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/*
* Copyright 2023 NXP
*
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @file
* @brief Driver for NXP's IRQ_STEER IP.
*
* Below you may find some useful information that will help you better understand how the
* driver works. The ">" sign is used to mark ideas that are considered important and should
* be taken note of.
*
* 1) What is the IRQ_STEER IP?
* - in Zephyr terminology, the IRQ_STEER can be considered an interrupt aggregator. As such,
* its main goal is to multiplex multiple interrupt lines into a single/multiple ones.
*
* 2) How does the IRQ_STEER IP work?
* - below you may find a diagram meant to give you an intuition regarding the IP's structure
* and how it works (all of the information below is applicable to i.MX8MP but it can be
* extended to any NXP SoC using the IRQ_STEER IP):
*
* SYSTEM_INTID[0:159]
* |
* MASK[0:4]------ |
* | |
* +------+
* | |
* |32 AND|
* | |
* +------+
* |
* SET[0:4]------ |
* | |
* +------+
* | |
* |32 OR |
* | |
* +------+
* |__________ STATUS[0:4]
* |
* +------+
* |GROUP |
* | BY |
* | 64 |
* +------+
* | | |
* _____________| | |________________
* | | |
* MASTER_IN[0] MASTER_IN[1] MASTER_IN[2]
* | | |
* | | |
* |_____________ | _______________|
* | | |
* +------+
* | |
* | AND | ---------- MINTDIS[0:2]
* | |
* +------+
* | | |
* _____________| | |________________
* | | |
* MASTER_OUT[0] MASTER_OUT[1] MASTER_OUT[2]
*
* - initially, all SYSTEM_INTID are grouped by 32 => 5 groups.
*
* > each of these groups is controlled by a MASK, SET and STATUS index as follows:
*
* MASK/SET/STATUS[0] => SYSTEM_INTID[159:128]
* MASK/SET/STATUS[1] => SYSTEM_INTID[127:96]
* MASK/SET/STATUS[2] => SYSTEM_INTID[95:64]
* MASK/SET/STATUS[3] => SYSTEM_INTID[63:32]
* MASK/SET/STATUS[4] => SYSTEM_INTID[31:0]
*
* > after that, all SYSTEM_INTID are grouped by 64 as follows:
*
* SYSTEM_INTID[159:96] => MASTER_IN[2]
* SYSTEM_INTID[95:32] => MASTER_IN[1]
* SYSTEM_INTID[31:0] => MASTER_IN[0]
*
* note: MASTER_IN[0] is only responsible for 32 interrupts
*
* > the value of MASTER_IN[x] is obtained by OR'ing the input interrupt lines.
*
* > the value of MASTER_OUT[x] is obtained by AND'ing MASTER_IN[x] with !MINTDIS[x].
*
* - whenever a SYSTEM_INTID is asserted, its corresponding MASTER_OUT signal will also
* be asserted, thus signaling the target processor.
*
* > please note the difference between an IRQ_STEER channel and an IRQ_STEER master output.
* An IRQ_STEER channel refers to an IRQ_STEER instance (e.g: the DSP uses IRQ_STEER channel
* 0 a.k.a instance 0). An IRQ_STEER channel has multiple master outputs. For example, in
* the case of i.MX8MP each IRQ_STEER channel has 3 master outputs since an IRQ_STEER channel
* routes 160 interrupts (32 for first master output, 64 for second master output, and 64 for
* the third master output).
*
* 3) Using Zephyr's multi-level interrupt support
* - since Zephyr supports organizing interrupts on multiple levels, we can use this to
* separate the interrupts in 2 levels:
* 1) LEVEL 1 INTERRUPTS
* - these are the interrupts that go directly to the processor (for example,
* on i.MX8MP the MU can directly assert the DSP's interrupt line 7)
*
* 2) LEVEL 2 INTERRUPTS
* - these interrupts go through IRQ_STEER and are signaled by a single
* processor interrupt line.
* - e.g: for i.MX8MP, INTID 34 (SDMA3) goes through IRQ_STEER and is signaled
* to the DSP by INTID 20 which is a direct interrupt (or LEVEL 1 interrupt).
*
* - the following diagram (1) shows the interrupt organization on i.MX8MP:
* +------------+
* | |
* SYSTEM_INTID[31:0] ------ IRQ_STEER_MASTER_0 ---- | 19 |
* | |
* SYSTEM_INTID[95:32] ----- IRQ_STEER_MASTER_1 ---- | 20 DSP |
* | |
* SYSTEM_INTID[159:96] ---- IRQ_STEER_MASTER_2 ---- | 21 |
* | |
* +------------+
*
* - as such, asserting a system interrupt will lead to asserting its corresponding DSP
* interrupt line (for example, if system interrupt 34 is asserted, that would lead to
* interrupt 20 being asserted)
*
* - in the above diagram, SYSTEM_INTID[x] are LEVEL 2 interrupts, while 19, 20, and 21 are
* LEVEL 1 interrupts.
*
* - INTID 19 is the parent of SYSTEM_INTID[31:0] and so on.
*
* > before going into how the INTIDs are encoded, we need to distinguish between 3 types of
* INTIDs:
* 1) System INTIDs
* - these are the values that can be found in NXP's TRMs for different
* SoCs (usually they have the same IDs as the GIC SPIs)
* - for example, INTID 34 is a system INTID for SDMA3 (i.MX8MP).
*
* 2) Zephyr INTIDs
* - these are the Zephyr-specific encodings of the system INTIDs.
* - these are used to encode multi-level interrupts (for more information
* please see [1])
* > if you need to register an interrupt dynamically, you need to use this
* encoding when specifying the interrupt.
*
* 3) DTS INTIDs
* - these are the encodings of the system INTIDs used in the DTS.
* - all of these INTIDs are relative to IRQ_STEER's MASTER_OUTs.
*
* > encoding an INTID:
* 1) SYSTEM INTID => ZEPHYR INTID
* - the following steps need to be performed:
*
* a) Find out which IRQ_STEER MASTER
* is in charge of aggregating this interrupt.
* * for instance, SYSTEM_INTID 34 (SDMA3 on i.MX8MP) is
* aggregated by MASTER 1 as depicted in diagram (1).
*
* b) After finding the MASTER aggregator, you need
* to find the corresponding parent interrupt.
* * for example, SYSTEM_INTID 34 (SDMA3 on i.MX8MP) is
* aggregated by MASTER 1, which has the parent INTID 20
* as depicted in diagram (1) => PARENT_INTID(34) = 20.
*
* c) Find the INTID relative to the MASTER aggregator. This is done
* by subtracting the number of interrupts each of the previous
* master aggregators is in charge of. If the master aggregator is
* MASTER 0 then RELATIVE_INTID=SYSTEM_INTID.
* * for example, SYSTEM_ID 34 is aggregated by MASTER 1.
* As such, we need to subtract 32 from 34 (because the
* previous master - MASTER 0 - is in charge of aggregating
* 32 interrupts) => RELATIVE_INTID(34) = 2.
*
* * generally speaking, RELATIVE_INTID can be computed using
* the following formula (assuming SYSTEM_INTID belongs to
* MASTER y):
* RELATIVE_INTID(x) = x -
* \sum{i=0}^{y - 1} GET_MASTER_INT_NUM(i)
* where:
* 1) GET_MASTER_INT_NUM(x) computes the number of
* interrupts master x aggregates
* 2) x is the system interrupt
*
* * to make sure your computation is correct use the
* following restriction:
* 0 <= RELATIVE_INTID(x) < GET_MASTER_INT_NUM(y)
*
* d) To the obtained RELATIVE_INTID you need to add the value of 1,
* left shift the result by the number of bits used to encode the
* level 1 interrupts (see [1] for details) and OR the parent ID.
* * for example, RELATIVE_INTID(34) = 2 (i.MX8MP),
* PARENT_INTID(34) = 20 => ZEPHYR_INTID = ((2 + 1) << 8) | 20
*
* * generally speaking, ZEPHYR_INTID can be computed using
* the following formula:
* ZEPHYR_INTID(x) = ((RELATIVE_INTID(x) + 1) <<
* NUM_LVL1_BITS) | PARENT_INTID(x)
* where:
* 1) RELATIVE_INTID(x) computes the relative INTID
* of system interrupt x (step c).
*
* 2) NUM_LVL1_BITS is the number of bits used to
* encode level 1 interrupts.
*
* 3) PARENT_INTID(x) computes the parent INTID of a
* system interrupt x (step b)
*
* - all of these steps are performed by to_zephyr_irq().
* > for interrupts aggregated by MASTER 0 you may skip step c) as
* RELATIVE_INTID(x) = x.
*
* 2) SYSTEM INTID => DTS INTID
* - for this you just have to compute RELATIVE_INTID as described above in
* step c).
* - for example, if an IP uses INTID 34 you'd write its interrupts property
* as follows (i.MX8MP):
* interrupts = <&master1 2>;
*
* 4) Notes and comments
* > PLEASE DON'T MISTAKE THE ZEPHYR MULTI-LEVEL INTERRUPT ORGANIZATION WITH THE XTENSA ONE.
* THEY ARE DIFFERENT THINGS.
*
* [1]: https://docs.zephyrproject.org/latest/kernel/services/interrupts.html#multi-level-interrupt-handling
*/
#include <zephyr/device.h>
#include <zephyr/irq.h>
#include <fsl_irqsteer.h>
#include <zephyr/cache.h>
#include "sw_isr_common.h"
/* used for driver binding */
#define DT_DRV_COMPAT nxp_irqsteer_intc
/* macros used for DTS parsing */
#define _IRQSTEER_REGISTER_DISPATCHER(node_id) \
IRQ_CONNECT(DT_IRQN(node_id), \
DT_IRQ(node_id, priority), \
irqsteer_isr_dispatcher, \
&dispatchers[DT_REG_ADDR(node_id)], \
0)
#define _IRQSTEER_DECLARE_DISPATCHER(node_id) \
{ \
.dev = DEVICE_DT_GET(DT_PARENT(node_id)), \
.master_index = DT_REG_ADDR(node_id), \
.irq = DT_IRQN(node_id), \
}
#define IRQSTEER_DECLARE_DISPATCHERS(parent_id)\
DT_FOREACH_CHILD_STATUS_OKAY_SEP(parent_id, _IRQSTEER_DECLARE_DISPATCHER, (,))
#define IRQSTEER_REGISTER_DISPATCHERS(parent_id)\
DT_FOREACH_CHILD_STATUS_OKAY_SEP(parent_id, _IRQSTEER_REGISTER_DISPATCHER, (;))
/* utility macros */
#define UINT_TO_IRQSTEER(x) ((IRQSTEER_Type *)(x))
struct irqsteer_config {
uint32_t regmap_phys;
uint32_t regmap_size;
struct irqsteer_dispatcher *dispatchers;
};
struct irqsteer_dispatcher {
const struct device *dev;
/* which set of interrupts is the dispatcher in charge of? */
uint32_t master_index;
/* which interrupt line is the dispatcher tied to? */
uint32_t irq;
};
static struct irqsteer_dispatcher dispatchers[] = {
IRQSTEER_DECLARE_DISPATCHERS(DT_NODELABEL(irqsteer))
};
/* used to convert system INTID to zephyr INTID */
static int to_zephyr_irq(uint32_t regmap, uint32_t irq,
struct irqsteer_dispatcher *dispatcher)
{
int i, idx;
idx = irq;
for (i = dispatcher->master_index - 1; i >= 0; i--) {
idx -= IRQSTEER_GetMasterIrqCount(UINT_TO_IRQSTEER(regmap), i);
}
return irq_to_level_2(idx) | dispatcher->irq;
}
/* used to convert master-relative INTID to system INTID */
static int to_system_irq(uint32_t regmap, int irq, int master_index)
{
int i;
for (i = master_index - 1; i >= 0; i--) {
irq += IRQSTEER_GetMasterIrqCount(UINT_TO_IRQSTEER(regmap), i);
}
return irq;
}
/* used to convert zephyr INTID to system INTID */
static int from_zephyr_irq(uint32_t regmap, uint32_t irq, uint32_t master_index)
{
int i, idx;
idx = irq;
for (i = 0; i < master_index; i++) {
idx += IRQSTEER_GetMasterIrqCount(UINT_TO_IRQSTEER(regmap), i);
}
return idx;
}
void z_soc_irq_enable_disable(uint32_t irq, bool enable)
{
uint32_t parent_irq;
int i, system_irq, level2_irq;
const struct irqsteer_config *cfg;
if (irq_get_level(irq) == 1) {
/* LEVEL 1 interrupts are DSP direct */
if (enable) {
xtensa_irq_enable(XTENSA_IRQ_NUMBER(irq));
} else {
xtensa_irq_disable(XTENSA_IRQ_NUMBER(irq));
}
return;
}
parent_irq = irq_parent_level_2(irq);
level2_irq = irq_from_level_2(irq);
/* find dispatcher responsible for this interrupt */
for (i = 0; i < ARRAY_SIZE(dispatchers); i++) {
if (dispatchers[i].irq != parent_irq) {
continue;
}
cfg = dispatchers[i].dev->config;
system_irq = from_zephyr_irq(cfg->regmap_phys, level2_irq,
dispatchers[i].master_index);
if (enable) {
IRQSTEER_EnableInterrupt(UINT_TO_IRQSTEER(cfg->regmap_phys),
system_irq);
} else {
IRQSTEER_DisableInterrupt(UINT_TO_IRQSTEER(cfg->regmap_phys),
system_irq);
}
return;
}
}
void z_soc_irq_enable(uint32_t irq)
{
z_soc_irq_enable_disable(irq, true);
}
void z_soc_irq_disable(uint32_t irq)
{
z_soc_irq_enable_disable(irq, false);
}
int z_soc_irq_is_enabled(unsigned int irq)
{
uint32_t parent_irq;
int i, system_irq, level2_irq;
const struct irqsteer_config *cfg;
if (irq_get_level(irq) == 1) {
/* LEVEL 1 interrupts are DSP direct */
return xtensa_irq_is_enabled(XTENSA_IRQ_NUMBER(irq));
}
parent_irq = irq_parent_level_2(irq);
level2_irq = irq_from_level_2(irq);
/* find dispatcher responsible for this interrupt */
for (i = 0; i < ARRAY_SIZE(dispatchers); i++) {
if (dispatchers[i].irq != parent_irq) {
continue;
}
cfg = dispatchers[i].dev->config;
system_irq = from_zephyr_irq(cfg->regmap_phys, level2_irq,
dispatchers[i].master_index);
return IRQSTEER_InterruptIsEnabled(UINT_TO_IRQSTEER(cfg->regmap_phys), system_irq);
}
return false;
}
static void irqsteer_isr_dispatcher(const void *data)
{
struct irqsteer_dispatcher *dispatcher;
const struct irqsteer_config *cfg;
uint32_t table_idx;
int system_irq, zephyr_irq, i;
uint64_t status;
dispatcher = (struct irqsteer_dispatcher *)data;
cfg = dispatcher->dev->config;
/* fetch master interrupts status */
status = IRQSTEER_GetMasterInterruptsStatus(UINT_TO_IRQSTEER(cfg->regmap_phys),
dispatcher->master_index);
for (i = 0; status; i++) {
/* if bit 0 is set then that means relative INTID i is asserted */
if (status & 1) {
/* convert master-relative INTID to a system INTID */
system_irq = to_system_irq(cfg->regmap_phys, i,
dispatcher->master_index);
/* convert system INTID to a Zephyr INTID */
zephyr_irq = to_zephyr_irq(cfg->regmap_phys, system_irq, dispatcher);
/* compute index in the SW ISR table */
table_idx = z_get_sw_isr_table_idx(zephyr_irq);
/* call child's ISR */
_sw_isr_table[table_idx].isr(_sw_isr_table[table_idx].arg);
}
status >>= 1;
}
}
static void irqsteer_enable_dispatchers(const struct device *dev)
{
int i;
struct irqsteer_dispatcher *dispatcher;
const struct irqsteer_config *cfg;
cfg = dev->config;
for (i = 0; i < ARRAY_SIZE(dispatchers); i++) {
dispatcher = &dispatchers[i];
IRQSTEER_EnableMasterInterrupt(UINT_TO_IRQSTEER(cfg->regmap_phys),
dispatcher->irq);
xtensa_irq_enable(XTENSA_IRQ_NUMBER(dispatcher->irq));
}
}
static int irqsteer_init(const struct device *dev)
{
IRQSTEER_REGISTER_DISPATCHERS(DT_NODELABEL(irqsteer));
/* enable all dispatchers */
irqsteer_enable_dispatchers(dev);
return 0;
}
/* TODO: do we need to add support for MMU-based SoCs? */
static struct irqsteer_config irqsteer_config = {
.regmap_phys = DT_REG_ADDR(DT_NODELABEL(irqsteer)),
.regmap_size = DT_REG_SIZE(DT_NODELABEL(irqsteer)),
.dispatchers = dispatchers,
};
/* assumption: only 1 IRQ_STEER instance */
DEVICE_DT_INST_DEFINE(0,
&irqsteer_init,
NULL,
NULL, &irqsteer_config,
PRE_KERNEL_1, CONFIG_INTC_INIT_PRIORITY,
NULL);