coreboot-libre-fam15h-rdimm/3rdparty/chromeec/chip/mchp/gpio.c

434 lines
11 KiB
C

/* Copyright 2017 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
/* GPIO module for MCHP MEC */
#include "common.h"
#include "gpio.h"
#include "hooks.h"
#include "registers.h"
#include "system.h"
#include "task.h"
#include "timer.h"
#include "util.h"
#include "lpc_chip.h"
#include "tfdp_chip.h"
/* Console output macros */
#define CPUTS(outstr) cputs(CC_LPC, outstr)
#define CPRINTS(format, args...) cprints(CC_LPC, format, ## args)
struct gpio_int_mapping {
int8_t girq_id;
int8_t port_offset;
};
/*
* Mapping from GPIO port to GIRQ info
* MEC17xx each bank contains 32 GPIO's.
* Pin Id is the bit position [0:31]
* Bank GPIO's GIRQ
* 0 0000 - 0036 11
* 1 0040 - 0076 10
* 2 0100 - 0135 9
* 3 0140 - 0175 8
* 4 0200 - 0235 12
* 5 0240 - 0276 26
*/
static const struct gpio_int_mapping int_map[6] = {
{ 11, 0 }, { 10, 1 }, { 9, 2 },
{ 8, 3 }, { 12, 4 }, { 26, 5 }
};
/*
* NOTE: GCC __builtin_ffs(val) returns (index + 1) of least significant
* 1-bit of val or if val == 0 returns 0
*/
void gpio_set_alternate_function(uint32_t port, uint32_t mask, int func)
{
int i;
uint32_t val;
while (mask) {
i = __builtin_ffs(mask) - 1;
val = MCHP_GPIO_CTL(port, i);
val &= ~(BIT(12) | BIT(13));
/* mux_control = 0 indicates GPIO */
if (func > 0)
val |= (func & 0x3) << 12;
MCHP_GPIO_CTL(port, i) = val;
mask &= ~BIT(i);
}
}
test_mockable int gpio_get_level(enum gpio_signal signal)
{
uint32_t mask = gpio_list[signal].mask;
int i;
uint32_t val;
if (mask == 0)
return 0;
i = GPIO_MASK_TO_NUM(mask);
val = MCHP_GPIO_CTL(gpio_list[signal].port, i);
return (val & BIT(24)) ? 1 : 0;
}
void gpio_set_level(enum gpio_signal signal, int value)
{
uint32_t mask = gpio_list[signal].mask;
int i;
if (mask == 0)
return;
i = GPIO_MASK_TO_NUM(mask);
if (value)
MCHP_GPIO_CTL(gpio_list[signal].port, i) |= BIT(16);
else
MCHP_GPIO_CTL(gpio_list[signal].port, i) &= ~BIT(16);
}
/*
* Add support for new #ifdef CONFIG_CMD_GPIO_POWER_DOWN.
* If GPIO_POWER_DONW flag is set force GPIO Control to
* GPIO input, interrupt detect disabled, power control field
* in bits[3:2]=10b.
* NOTE: if interrupt detect is enabled when pin is powered down
* then a false edge may be detected.
*
*/
void gpio_set_flags_by_mask(uint32_t port, uint32_t mask, uint32_t flags)
{
int i;
uint32_t val;
while (mask) {
i = GPIO_MASK_TO_NUM(mask);
mask &= ~BIT(i);
val = MCHP_GPIO_CTL(port, i);
#ifdef CONFIG_GPIO_POWER_DOWN
if (flags & GPIO_POWER_DOWN) {
val = (MCHP_GPIO_CTRL_PWR_OFF +
MCHP_GPIO_INTDET_DISABLED);
MCHP_GPIO_CTL(port, i) = val;
continue;
}
#endif
val &= ~(MCHP_GPIO_CTRL_PWR_MASK);
val |= MCHP_GPIO_CTRL_PWR_VTR;
/*
* Select open drain first, so that we don't
* glitch the signal when changing the line to
* an output.
*/
if (flags & GPIO_OPEN_DRAIN)
val |= (MCHP_GPIO_OPEN_DRAIN);
else
val &= ~(MCHP_GPIO_OPEN_DRAIN);
if (flags & GPIO_OUTPUT) {
val |= (MCHP_GPIO_OUTPUT);
val &= ~(MCHP_GPIO_OUTSEL_PAR);
} else {
val &= ~(MCHP_GPIO_OUTPUT);
val |= (MCHP_GPIO_OUTSEL_PAR);
}
/* Handle pull-up / pull-down */
val &= ~(MCHP_GPIO_CTRL_PUD_MASK);
if (flags & GPIO_PULL_UP)
val |= MCHP_GPIO_CTRL_PUD_PU;
else if (flags & GPIO_PULL_DOWN)
val |= MCHP_GPIO_CTRL_PUD_PD;
else
val |= MCHP_GPIO_CTRL_PUD_NONE;
/* Set up interrupt */
val &= ~(MCHP_GPIO_INTDET_MASK);
switch (flags & GPIO_INT_ANY) {
case GPIO_INT_F_RISING:
val |= MCHP_GPIO_INTDET_EDGE_RIS;
break;
case GPIO_INT_F_FALLING:
val |= MCHP_GPIO_INTDET_EDGE_FALL;
break;
case GPIO_INT_BOTH: /* both edges */
val |= MCHP_GPIO_INTDET_EDGE_BOTH;
break;
case GPIO_INT_F_LOW:
val |= MCHP_GPIO_INTDET_LVL_LO;
break;
case GPIO_INT_F_HIGH:
val |= MCHP_GPIO_INTDET_LVL_HI;
break;
default:
val |= MCHP_GPIO_INTDET_DISABLED;
break;
}
/* Set up level */
if (flags & GPIO_HIGH)
val |= (MCHP_GPIO_CTRL_OUT_LVL);
else if (flags & GPIO_LOW)
val &= ~(MCHP_GPIO_CTRL_OUT_LVL);
MCHP_GPIO_CTL(port, i) = val;
}
}
void gpio_power_off_by_mask(uint32_t port, uint32_t mask)
{
int i;
while (mask) {
i = GPIO_MASK_TO_NUM(mask);
mask &= ~BIT(i);
MCHP_GPIO_CTL(port, i) = (MCHP_GPIO_CTRL_PWR_OFF +
MCHP_GPIO_INTDET_DISABLED);
}
}
int gpio_power_off(enum gpio_signal signal)
{
int i, port;
if (gpio_list[signal].mask == 0)
return EC_ERROR_INVAL;
i = GPIO_MASK_TO_NUM(gpio_list[signal].mask);
port = gpio_list[signal].port;
MCHP_GPIO_CTL(port, i) = (MCHP_GPIO_CTRL_PWR_OFF +
MCHP_GPIO_INTDET_DISABLED);
return EC_SUCCESS;
}
/*
* gpio_list[signal].port = [0, 6] each port contains up to 32 pins
* gpio_list[signal].mask = bit mask in 32-bit port
* NOTE: MCHP GPIO are always aggregated not direct connected to NVIC.
* GPIO's are aggregated into banks of 32 pins.
* Each bank/port are connected to a GIRQ.
* int_map[port].girq_id is the GIRQ ID
* The bit number in the GIRQ registers is the same as the bit number
* in the GPIO bank.
*/
int gpio_enable_interrupt(enum gpio_signal signal)
{
int i, port, girq_id;
if (gpio_list[signal].mask == 0)
return EC_SUCCESS;
i = GPIO_MASK_TO_NUM(gpio_list[signal].mask);
port = gpio_list[signal].port;
girq_id = int_map[port].girq_id;
MCHP_INT_ENABLE(girq_id) = BIT(i);
MCHP_INT_BLK_EN |= BIT(girq_id);
return EC_SUCCESS;
}
int gpio_disable_interrupt(enum gpio_signal signal)
{
int i, port, girq_id;
if (gpio_list[signal].mask == 0)
return EC_SUCCESS;
i = GPIO_MASK_TO_NUM(gpio_list[signal].mask);
port = gpio_list[signal].port;
girq_id = int_map[port].girq_id;
MCHP_INT_DISABLE(girq_id) = BIT(i);
return EC_SUCCESS;
}
/*
* MCHP Interrupt Source is R/W1C no need for read-modify-write.
* GPIO's are aggregated meaning the NVIC Pending bit may be
* set for another GPIO in the GIRQ. You can clear NVIC pending
* and the hardware should re-assert it within one Cortex-M4 clock.
* If the Cortex-M4 is clocked slower than AHB then the Cortex-M4
* will take longer to register the interrupt. Not clearing NVIC
* pending leave a pending status if only the GPIO this routine
* clears is pending.
* NVIC (system control) register space is strongly-ordered
* Interrupt Aggregator is in Device space (system bus connected
* to AHB) with the Cortex-M4 write buffer.
* We need to insure the write to aggregator register in device
* AHB space completes before NVIC pending is cleared.
* The Cortex-M4 memory ordering rules imply Device access
* comes before strongly ordered access. Cortex-M4 will not re-order
* the writes. Due to the presence of the write buffer a DSB will
* not guarantee the clearing of the device status completes. Add
* a read back before clearing NVIC pending.
* GIRQ 8, 9, 10, 11, 12, 26 map to NVIC inputs 0, 1, 2, 3, 4, and 18.
*/
int gpio_clear_pending_interrupt(enum gpio_signal signal)
{
int i, port, girq_id;
if (gpio_list[signal].mask == 0)
return EC_SUCCESS;
i = GPIO_MASK_TO_NUM(gpio_list[signal].mask);
port = gpio_list[signal].port;
girq_id = int_map[port].girq_id;
/* Clear interrupt source sticky status bit even if not enabled */
MCHP_INT_SOURCE(girq_id) = BIT(i);
i = MCHP_INT_SOURCE(girq_id);
task_clear_pending_irq(girq_id - 8);
return EC_SUCCESS;
}
/*
* MCHP NOTE - called from main before scheduler started
*/
void gpio_pre_init(void)
{
int i;
int flags;
int is_warm = system_is_reboot_warm();
const struct gpio_info *g = gpio_list;
for (i = 0; i < GPIO_COUNT; i++, g++) {
flags = g->flags;
if (flags & GPIO_DEFAULT)
continue;
/*
* If this is a warm reboot, don't set the output levels or
* we'll shut off the AP.
*/
if (is_warm)
flags &= ~(GPIO_LOW | GPIO_HIGH);
gpio_set_flags_by_mask(g->port, g->mask, flags);
/* Use as GPIO, not alternate function */
gpio_set_alternate_function(g->port, g->mask, -1);
}
}
/* Clear any interrupt flags before enabling GPIO interrupt
* Original code has flaws.
* Writing result register to source only clears bits that have their
* enable and sources bits set.
* We must clear the NVIC pending R/W bit before setting NVIC enable.
* NVIC Pending is only cleared by the NVIC HW on ISR entry.
* Modifications are:
* 1. Clear all status bits in each GPIO GIRQ. This assumes any edges
* will occur after gpio_init. The old code is also making this
* assumption for the GPIO's that have been enabled.
* 2. Clear NVIC pending to prevent ISR firing on false edge.
*/
#define ENABLE_GPIO_GIRQ(x) \
do { \
MCHP_INT_SOURCE(x) = 0xfffffffful; \
task_clear_pending_irq(MCHP_IRQ_GIRQ ## x); \
task_enable_irq(MCHP_IRQ_GIRQ ## x); \
} while (0)
static void gpio_init(void)
{
ENABLE_GPIO_GIRQ(8);
ENABLE_GPIO_GIRQ(9);
ENABLE_GPIO_GIRQ(10);
ENABLE_GPIO_GIRQ(11);
ENABLE_GPIO_GIRQ(12);
ENABLE_GPIO_GIRQ(26);
}
DECLARE_HOOK(HOOK_INIT, gpio_init, HOOK_PRIO_DEFAULT);
/************************************************************************/
/* Interrupt handlers */
/**
* Handler for each GIRQ interrupt. This reads and clears the interrupt
* bits for the GIRQ interrupt, then finds and calls the corresponding
* GPIO interrupt handlers.
*
* @param girq GIRQ index
* @param port zero based GPIO port number [0, 5]
* @note __builtin_ffs(x) returns bitpos+1 of least significant 1-bit
* in x or 0 if no bits are set.
*/
static void gpio_interrupt(int girq, int port)
{
int i, bit;
const struct gpio_info *g = gpio_list;
uint32_t sts = MCHP_INT_RESULT(girq);
/* RW1C, no need for read-modify-write */
MCHP_INT_SOURCE(girq) = sts;
trace12(0, GPIO, 0, "GPIO GIRQ %d result = 0x%08x", girq, sts);
trace12(0, GPIO, 0, "GPIO ParIn[%d] = 0x%08x",
port, MCHP_GPIO_PARIN(port));
for (i = 0; (i < GPIO_IH_COUNT) && sts; ++i, ++g) {
if (g->port != port)
continue;
bit = __builtin_ffs(g->mask);
if (bit) {
bit--;
if (sts & BIT(bit)) {
trace12(0, GPIO, 0,
"Bit[%d]: handler @ 0x%08x", bit,
(uint32_t)gpio_irq_handlers[i]);
gpio_irq_handlers[i](i);
}
sts &= ~BIT(bit);
}
}
}
#define GPIO_IRQ_FUNC(irqfunc, girq, port)\
void irqfunc(void) \
{ \
gpio_interrupt(girq, port);\
}
GPIO_IRQ_FUNC(__girq_8_interrupt, 8, 3);
GPIO_IRQ_FUNC(__girq_9_interrupt, 9, 2);
GPIO_IRQ_FUNC(__girq_10_interrupt, 10, 1);
GPIO_IRQ_FUNC(__girq_11_interrupt, 11, 0);
GPIO_IRQ_FUNC(__girq_12_interrupt, 12, 4);
GPIO_IRQ_FUNC(__girq_26_interrupt, 26, 5);
#undef GPIO_IRQ_FUNC
/*
* Declare IRQs. Nesting this macro inside the GPIO_IRQ_FUNC macro works
* poorly because DECLARE_IRQ() stringizes its inputs.
*/
DECLARE_IRQ(MCHP_IRQ_GIRQ8, __girq_8_interrupt, 1);
DECLARE_IRQ(MCHP_IRQ_GIRQ9, __girq_9_interrupt, 1);
DECLARE_IRQ(MCHP_IRQ_GIRQ10, __girq_10_interrupt, 1);
DECLARE_IRQ(MCHP_IRQ_GIRQ11, __girq_11_interrupt, 1);
DECLARE_IRQ(MCHP_IRQ_GIRQ12, __girq_12_interrupt, 1);
DECLARE_IRQ(MCHP_IRQ_GIRQ26, __girq_26_interrupt, 1);