_ENABLE_SHIFT (0)
@@ -992,8 +1013,10 @@ struct smu_registers {
u32 mmr_address_window;
/* 0x00A4 SMDW */
u32 mmr_data_window;
- u32 reserved_A8;
- u32 reserved_AC;
+/* 0x00A8 CGUCR */
+ u32 clock_gating_control;
+/* 0x00AC CGUPC */
+ u32 clock_gating_performance;
/* A whole bunch of reserved space */
u32 reserved_Bx[4];
u32 reserved_Cx[4];