diff options
| author | Dave Gerlach <d-gerlach@ti.com> | 2022-04-09 14:12:15 -0700 |
|---|---|---|
| committer | Nishanth Menon <nm@ti.com> | 2022-04-22 18:12:35 -0500 |
| commit | f226041424cf87245d39a1b2dfae304308b36b6b (patch) | |
| tree | febf01dd536de03e3b004e5d1100d01b367e1a4d /drivers/soc/ti | |
| parent | 12eeb74925da70eb39d90abead9de9793be3d4c8 (diff) | |
soc: ti: wkup_m3_ipc: Add support for toggling VTT regulator
Some boards like the AM335x EVM-SK and AM437x GP EVM provide software
control via a GPIO pin to toggle the DDR VTT regulator to reduce power
consumption in low power states.
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.
The "ti,vtt-gpio-pin" device tree property in the wkup_m3_ipc node
specifies which GPIO pin to use. This property is communicated to the
Wakeup Cortex M3 co-processor where the actual toggling of the GPIO pin
happens in CM3 firmware [1].
Please note that the GPIO pin must be on the GPIO0 module as that module
is in the wakeup power domain.
[1] https://git.ti.com/cgit/processor-firmware/ti-amx3-cm3-pm-firmware/tree/src/pm_services/ddr.c?h=08.02.00.006#n190
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Keerthy <j-keerthy@ti.com>
[dfustini: remove the unnecessary "ti,needs-vtt-toggle" property]
Signed-off-by: Drew Fustini <dfustini@baylibre.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Link: https://lore.kernel.org/r/20220409211215.2529387-3-dfustini@baylibre.com
Diffstat (limited to 'drivers/soc/ti')
| -rw-r--r-- | drivers/soc/ti/wkup_m3_ipc.c | 26 |
1 files changed, 24 insertions, 2 deletions
diff --git a/drivers/soc/ti/wkup_m3_ipc.c b/drivers/soc/ti/wkup_m3_ipc.c index f145e65041fd..48659758228e 100644 --- a/drivers/soc/ti/wkup_m3_ipc.c +++ b/drivers/soc/ti/wkup_m3_ipc.c @@ -40,6 +40,13 @@ #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 @@ -215,6 +222,12 @@ static int wkup_m3_is_available(struct wkup_m3_ipc *m3_ipc) (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 @@ -294,7 +307,8 @@ static int wkup_m3_prepare_low_power(struct wkup_m3_ipc *m3_ipc, int state) /* 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); @@ -433,12 +447,13 @@ static int wkup_m3_rproc_boot_thread(void *arg) 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; + struct device_node *np = dev->of_node; m3_ipc = devm_kzalloc(dev, sizeof(*m3_ipc), GFP_KERNEL); if (!m3_ipc) @@ -494,6 +509,13 @@ static int wkup_m3_ipc_probe(struct platform_device *pdev) m3_ipc->ops = &ipc_ops; + if (!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 |