zephyr/drivers/serial/uart_pl011_ambiq.h

208 lines
7.3 KiB
C

/*
* Copyright (c) 2023 Antmicro <www.antmicro.com>
*
* SPDX-License-Identifier: Apache-2.0
*/
#ifndef ZEPHYR_DRIVERS_SERIAL_UART_PL011_AMBIQ_H_
#define ZEPHYR_DRIVERS_SERIAL_UART_PL011_AMBIQ_H_
#include <zephyr/device.h>
#include <zephyr/kernel.h>
#include <zephyr/pm/device.h>
#include <zephyr/pm/policy.h>
#include "uart_pl011_registers.h"
#include <am_mcu_apollo.h>
#define PWRCTRL_MAX_WAIT_US 5
static inline void pl011_ambiq_enable_clk(const struct device *dev)
{
get_uart(dev)->cr |= PL011_CR_AMBIQ_CLKEN;
}
static inline int pl011_ambiq_clk_set(const struct device *dev, uint32_t clk)
{
uint8_t clksel;
switch (clk) {
case 3000000:
clksel = PL011_CR_AMBIQ_CLKSEL_3MHZ;
break;
case 6000000:
clksel = PL011_CR_AMBIQ_CLKSEL_6MHZ;
break;
case 12000000:
clksel = PL011_CR_AMBIQ_CLKSEL_12MHZ;
break;
case 24000000:
clksel = PL011_CR_AMBIQ_CLKSEL_24MHZ;
break;
default:
return -EINVAL;
}
get_uart(dev)->cr |= FIELD_PREP(PL011_CR_AMBIQ_CLKSEL, clksel);
return 0;
}
static inline int clk_enable_ambiq_uart(const struct device *dev, uint32_t clk)
{
pl011_ambiq_enable_clk(dev);
return pl011_ambiq_clk_set(dev, clk);
}
#ifdef CONFIG_PM_DEVICE
/* Register status record.
* The register status will be preserved to this variable before entering sleep mode,
* and they will be restored after wake up.
*/
typedef struct {
bool bValid;
uint32_t regILPR;
uint32_t regIBRD;
uint32_t regFBRD;
uint32_t regLCRH;
uint32_t regCR;
uint32_t regIFLS;
uint32_t regIER;
} uart_register_state_t;
static uart_register_state_t sRegState[AM_REG_UART_NUM_MODULES];
static int uart_ambiq_pm_action(const struct device *dev, enum pm_device_action action)
{
int key;
/*Uart module number*/
uint32_t ui32Module = ((uint32_t)get_uart(dev) == UART0_BASE) ? 0 : 1;
/*Uart Power module*/
am_hal_pwrctrl_periph_e eUARTPowerModule =
((am_hal_pwrctrl_periph_e)(AM_HAL_PWRCTRL_PERIPH_UART0 + ui32Module));
/*Uart register status*/
uart_register_state_t *pRegisterStatus = &sRegState[ui32Module];
/* Decode the requested power state and update UART operation accordingly.*/
switch (action) {
/* Turn on the UART. */
case PM_DEVICE_ACTION_RESUME:
/* Make sure we don't try to restore an invalid state.*/
if (!pRegisterStatus->bValid) {
return -EPERM;
}
/*The resume and suspend actions may be executed back-to-back,
* so we add a busy wait here for stabilization.
*/
k_busy_wait(100);
/* Enable power control.*/
am_hal_pwrctrl_periph_enable(eUARTPowerModule);
/* Restore UART registers*/
key = irq_lock();
UARTn(ui32Module)->ILPR = pRegisterStatus->regILPR;
UARTn(ui32Module)->IBRD = pRegisterStatus->regIBRD;
UARTn(ui32Module)->FBRD = pRegisterStatus->regFBRD;
UARTn(ui32Module)->LCRH = pRegisterStatus->regLCRH;
UARTn(ui32Module)->CR = pRegisterStatus->regCR;
UARTn(ui32Module)->IFLS = pRegisterStatus->regIFLS;
UARTn(ui32Module)->IER = pRegisterStatus->regIER;
pRegisterStatus->bValid = false;
irq_unlock(key);
return 0;
case PM_DEVICE_ACTION_SUSPEND:
while ((get_uart(dev)->fr & PL011_FR_BUSY) != 0)
;
/* Preserve UART registers*/
key = irq_lock();
pRegisterStatus->regILPR = UARTn(ui32Module)->ILPR;
pRegisterStatus->regIBRD = UARTn(ui32Module)->IBRD;
pRegisterStatus->regFBRD = UARTn(ui32Module)->FBRD;
pRegisterStatus->regLCRH = UARTn(ui32Module)->LCRH;
pRegisterStatus->regCR = UARTn(ui32Module)->CR;
pRegisterStatus->regIFLS = UARTn(ui32Module)->IFLS;
pRegisterStatus->regIER = UARTn(ui32Module)->IER;
pRegisterStatus->bValid = true;
irq_unlock(key);
/* Clear all interrupts before sleeping as having a pending UART
* interrupt burns power.
*/
UARTn(ui32Module)->IEC = 0xFFFFFFFF;
/* If the user is going to sleep, certain bits of the CR register
* need to be 0 to be low power and have the UART shut off.
* Since the user either wishes to retain state which takes place
* above or the user does not wish to retain state, it is acceptable
* to set the entire CR register to 0.
*/
UARTn(ui32Module)->CR = 0;
/* Disable power control.*/
am_hal_pwrctrl_periph_disable(eUARTPowerModule);
return 0;
default:
return -ENOTSUP;
}
}
#endif /* CONFIG_PM_DEVICE */
/* Problem: writes to power configure register takes some time to take effective.
* Solution: Check device's power status to ensure that register has taken effective.
* Note: busy wait is not allowed to use here due to UART is initiated before timer starts.
*/
#if defined(CONFIG_SOC_SERIES_APOLLO3X)
#define DEVPWRSTATUS_OFFSET 0x10
#define HCPA_MASK 0x4
#define AMBIQ_UART_DEFINE(n) \
PM_DEVICE_DT_INST_DEFINE(n, uart_ambiq_pm_action); \
static int pwr_on_ambiq_uart_##n(void) \
{ \
uint32_t addr = DT_REG_ADDR(DT_INST_PHANDLE(n, ambiq_pwrcfg)) + \
DT_INST_PHA(n, ambiq_pwrcfg, offset); \
uint32_t pwr_status_addr = addr + DEVPWRSTATUS_OFFSET; \
sys_write32((sys_read32(addr) | DT_INST_PHA(n, ambiq_pwrcfg, mask)), addr); \
while (!(sys_read32(pwr_status_addr) & HCPA_MASK)) { \
}; \
return 0; \
} \
static inline int clk_enable_ambiq_uart_##n(const struct device *dev, uint32_t clk) \
{ \
return clk_enable_ambiq_uart(dev, clk); \
}
#else
#define DEVPWRSTATUS_OFFSET 0x4
#define AMBIQ_UART_DEFINE(n) \
PM_DEVICE_DT_INST_DEFINE(n, uart_ambiq_pm_action); \
static int pwr_on_ambiq_uart_##n(void) \
{ \
uint32_t addr = DT_REG_ADDR(DT_INST_PHANDLE(n, ambiq_pwrcfg)) + \
DT_INST_PHA(n, ambiq_pwrcfg, offset); \
uint32_t pwr_status_addr = addr + DEVPWRSTATUS_OFFSET; \
sys_write32((sys_read32(addr) | DT_INST_PHA(n, ambiq_pwrcfg, mask)), addr); \
while ((sys_read32(pwr_status_addr) & DT_INST_PHA(n, ambiq_pwrcfg, mask)) != \
DT_INST_PHA(n, ambiq_pwrcfg, mask)) { \
}; \
return 0; \
} \
static inline int clk_enable_ambiq_uart_##n(const struct device *dev, uint32_t clk) \
{ \
return clk_enable_ambiq_uart(dev, clk); \
}
#endif
#endif /* ZEPHYR_DRIVERS_SERIAL_UART_PL011_AMBIQ_H_ */