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raw | patch | inline | side by side (from parent 1: 1fc39d6)
raw | patch | inline | side by side (from parent 1: 1fc39d6)
author | Dave Gerlach <d-gerlach@ti.com> | |
Fri, 2 Nov 2018 10:29:06 +0000 (15:59 +0530) | ||
committer | Tero Kristo <t-kristo@ti.com> | |
Tue, 6 Nov 2018 13:06:17 +0000 (15:06 +0200) |
Some boards (currently AM335x EVM-SK) provides s/w control via
GPIO to toggle VTT regulator to reduce power consumption in low
power state.
The VTT regulator should be disabled after enabling self-refresh on
suspend, and should be enabled before disabling self-refresh on resume.
This is to allow proper self-refresh entry/exit commands to be
transmitted to the memory.
Add support for toggling VTT regulator using DT properties.
Actual toggling happens in CM3 Firmware. The enable option & the GPIO
pin used is collected in A8 Core and then sent to CM3 using IPC
registers.
Note:
Here it is assumed that VTT Toggle will be done using a pin on GPIO-0
Instance. The reason is GPIO-0 is in wakeup domain.
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Keerthy <j-keerthy@ti.com>
GPIO to toggle VTT regulator to reduce power consumption in low
power state.
The VTT regulator should be disabled after enabling self-refresh on
suspend, and should be enabled before disabling self-refresh on resume.
This is to allow proper self-refresh entry/exit commands to be
transmitted to the memory.
Add support for toggling VTT regulator using DT properties.
Actual toggling happens in CM3 Firmware. The enable option & the GPIO
pin used is collected in A8 Core and then sent to CM3 using IPC
registers.
Note:
Here it is assumed that VTT Toggle will be done using a pin on GPIO-0
Instance. The reason is GPIO-0 is in wakeup domain.
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Keerthy <j-keerthy@ti.com>
Documentation/devicetree/bindings/soc/ti/wkup_m3_ipc.txt | patch | blob | history | |
drivers/soc/ti/wkup_m3_ipc.c | patch | blob | history | |
include/linux/wkup_m3_ipc.h | patch | blob | history |
diff --git a/Documentation/devicetree/bindings/soc/ti/wkup_m3_ipc.txt b/Documentation/devicetree/bindings/soc/ti/wkup_m3_ipc.txt
index 401550487ed6f69f036a810dd6e01edcef745b87..4cdbb60fd0d0bace26aed3155b7dcf942545275b 100644 (file)
...
};
};
...
};
};
+
+Support for VTT Toggle
+==================================
+In order to enable the support for VTT toggle during Suspend/Resume
+sequence needed by some boards (like AM335x EVM-SK & AM437x GP EVM),
+the below DT properties are required. It is possible to toggle VTT
+using one of two methods depending on the SoC being used, either
+GPIO0 toggle (AM335x and AM437x), or any GPIO with DS_PAD_CONFIG
+bits in the control module (AM437x only).
+
+VTT Toggle using GPIO0
+----------------------------------
+Supported by: AM335x and AM437x
+Used on: AM335x EVM-SK
+
+Optional properties:
+- ti,needs-vtt-toggle: Indicates that the boards requires VTT toggling
+ during suspend/resume.
+- ti,vtt-gpio-pin: Specifies the GPIO0 pin used for VTT toggle.
+
+Important Note:
+- Here it is assumed that VTT Toggle will be done using a pin on GPIO-0 Instance.
+ It will not work on any other GPIO using the above properties, regardless of
+ which part is being used.
+
+Example:
+ wkup_m3_ipc: wkup_m3_ipc@1324 {
+ compatible = "ti,am3352-wkup-m3-ipc";
+ ...
+ ...
+ ti,needs-vtt-toggle;
+ ti,vtt-gpio-pin = <7>;
+ ...
+ };
index f5cb8c0af09f3ab8ade4443ada270bf1f1eefa92..5a9c1f5042207f84390f4cdeebae538896b1a99c 100644 (file)
#define M3_FW_VERSION_MASK 0xffff
#define M3_WAKE_SRC_MASK 0xff
#define M3_FW_VERSION_MASK 0xffff
#define M3_WAKE_SRC_MASK 0xff
+#define IPC_MEM_TYPE_SHIFT (0x0)
+#define IPC_MEM_TYPE_MASK (0x7 << 0)
+#define IPC_VTT_STAT_SHIFT (0x3)
+#define IPC_VTT_STAT_MASK (0x1 << 3)
+#define IPC_VTT_GPIO_PIN_SHIFT (0x4)
+#define IPC_VTT_GPIO_PIN_MASK (0x3f << 4)
+
#define M3_STATE_UNKNOWN 0
#define M3_STATE_RESET 1
#define M3_STATE_INITED 2
#define M3_STATE_UNKNOWN 0
#define M3_STATE_RESET 1
#define M3_STATE_INITED 2
(m3_ipc->state != M3_STATE_UNKNOWN));
}
(m3_ipc->state != M3_STATE_UNKNOWN));
}
+static void wkup_m3_set_vtt_gpio(struct wkup_m3_ipc *m3_ipc, int gpio)
+{
+ m3_ipc->vtt_conf = (1 << IPC_VTT_STAT_SHIFT) |
+ (gpio << IPC_VTT_GPIO_PIN_SHIFT);
+}
+
/* Public functions */
/**
* wkup_m3_set_mem_type - Pass wkup_m3 which type of memory is in use
/* Public functions */
/**
* wkup_m3_set_mem_type - Pass wkup_m3 which type of memory is in use
/* Program each required IPC register then write defaults to others */
wkup_m3_ctrl_ipc_write(m3_ipc, m3_ipc->resume_addr, 0);
wkup_m3_ctrl_ipc_write(m3_ipc, m3_power_state, 1);
/* Program each required IPC register then write defaults to others */
wkup_m3_ctrl_ipc_write(m3_ipc, m3_ipc->resume_addr, 0);
wkup_m3_ctrl_ipc_write(m3_ipc, m3_power_state, 1);
- wkup_m3_ctrl_ipc_write(m3_ipc, m3_ipc->mem_type, 4);
+ wkup_m3_ctrl_ipc_write(m3_ipc, m3_ipc->mem_type |
+ m3_ipc->vtt_conf, 4);
wkup_m3_ctrl_ipc_write(m3_ipc, DS_IPC_DEFAULT, 2);
wkup_m3_ctrl_ipc_write(m3_ipc, DS_IPC_DEFAULT, 3);
wkup_m3_ctrl_ipc_write(m3_ipc, DS_IPC_DEFAULT, 2);
wkup_m3_ctrl_ipc_write(m3_ipc, DS_IPC_DEFAULT, 3);
static int wkup_m3_ipc_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
static int wkup_m3_ipc_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
- int irq, ret;
+ int irq, ret, temp;
phandle rproc_phandle;
struct rproc *m3_rproc;
struct resource *res;
struct task_struct *task;
struct wkup_m3_ipc *m3_ipc;
phandle rproc_phandle;
struct rproc *m3_rproc;
struct resource *res;
struct task_struct *task;
struct wkup_m3_ipc *m3_ipc;
+ struct device_node *np = dev->of_node;
m3_ipc = devm_kzalloc(dev, sizeof(*m3_ipc), GFP_KERNEL);
if (!m3_ipc)
m3_ipc = devm_kzalloc(dev, sizeof(*m3_ipc), GFP_KERNEL);
if (!m3_ipc)
m3_ipc->ops = &ipc_ops;
m3_ipc->ops = &ipc_ops;
+ if (of_find_property(np, "ti,needs-vtt-toggle", NULL) &&
+ !(of_property_read_u32(np, "ti,vtt-gpio-pin", &temp))) {
+ if (temp >= 0 && temp <= 31)
+ wkup_m3_set_vtt_gpio(m3_ipc, temp);
+ else
+ dev_warn(dev, "Invalid VTT GPIO(%d) pin\n", temp);
+ }
+
/*
* Wait for firmware loading completion in a thread so we
* can boot the wkup_m3 as soon as it's ready without holding
/*
* Wait for firmware loading completion in a thread so we
* can boot the wkup_m3 as soon as it's ready without holding
index e497e621dbb7f6e793f3e2e1230ab1da16daeb66..682efbb7d401e50e232d1d5098c8afe619ce9c5b 100644 (file)
int mem_type;
unsigned long resume_addr;
int mem_type;
unsigned long resume_addr;
+ int vtt_conf;
int state;
struct completion sync_complete;
int state;
struct completion sync_complete;