[v5,2/7] qcom: spm: Add Subsystem Power Manager driver (SAW2)

Message ID 1409870132-16929-3-git-send-email-lina.iyer@linaro.org
State New
Headers show

Commit Message

Lina Iyer Sept. 4, 2014, 10:35 p.m.
Based on work by many authors, available at codeaurora.org

SPM is a hardware block that controls the peripheral logic surrounding
the application cores (cpu/l$). When the core executes WFI instruction,
the SPM takes over the putting the core in low power state as
configured. The wake up for the SPM is an interrupt at the GIC, which
then completes the rest of low power mode sequence and brings the core
out of low power mode.

The SPM has a set of control registers that configure the SPMs
individually based on the type of the core and the runtime conditions.
SPM is a finite state machine block to which a sequence is provided and
it interprets the bytes  and executes them in sequence. Each low power
mode that the core can enter into is provided to the SPM as a sequence.

Configure the SPM to set the core (cpu or L2) into its low power mode,
the index of the first command in the sequence is set in the SPM_CTL
register. When the core executes ARM wfi instruction, it triggers the
SPM state machine to start executing from that index. The SPM state
machine waits until the interrupt occurs and starts executing the rest
of the sequence until it hits the end of the sequence. The end of the
sequence jumps the core out of its low power mode.

Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
[lina: simplify the driver for initial submission, clean up and update
commit text]
---
 drivers/soc/qcom/Makefile  |   1 +
 drivers/soc/qcom/spm-drv.h |  69 ++++++++++++++++
 drivers/soc/qcom/spm.c     | 192 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 262 insertions(+)
 create mode 100644 drivers/soc/qcom/spm-drv.h
 create mode 100644 drivers/soc/qcom/spm.c

Comments

Pramod Gurav Sept. 8, 2014, 9:48 a.m. | #1
Hi Lina,

On Friday 05 September 2014 04:05 AM, Lina Iyer wrote:

>  drivers/soc/qcom/spm.c     | 192 +++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 262 insertions(+)
>  create mode 100644 drivers/soc/qcom/spm-drv.h
>  create mode 100644 drivers/soc/qcom/spm.c
> 
> diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
> index 70d52ed..20b329f 100644
> --- a/drivers/soc/qcom/Makefile
> +++ b/drivers/soc/qcom/Makefile
> @@ -1,3 +1,4 @@
>  obj-$(CONFIG_QCOM_GSBI)	+=	qcom_gsbi.o
> +obj-$(CONFIG_QCOM_PM)	+=	spm.o

CONFIG_QCOM_PM is missing in Kconfig hence this driver wont build. I see
it is added in patch #3. Please move it to this patch so that this
driver builds.

>  CFLAGS_scm.o :=$(call as-instr,.arch_extension sec,-DREQUIRES_SEC=1)
>  obj-$(CONFIG_QCOM_SCM) += scm.o scm-boot.o
> diff --git a/drivers/soc/qcom/spm-drv.h b/drivers/soc/qcom/spm-drv.h
> new file mode 100644
> index 0000000..e91df44

Thanks
Pramod

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Patch

diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
index 70d52ed..20b329f 100644
--- a/drivers/soc/qcom/Makefile
+++ b/drivers/soc/qcom/Makefile
@@ -1,3 +1,4 @@ 
 obj-$(CONFIG_QCOM_GSBI)	+=	qcom_gsbi.o
+obj-$(CONFIG_QCOM_PM)	+=	spm.o
 CFLAGS_scm.o :=$(call as-instr,.arch_extension sec,-DREQUIRES_SEC=1)
 obj-$(CONFIG_QCOM_SCM) += scm.o scm-boot.o
diff --git a/drivers/soc/qcom/spm-drv.h b/drivers/soc/qcom/spm-drv.h
new file mode 100644
index 0000000..e91df44
--- /dev/null
+++ b/drivers/soc/qcom/spm-drv.h
@@ -0,0 +1,69 @@ 
+/* Copyright (c) 2011-2014, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+#ifndef __QCOM_SPM_DRIVER_H
+#define __QCOM_SPM_DRIVER_H
+
+enum {
+	MSM_SPM_REG_SAW2_CFG,
+	MSM_SPM_REG_SAW2_AVS_CTL,
+	MSM_SPM_REG_SAW2_AVS_HYSTERESIS,
+	MSM_SPM_REG_SAW2_SPM_CTL,
+	MSM_SPM_REG_SAW2_PMIC_DLY,
+	MSM_SPM_REG_SAW2_AVS_LIMIT,
+	MSM_SPM_REG_SAW2_AVS_DLY,
+	MSM_SPM_REG_SAW2_SPM_DLY,
+	MSM_SPM_REG_SAW2_PMIC_DATA_0,
+	MSM_SPM_REG_SAW2_PMIC_DATA_1,
+	MSM_SPM_REG_SAW2_PMIC_DATA_2,
+	MSM_SPM_REG_SAW2_PMIC_DATA_3,
+	MSM_SPM_REG_SAW2_PMIC_DATA_4,
+	MSM_SPM_REG_SAW2_PMIC_DATA_5,
+	MSM_SPM_REG_SAW2_PMIC_DATA_6,
+	MSM_SPM_REG_SAW2_PMIC_DATA_7,
+	MSM_SPM_REG_SAW2_RST,
+
+	MSM_SPM_REG_NR_INITIALIZE = MSM_SPM_REG_SAW2_RST,
+
+	MSM_SPM_REG_SAW2_ID,
+	MSM_SPM_REG_SAW2_SECURE,
+	MSM_SPM_REG_SAW2_STS0,
+	MSM_SPM_REG_SAW2_STS1,
+	MSM_SPM_REG_SAW2_STS2,
+	MSM_SPM_REG_SAW2_VCTL,
+	MSM_SPM_REG_SAW2_SEQ_ENTRY,
+	MSM_SPM_REG_SAW2_SPM_STS,
+	MSM_SPM_REG_SAW2_AVS_STS,
+	MSM_SPM_REG_SAW2_PMIC_STS,
+	MSM_SPM_REG_SAW2_VERSION,
+
+	MSM_SPM_REG_NR,
+};
+
+struct msm_spm_mode {
+	u32 mode;
+	u8 *cmd;
+	u32 start_addr;
+};
+
+struct msm_spm_driver_data {
+	void __iomem *reg_base_addr;
+	u32 reg_shadow[MSM_SPM_REG_NR];
+	u32 *reg_offsets;
+	struct msm_spm_mode *modes;
+	u32 num_modes;
+};
+
+int msm_spm_drv_init(struct msm_spm_driver_data *dev);
+int msm_spm_drv_set_low_power_mode(struct msm_spm_driver_data *dev, u32 addr);
+int msm_spm_drv_set_spm_enable(struct msm_spm_driver_data *dev, bool enable);
+
+#endif /* __QCOM_SPM_DRIVER_H */
diff --git a/drivers/soc/qcom/spm.c b/drivers/soc/qcom/spm.c
new file mode 100644
index 0000000..81e578c
--- /dev/null
+++ b/drivers/soc/qcom/spm.c
@@ -0,0 +1,192 @@ 
+/* Copyright (c) 2011-2014, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+
+#include "spm-drv.h"
+
+#define NUM_SEQ_ENTRY 32
+#define SPM_CTL_ENABLE BIT(0)
+
+static u32 msm_spm_reg_offsets_saw2_v2_1[MSM_SPM_REG_NR] = {
+	[MSM_SPM_REG_SAW2_SECURE]		= 0x00,
+	[MSM_SPM_REG_SAW2_ID]			= 0x04,
+	[MSM_SPM_REG_SAW2_CFG]			= 0x08,
+	[MSM_SPM_REG_SAW2_SPM_STS]		= 0x0C,
+	[MSM_SPM_REG_SAW2_AVS_STS]		= 0x10,
+	[MSM_SPM_REG_SAW2_PMIC_STS]		= 0x14,
+	[MSM_SPM_REG_SAW2_RST]			= 0x18,
+	[MSM_SPM_REG_SAW2_VCTL]			= 0x1C,
+	[MSM_SPM_REG_SAW2_AVS_CTL]		= 0x20,
+	[MSM_SPM_REG_SAW2_AVS_LIMIT]		= 0x24,
+	[MSM_SPM_REG_SAW2_AVS_DLY]		= 0x28,
+	[MSM_SPM_REG_SAW2_AVS_HYSTERESIS]	= 0x2C,
+	[MSM_SPM_REG_SAW2_SPM_CTL]		= 0x30,
+	[MSM_SPM_REG_SAW2_SPM_DLY]		= 0x34,
+	[MSM_SPM_REG_SAW2_PMIC_DATA_0]		= 0x40,
+	[MSM_SPM_REG_SAW2_PMIC_DATA_1]		= 0x44,
+	[MSM_SPM_REG_SAW2_PMIC_DATA_2]		= 0x48,
+	[MSM_SPM_REG_SAW2_PMIC_DATA_3]		= 0x4C,
+	[MSM_SPM_REG_SAW2_PMIC_DATA_4]		= 0x50,
+	[MSM_SPM_REG_SAW2_PMIC_DATA_5]		= 0x54,
+	[MSM_SPM_REG_SAW2_PMIC_DATA_6]		= 0x58,
+	[MSM_SPM_REG_SAW2_PMIC_DATA_7]		= 0x5C,
+	[MSM_SPM_REG_SAW2_SEQ_ENTRY]		= 0x80,
+	[MSM_SPM_REG_SAW2_VERSION]		= 0xFD0,
+};
+
+static void flush_shadow(struct msm_spm_driver_data *drv, u32 reg_index)
+{
+	writel_relaxed(drv->reg_shadow[reg_index],
+			drv->reg_base_addr + drv->reg_offsets[reg_index]);
+}
+
+static void load_shadow(struct msm_spm_driver_data *drv, u32 reg_index)
+{
+	drv->reg_shadow[reg_index] = readl_relaxed(drv->reg_base_addr +
+						drv->reg_offsets[reg_index]);
+}
+
+static inline void set_start_addr(struct msm_spm_driver_data *drv, u32 addr)
+{
+	/* Update bits 10:4 in the SPM CTL register */
+	addr &= 0x7F;
+	addr <<= 4;
+	drv->reg_shadow[MSM_SPM_REG_SAW2_SPM_CTL] &= 0xFFFFF80F;
+	drv->reg_shadow[MSM_SPM_REG_SAW2_SPM_CTL] |= addr;
+}
+
+int msm_spm_drv_set_low_power_mode(struct msm_spm_driver_data *drv, u32 mode)
+{
+	int i;
+	u32 start_addr = 0;
+
+	for (i = 0; i < drv->num_modes; i++) {
+		if (drv->modes[i].mode == mode) {
+			start_addr = drv->modes[i].start_addr;
+			break;
+		}
+	}
+
+	if (i == drv->num_modes)
+		return -EINVAL;
+
+	set_start_addr(drv, start_addr);
+	flush_shadow(drv, MSM_SPM_REG_SAW2_SPM_CTL);
+	/* Barrier to ensure we have written the start address */
+	wmb();
+
+	/* Update our shadow with the status changes, if any */
+	load_shadow(drv, MSM_SPM_REG_SAW2_SPM_STS);
+
+	return 0;
+}
+
+int msm_spm_drv_set_spm_enable(struct msm_spm_driver_data *drv, bool enable)
+{
+	u32 value = enable ? 0x01 : 0x00;
+
+	/* Update SPM_CTL to enable/disable the SPM */
+	if ((drv->reg_shadow[MSM_SPM_REG_SAW2_SPM_CTL] & SPM_CTL_ENABLE)
+								!= value) {
+		/* Clear the existing value and update */
+		drv->reg_shadow[MSM_SPM_REG_SAW2_SPM_CTL] &= ~0x1;
+		drv->reg_shadow[MSM_SPM_REG_SAW2_SPM_CTL] |= value;
+		flush_shadow(drv, MSM_SPM_REG_SAW2_SPM_CTL);
+		/* Ensure we have enabled/disabled before returning */
+		wmb();
+	}
+
+	return 0;
+}
+
+static void flush_seq_data(struct msm_spm_driver_data *drv, u32 *reg_seq_entry)
+{
+	int i;
+
+	/* Write the 32 byte array into the SPM registers */
+	for (i = 0; i < NUM_SEQ_ENTRY; i++) {
+		writel_relaxed(reg_seq_entry[i],
+			drv->reg_base_addr
+			+ drv->reg_offsets[MSM_SPM_REG_SAW2_SEQ_ENTRY]
+			+ 4 * i);
+	}
+	/* Ensure that the changes are written */
+	wmb();
+}
+
+static void write_seq_data(struct msm_spm_driver_data *drv,
+		u32 *reg_seq_entry, u8 *cmd, u32 *offset)
+{
+	u32 cmd_w;
+	u32 offset_w = *offset / 4;
+	u8 last_cmd;
+
+	while (1) {
+		int i;
+
+		cmd_w = 0;
+		last_cmd = 0;
+		cmd_w = reg_seq_entry[offset_w];
+
+		for (i = (*offset % 4); i < 4; i++) {
+			last_cmd = *(cmd++);
+			cmd_w |=  last_cmd << (i * 8);
+			(*offset)++;
+			if (last_cmd == 0x0f)
+				break;
+		}
+
+		reg_seq_entry[offset_w++] = cmd_w;
+		if (last_cmd == 0x0f)
+			break;
+	}
+
+}
+
+int msm_spm_drv_init(struct msm_spm_driver_data *drv)
+{
+	int i;
+	int offset = 0;
+	u32 sequences[NUM_SEQ_ENTRY/4] = {0};
+
+	drv->reg_offsets = msm_spm_reg_offsets_saw2_v2_1;
+
+	/**
+	 * Compose the uint32 array based on the individual bytes of the SPM
+	 * sequence for each low power mode that we read from the DT.
+	 * The sequences are appended if there is space available in the
+	 * u32 after the end of the previous sequence.
+	 */
+	for (i = 0; i < drv->num_modes; i++) {
+		drv->modes[i].start_addr = offset;
+		write_seq_data(drv, &sequences[0], drv->modes[i].cmd, &offset);
+	}
+
+	/* Flush the integer array */
+	flush_seq_data(drv, &sequences[0]);
+
+	/**
+	 * Initialize the hardware with the control registers that
+	 * we have read.
+	 */
+	for (i = 0; i < MSM_SPM_REG_SAW2_PMIC_DATA_0; i++)
+		flush_shadow(drv, i);
+
+	return 0;
+}