From 237454b288960eb5120ca26529084a59a6b96b9a Mon Sep 17 00:00:00 2001
From: Alex Van Damme <atv@google.com>
Date: Mon, 23 Jul 2018 16:06:02 -0700
Subject: [PATCH] Apex performance ioctl

Change-Id: Id3ae759f748b3f8c6f6a5320a5088c43fad0e812
---
 apex.h        | 15 +++++++++++
 apex_driver.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 85 insertions(+)

diff --git a/apex.h b/apex.h
index 4ef2641..7279589 100644
--- a/apex.h
+++ b/apex.h
@@ -77,6 +77,19 @@ struct apex_gate_clock_ioctl {
 	u64 force_idle;
 };
 
+/* Performance expectation ioctl. */
+enum apex_performance_expectation {
+        APEX_PERFORMANCE_LOW = 0,
+        APEX_PERFORMANCE_MED = 1,
+        APEX_PERFORMANCE_HIGH = 2,
+        APEX_PERFORMANCE_MAX = 3,
+};
+
+struct apex_performance_expectation_ioctl {
+        /* Expected performance from apex. */
+        uint32_t performance;
+};
+
 /* Base number for all Apex-common IOCTLs */
 #define APEX_IOCTL_BASE 0x7F
 
@@ -84,4 +97,6 @@ struct apex_gate_clock_ioctl {
 #define APEX_IOCTL_GATE_CLOCK                                                  \
 	_IOW(APEX_IOCTL_BASE, 0, struct apex_gate_clock_ioctl)
 
+#define APEX_IOCTL_PERFORMANCE_EXPECTATION _IOW(APEX_IOCTL_BASE, 1, struct apex_performance_expectation_ioctl)
+
 #endif /* __APEX_H__ */
diff --git a/apex_driver.c b/apex_driver.c
index 3a83c3d..b25f763 100644
--- a/apex_driver.c
+++ b/apex_driver.c
@@ -146,6 +146,8 @@ static long apex_ioctl(struct file *file, uint cmd, ulong arg);
 
 static long apex_clock_gating(struct gasket_dev *gasket_dev, ulong arg);
 
+static long apex_set_performance_expectation(struct gasket_dev *gasket_dev, ulong arg);
+
 static int apex_enter_reset(struct gasket_dev *gasket_dev, uint type);
 
 static int apex_quit_reset(struct gasket_dev *gasket_dev, uint type);
@@ -652,6 +654,8 @@ static long apex_ioctl(struct file *filp, uint cmd, ulong arg)
 	switch (cmd) {
 	case APEX_IOCTL_GATE_CLOCK:
 		return apex_clock_gating(gasket_dev, arg);
+	case APEX_IOCTL_PERFORMANCE_EXPECTATION:
+		return apex_set_performance_expectation(gasket_dev, arg);
 	default:
 		return -ENOTTY; /* unknown command */
 	}
@@ -697,6 +701,72 @@ static long apex_clock_gating(struct gasket_dev *gasket_dev, ulong arg)
 	return 0;
 }
 
+/*
+ * apex_set_performance_expectation: Adjust clock rates for Apex.
+ * @gasket_dev: device pointer.
+ * @arg: User ioctl arg, in this case to an apex_performance_expectation_ioctl struct.
+ */
+static long apex_set_performance_expectation(struct gasket_dev *gasket_dev, ulong arg)
+{
+	struct apex_performance_expectation_ioctl ibuf;
+	uint32_t rg_gcb_clk_div = 0;
+	uint32_t rg_axi_clk_125m = 0;
+        const int AXI_CLK_125M_SHIFT = 2;
+        const int MCU_CLK_250M_SHIFT = 3;
+
+	// 8051 clock is always 250 MHz for PCIe, as it's not used at all.
+	const uint32_t rg_8051_clk_250m = 1;
+
+	if (bypass_top_level)
+		return 0;
+
+	if (copy_from_user(&ibuf, (void __user *)arg, sizeof(ibuf)))
+		return -EFAULT;
+
+	switch (ibuf.performance) {
+		case APEX_PERFORMANCE_LOW:
+			// - GCB clock: 62.5 MHz
+			// - AXI clock: 125 MHz
+			rg_gcb_clk_div = 3;
+			rg_axi_clk_125m = 0;
+			break;
+
+		case APEX_PERFORMANCE_MED:
+			// - GCB clock: 125 MHz
+			// - AXI clock: 125 MHz
+			rg_gcb_clk_div = 2;
+			rg_axi_clk_125m = 0;
+			break;
+
+		case APEX_PERFORMANCE_HIGH:
+			// - GCB clock: 250 MHz
+			// - AXI clock: 125 MHz
+			rg_gcb_clk_div = 1;
+			rg_axi_clk_125m = 0;
+			break;
+
+		case APEX_PERFORMANCE_MAX:
+			// - GCB clock: 500 MHz
+			// - AXI clock: 125 MHz
+			rg_gcb_clk_div = 0;
+			rg_axi_clk_125m = 0;
+			break;
+
+		default:
+			return -EINVAL;
+	}
+
+	/*
+	 * Set clock rates for GCB, AXI, and 8051:
+	 */
+	gasket_read_modify_write_32(
+		gasket_dev, APEX_BAR_INDEX, APEX_BAR2_REG_SCU_3,
+                (rg_gcb_clk_div | (rg_axi_clk_125m << AXI_CLK_125M_SHIFT) | (rg_8051_clk_250m << MCU_CLK_250M_SHIFT)),
+                /*mask_width=*/4, /*mask_shift=*/28);
+
+	return 0;
+}
+
 /*
  * Display driver sysfs entries.
  * @device: Kernel device structure.