diff mbox series

[v6,093/102] x86: apl: Add PUNIT driver

Message ID 20191207044315.51770-9-sjg@chromium.org
State Superseded
Delegated to: Bin Meng
Headers show
Series x86: Add initial support for apollolake | expand

Commit Message

Simon Glass Dec. 7, 2019, 4:43 a.m. UTC 
Add a driver for the Apollo Lake P-unit (power unit). It is modelled as a
syscon driver since it only needs to be probed.

Signed-off-by: Simon Glass <sjg@chromium.org>
---

Changes in v6:
- Drop Glacier Lake code
- Drop platform data and pre-PCI code, since DM PCI is available in SPL

Changes in v5: None
Changes in v4:
- Name this P-Unit instead of power unit, in the commit message
- apollolake -> Apollo Lake

Changes in v3:
- Use pci_get_devfn()

Changes in v2: None

 arch/x86/cpu/apollolake/Makefile |  3 +
 arch/x86/cpu/apollolake/punit.c  | 94 ++++++++++++++++++++++++++++++++
 2 files changed, 97 insertions(+)
 create mode 100644 arch/x86/cpu/apollolake/punit.c

Comments

Bin Meng Dec. 8, 2019, 8:26 a.m. UTC | #1 
On Sat, Dec 7, 2019 at 12:54 PM Simon Glass <sjg@chromium.org> wrote:
>
> Add a driver for the Apollo Lake P-unit (power unit). It is modelled as a
> syscon driver since it only needs to be probed.
>
> Signed-off-by: Simon Glass <sjg@chromium.org>
> ---
>
> Changes in v6:
> - Drop Glacier Lake code
> - Drop platform data and pre-PCI code, since DM PCI is available in SPL
>
> Changes in v5: None
> Changes in v4:
> - Name this P-Unit instead of power unit, in the commit message
> - apollolake -> Apollo Lake
>
> Changes in v3:
> - Use pci_get_devfn()
>
> Changes in v2: None
>
>  arch/x86/cpu/apollolake/Makefile |  3 +
>  arch/x86/cpu/apollolake/punit.c  | 94 ++++++++++++++++++++++++++++++++
>  2 files changed, 97 insertions(+)
>  create mode 100644 arch/x86/cpu/apollolake/punit.c
>

Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff mbox series

Patch

diff --git a/arch/x86/cpu/apollolake/Makefile b/arch/x86/cpu/apollolake/Makefile
index 36eefcbad7..875d454157 100644
--- a/arch/x86/cpu/apollolake/Makefile
+++ b/arch/x86/cpu/apollolake/Makefile
@@ -3,6 +3,9 @@ 
 # Copyright 2019 Google LLC
 
 obj-$(CONFIG_SPL_BUILD) += systemagent.o
+ifndef CONFIG_TPL_BUILD
+obj-y += punit.o
+endif
 
 obj-y += hostbridge.o
 obj-y += itss.o
diff --git a/arch/x86/cpu/apollolake/punit.c b/arch/x86/cpu/apollolake/punit.c
new file mode 100644
index 0000000000..1a131fb0b1
--- /dev/null
+++ b/arch/x86/cpu/apollolake/punit.c
@@ -0,0 +1,94 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 Google LLC
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <spl.h>
+#include <asm/cpu.h>
+#include <asm/cpu_common.h>
+#include <asm/intel_regs.h>
+#include <asm/io.h>
+#include <asm/pci.h>
+#include <asm/arch/systemagent.h>
+
+/*
+ * Punit Initialisation code. This all isn't documented, but
+ * this is the recipe.
+ */
+static int punit_init(struct udevice *dev)
+{
+	struct udevice *cpu;
+	u32 reg;
+	ulong start;
+	int ret;
+
+	/* Thermal throttle activation offset */
+	ret = uclass_first_device_err(UCLASS_CPU, &cpu);
+	if (ret)
+		return log_msg_ret("Cannot find CPU", ret);
+	cpu_configure_thermal_target(cpu);
+
+	/*
+	 * Software Core Disable Mask (P_CR_CORE_DISABLE_MASK_0_0_0_MCHBAR).
+	 * Enable all cores here.
+	 */
+	writel(0, MCHBAR_REG(CORE_DISABLE_MASK));
+
+	/* P-Unit bring up */
+	reg = readl(MCHBAR_REG(BIOS_RESET_CPL));
+	if (reg == 0xffffffff) {
+		/* P-unit not found */
+		debug("Punit MMIO not available\n");
+		return -ENOENT;
+	}
+
+	/* Set Punit interrupt pin IPIN offset 3D */
+	dm_pci_write_config8(dev, PCI_INTERRUPT_PIN, 0x2);
+
+	/* Set PUINT IRQ to 24 and INTPIN LOCK */
+	writel(PUINT_THERMAL_DEVICE_IRQ_VEC_NUMBER |
+	       PUINT_THERMAL_DEVICE_IRQ_LOCK,
+	       MCHBAR_REG(PUNIT_THERMAL_DEVICE_IRQ));
+
+	/* Stage0 BIOS Reset Complete (RST_CPL) */
+	enable_bios_reset_cpl();
+
+	/*
+	 * Poll for bit 8 to check if PCODE has completed its action in response
+	 * to BIOS Reset complete.  We wait here till 1 ms for the bit to get
+	 * set.
+	 */
+	start = get_timer(0);
+	while (!(readl(MCHBAR_REG(BIOS_RESET_CPL)) & PCODE_INIT_DONE)) {
+		if (get_timer(start) > 1) {
+			debug("PCODE Init Done timeout\n");
+			return -ETIMEDOUT;
+		}
+		udelay(100);
+	}
+	debug("PUNIT init complete\n");
+
+	return 0;
+}
+
+static int apl_punit_probe(struct udevice *dev)
+{
+	if (spl_phase() == PHASE_SPL)
+		return punit_init(dev);
+
+	return 0;
+}
+
+static const struct udevice_id apl_syscon_ids[] = {
+	{ .compatible = "intel,apl-punit", .data = X86_SYSCON_PUNIT },
+	{ }
+};
+
+U_BOOT_DRIVER(syscon_intel_punit) = {
+	.name		= "intel_punit_syscon",
+	.id		= UCLASS_SYSCON,
+	.of_match	= apl_syscon_ids,
+	.probe		= apl_punit_probe,
+};