/*
*
* Programmable Interrupt Controller functions for the Freescale MPC52xx.
*
* Copyright (C) 2008 Secret Lab Technologies Ltd.
* Copyright (C) 2006 bplan GmbH
* Copyright (C) 2004 Sylvain Munaut <[email protected]>
* Copyright (C) 2003 Montavista Software, Inc
*
* Based on the code from the 2.4 kernel by
* Dale Farnsworth <[email protected]> and Kent Borg.
*
* This file is licensed under the terms of the GNU General Public License
* version 2. This program is licensed "as is" without any warranty of any
* kind, whether express or implied.
*
*/
/*
* This is the device driver for the MPC5200 interrupt controller.
*
* hardware overview
* -----------------
* The MPC5200 interrupt controller groups the all interrupt sources into
* three groups called 'critical', 'main', and 'peripheral'. The critical
* group has 3 irqs, External IRQ0, slice timer 0 irq, and wake from deep
* sleep. Main group include the other 3 external IRQs, slice timer 1, RTC,
* gpios, and the general purpose timers. Peripheral group contains the
* remaining irq sources from all of the on-chip peripherals (PSCs, Ethernet,
* USB, DMA, etc).
*
* virqs
* -----
* The Linux IRQ subsystem requires that each irq source be assigned a
* system wide unique IRQ number starting at 1 (0 means no irq). Since
* systems can have multiple interrupt controllers, the virtual IRQ (virq)
* infrastructure lets each interrupt controller to define a local set
* of IRQ numbers and the virq infrastructure maps those numbers into
* a unique range of the global IRQ# space.
*
* To define a range of virq numbers for this controller, this driver first
* assigns a number to each of the irq groups (called the level 1 or L1
* value). Within each group individual irq sources are also assigned a
* number, as defined by the MPC5200 user guide, and refers to it as the
* level 2 or L2 value. The virq number is determined by shifting up the
* L1 value by MPC52xx_IRQ_L1_OFFSET and ORing it with the L2 value.
*
* For example, the TMR0 interrupt is irq 9 in the main group. The
* virq for TMR0 is calculated by ((1 << MPC52xx_IRQ_L1_OFFSET) | 9).
*
* The observant reader will also notice that this driver defines a 4th
* interrupt group called 'bestcomm'. The bestcomm group isn't physically
* part of the MPC5200 interrupt controller, but it is used here to assign
* a separate virq number for each bestcomm task (since any of the 16
* bestcomm tasks can cause the bestcomm interrupt to be raised). When a
* bestcomm interrupt occurs (peripheral group, irq 0) this driver determines
* which task needs servicing and returns the irq number for that task. This
* allows drivers which use bestcomm to define their own interrupt handlers.
*
* irq_chip structures
* -------------------
* For actually manipulating IRQs (masking, enabling, clearing, etc) this
* driver defines four separate 'irq_chip' structures, one for the main
* group, one for the peripherals group, one for the bestcomm group and one
* for external interrupts. The irq_chip structures provide the hooks needed
* to manipulate each IRQ source, and since each group is has a separate set
* of registers for controlling the irq, it makes sense to divide up the
* hooks along those lines.
*
* You'll notice that there is not an irq_chip for the critical group and
* you'll also notice that there is an irq_chip defined for external
* interrupts even though there is no external interrupt group. The reason
* for this is that the four external interrupts are all managed with the same
* register even though one of the external IRQs is in the critical group and
* the other three are in the main group. For this reason it makes sense for
* the 4 external irqs to be managed using a separate set of hooks. The
* reason there is no crit irq_chip is that of the 3 irqs in the critical
* group, only external interrupt is actually support at this time by this
* driver and since external interrupt is the only one used, it can just
* be directed to make use of the external irq irq_chip.
*
* device tree bindings
* --------------------
* The device tree bindings for this controller reflect the two level
* organization of irqs in the device. #interrupt-cells = <3> where the
* first cell is the group number [0..3], the second cell is the irq
* number in the group, and the third cell is the sense type (level/edge).
* For reference, the following is a list of the interrupt property values
* associated with external interrupt sources on the MPC5200 (just because
* it is non-obvious to determine what the interrupts property should be
* when reading the mpc5200 manual and it is a frequently asked question).
*
* External interrupts:
* <0 0 n> external irq0, n is sense (n=0: level high,
* <1 1 n> external irq1, n is sense n=1: edge rising,
* <1 2 n> external irq2, n is sense n=2: edge falling,
* <1 3 n> external irq3, n is sense n=3: level low)
*/
#undef DEBUG
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <asm/io.h>
#include <asm/mpc52xx.h>
/* HW IRQ mapping */
#define MPC52xx_IRQ_L1_CRIT (0)
#define MPC52xx_IRQ_L1_MAIN (1)
#define MPC52xx_IRQ_L1_PERP (2)
#define MPC52xx_IRQ_L1_SDMA (3)
#define MPC52xx_IRQ_L1_OFFSET (6)
#define MPC52xx_IRQ_L1_MASK (0x00c0)
#define MPC52xx_IRQ_L2_MASK (0x003f)
#define MPC52xx_IRQ_HIGHTESTHWIRQ (0xd0)
/* MPC5200 device tree match tables */
static const struct of_device_id mpc52xx_pic_ids[] __initconst = {
{ .compatible = "fsl,mpc5200-pic", },
{ .compatible = "mpc5200-pic", },
{}
};
static const struct of_device_id mpc52xx_sdma_ids[] __initconst = {
{ .compatible = "fsl,mpc5200-bestcomm", },
{ .compatible = "mpc5200-bestcomm", },
{}
};
static struct mpc52xx_intr __iomem *intr;
static struct mpc52xx_sdma __iomem *sdma;
static struct irq_domain *mpc52xx_irqhost = NULL;
static unsigned char mpc52xx_map_senses[4] = {
IRQ_TYPE_LEVEL_HIGH,
IRQ_TYPE_EDGE_RISING,
IRQ_TYPE_EDGE_FALLING,
IRQ_TYPE_LEVEL_LOW,
};
/* Utility functions */
static inline void io_be_setbit(u32 __iomem *addr, int bitno)
{
out_be32(addr, in_be32(addr) | (1 << bitno));
}
static inline void io_be_clrbit(u32 __iomem *addr, int bitno)
{
out_be32(addr, in_be32(addr) & ~(1 << bitno));
}
/*
* IRQ[0-3] interrupt irq_chip
*/
static void mpc52xx_extirq_mask(struct irq_data *d)
{
int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK;
io_be_clrbit(&intr->ctrl, 11 - l2irq);
}
static void mpc52xx_extirq_unmask(struct irq_data *d)
{
int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK;
io_be_setbit(&intr->ctrl, 11 - l2irq);
}
static void mpc52xx_extirq_ack(struct irq_data *d)
{
int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK;
io_be_setbit(&intr->ctrl, 27-l2irq);
}
static int mpc52xx_extirq_set_type(struct irq_data *d, unsigned int flow_type)
{
u32 ctrl_reg, type;
int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK;
void *handler = handle_level_irq;
pr_debug("%s: irq=%x. l2=%d flow_type=%d\n", __func__,
(int) irqd_to_hwirq(d), l2irq, flow_type);
switch (flow_type) {
case IRQF_TRIGGER_HIGH: type = 0; break;
case IRQF_TRIGGER_RISING: type = 1; handler = handle_edge_irq; break;
case IRQF_TRIGGER_FALLING: type = 2; handler = handle_edge_irq; break;
case IRQF_TRIGGER_LOW: type = 3; break;
default:
type = 0;
}
ctrl_reg = in_be32(&intr->ctrl);
ctrl_reg &= ~(0x3 << (22 - (l2irq * 2)));
ctrl_reg |= (type << (22 - (l2irq * 2)));
out_be32(&intr->ctrl, ctrl_reg);
irq_set_handler_locked(d, handler);
return 0;
}
static struct irq_chip mpc52xx_extirq_irqchip = {
.name = "MPC52xx External",
.irq_mask = mpc52xx_extirq_mask,
.irq_unmask = mpc52xx_extirq_unmask,
.irq_ack = mpc52xx_extirq_ack,
.irq_set_type = mpc52xx_extirq_set_type,
};
/*
* Main interrupt irq_chip
*/
static int mpc52xx_null_set_type(struct irq_data *d, unsigned int flow_type)
{
return 0; /* Do nothing so that the sense mask will get updated */
}
static void mpc52xx_main_mask(struct irq_data *d)
{
int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK;
io_be_setbit(&intr->main_mask, 16 - l2irq);
}
static void mpc52xx_main_unmask(struct irq_data *d)
{
int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK;
io_be_clrbit(&intr->main_mask, 16 - l2irq);
}
static struct irq_chip mpc52xx_main_irqchip = {
.name = "MPC52xx Main",
.irq_mask = mpc52xx_main_mask,
.irq_mask_ack = mpc52xx_main_mask,
.irq_unmask = mpc52xx_main_unmask,
.irq_set_type = mpc52xx_null_set_type,
};
/*
* Peripherals interrupt irq_chip
*/
static void mpc52xx_periph_mask(struct irq_data *d)
{
int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK;
io_be_setbit(&intr->per_mask, 31 - l2irq);
}
static void mpc52xx_periph_unmask(struct irq_data *d)
{
int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK;
io_be_clrbit(&intr->per_mask, 31 - l2irq);
}
static struct irq_chip mpc52xx_periph_irqchip = {
.name = "MPC52xx Peripherals",
.irq_mask = mpc52xx_periph_mask,
.irq_mask_ack = mpc52xx_periph_mask,
.irq_unmask = mpc52xx_periph_unmask,
.irq_set_type = mpc52xx_null_set_type,
};
/*
* SDMA interrupt irq_chip
*/
static void mpc52xx_sdma_mask(struct irq_data *d)
{
int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK;
io_be_setbit(&sdma->IntMask, l2irq);
}
static void mpc52xx_sdma_unmask(struct irq_data *d)
{
int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK;
io_be_clrbit(&sdma->IntMask, l2irq);
}
static void mpc52xx_sdma_ack(struct irq_data *d)
{
int l2irq = irqd_to_hwirq(d) & MPC52xx_IRQ_L2_MASK;
out_be32(&sdma->IntPend, 1 << l2irq);
}
static struct irq_chip mpc52xx_sdma_irqchip = {
.name = "MPC52xx SDMA",
.irq_mask = mpc52xx_sdma_mask,
.irq_unmask = mpc52xx_sdma_unmask,
.irq_ack = mpc52xx_sdma_ack,
.irq_set_type = mpc52xx_null_set_type,
};
/**
* mpc52xx_is_extirq - Returns true if hwirq number is for an external IRQ
*/
static int mpc52xx_is_extirq(int l1, int l2)
{
return ((l1 == 0) && (l2 == 0)) ||
((l1 == 1) && (l2 >= 1) && (l2 <= 3));
}
/**
* mpc52xx_irqhost_xlate - translate virq# from device tree interrupts property
*/
static int mpc52xx_irqhost_xlate(struct irq_domain *h, struct device_node *ct,
const u32 *intspec, unsigned int intsize,
irq_hw_number_t *out_hwirq,
unsigned int *out_flags)
{
int intrvect_l1;
int intrvect_l2;
int intrvect_type;
int intrvect_linux;
if (intsize != 3)
return -1;
intrvect_l1 = (int)intspec[0];
intrvect_l2 = (int)intspec[1];
intrvect_type = (int)intspec[2] & 0x3;
intrvect_linux = (intrvect_l1 << MPC52xx_IRQ_L1_OFFSET) &
MPC52xx_IRQ_L1_MASK;
intrvect_linux |= intrvect_l2 & MPC52xx_IRQ_L2_MASK;
*out_hwirq = intrvect_linux;
*out_flags = IRQ_TYPE_LEVEL_LOW;
if (mpc52xx_is_extirq(intrvect_l1, intrvect_l2))
*out_flags = mpc52xx_map_senses[intrvect_type];
pr_debug("return %x, l1=%d, l2=%d\n", intrvect_linux, intrvect_l1,
intrvect_l2);
return 0;
}
/**
* mpc52xx_irqhost_map - Hook to map from virq to an irq_chip structure
*/
static int mpc52xx_irqhost_map(struct irq_domain *h, unsigned int virq,
irq_hw_number_t irq)
{
int l1irq;
int l2irq;
struct irq_chip *irqchip;
void *hndlr;
int type;
u32 reg;
l1irq = (irq & MPC52xx_IRQ_L1_MASK) >> MPC52xx_IRQ_L1_OFFSET;
l2irq = irq & MPC52xx_IRQ_L2_MASK;
/*
* External IRQs are handled differently by the hardware so they are
* handled by a dedicated irq_chip structure.
*/
if (mpc52xx_is_extirq(l1irq, l2irq)) {
reg = in_be32(&intr->ctrl);
type = mpc52xx_map_senses[(reg >> (22 - l2irq * 2)) & 0x3];
if ((type == IRQ_TYPE_EDGE_FALLING) ||
(type == IRQ_TYPE_EDGE_RISING))
hndlr = handle_edge_irq;
else
hndlr = handle_level_irq;
irq_set_chip_and_handler(virq, &mpc52xx_extirq_irqchip, hndlr);
pr_debug("%s: External IRQ%i virq=%x, hw=%x. type=%x\n",
__func__, l2irq, virq, (int)irq, type);
return 0;
}
/* It is an internal SOC irq. Choose the correct irq_chip */
switch (l1irq) {
case MPC52xx_IRQ_L1_MAIN: irqchip = &mpc52xx_main_irqchip; break;
case MPC52xx_IRQ_L1_PERP: irqchip = &mpc52xx_periph_irqchip; break;
case MPC52xx_IRQ_L1_SDMA: irqchip = &mpc52xx_sdma_irqchip; break;
case MPC52xx_IRQ_L1_CRIT:
pr_warn("%s: Critical IRQ #%d is unsupported! Nopping it.\n",
__func__, l2irq);
irq_set_chip(virq, &no_irq_chip);
return 0;
}
irq_set_chip_and_handler(virq, irqchip, handle_level_irq);
pr_debug("%s: virq=%x, l1=%i, l2=%i\n", __func__, virq, l1irq, l2irq);
return 0;
}
static const struct irq_domain_ops mpc52xx_irqhost_ops = {
.xlate = mpc52xx_irqhost_xlate,
.map = mpc52xx_irqhost_map,
};
/**
* mpc52xx_init_irq - Initialize and register with the virq subsystem
*
* Hook for setting up IRQs on an mpc5200 system. A pointer to this function
* is to be put into the machine definition structure.
*
* This function searches the device tree for an MPC5200 interrupt controller,
* initializes it, and registers it with the virq subsystem.
*/
void __init mpc52xx_init_irq(void)
{
u32 intr_ctrl;
struct device_node *picnode;
struct device_node *np;
/* Remap the necessary zones */
picnode = of_find_matching_node(NULL, mpc52xx_pic_ids);
intr = of_iomap(picnode, 0);
if (!intr)
panic(__FILE__ ": find_and_map failed on 'mpc5200-pic'. "
"Check node !");
np = of_find_matching_node(NULL, mpc52xx_sdma_ids);
sdma = of_iomap(np, 0);
of_node_put(np);
if (!sdma)
panic(__FILE__ ": find_and_map failed on 'mpc5200-bestcomm'. "
"Check node !");
pr_debug("MPC5200 IRQ controller mapped to 0x%p\n", intr);
/* Disable all interrupt sources. */
out_be32(&sdma->IntPend, 0xffffffff); /* 1 means clear pending */
out_be32(&sdma->IntMask, 0xffffffff); /* 1 means disabled */
out_be32(&intr->per_mask, 0x7ffffc00); /* 1 means disabled */
out_be32(&intr->main_mask, 0x00010fff); /* 1 means disabled */
intr_ctrl = in_be32(&intr->ctrl);
intr_ctrl &= 0x00ff0000; /* Keeps IRQ[0-3] config */
intr_ctrl |= 0x0f000000 | /* clear IRQ 0-3 */
0x00001000 | /* MEE master external enable */
0x00000000 | /* 0 means disable IRQ 0-3 */
0x00000001; /* CEb route critical normally */
out_be32(&intr->ctrl, intr_ctrl);
/* Zero a bunch of the priority settings. */
out_be32(&intr->per_pri1, 0);
out_be32(&intr->per_pri2, 0);
out_be32(&intr->per_pri3, 0);
out_be32(&intr->main_pri1, 0);
out_be32(&intr->main_pri2, 0);
/*
* As last step, add an irq host to translate the real
* hw irq information provided by the ofw to linux virq
*/
mpc52xx_irqhost = irq_domain_add_linear(picnode,
MPC52xx_IRQ_HIGHTESTHWIRQ,
&mpc52xx_irqhost_ops, NULL);
if (!mpc52xx_irqhost)
panic(__FILE__ ": Cannot allocate the IRQ host\n");
irq_set_default_host(mpc52xx_irqhost);
pr_info("MPC52xx PIC is up and running!\n");
}
/**
* mpc52xx_get_irq - Get pending interrupt number hook function
*
* Called by the interrupt handler to determine what IRQ handler needs to be
* executed.
*
* Status of pending interrupts is determined by reading the encoded status
* register. The encoded status register has three fields; one for each of the
* types of interrupts defined by the controller - 'critical', 'main' and
* 'peripheral'. This function reads the status register and returns the IRQ
* number associated with the highest priority pending interrupt. 'Critical'
* interrupts have the highest priority, followed by 'main' interrupts, and
* then 'peripheral'.
*
* The mpc5200 interrupt controller can be configured to boost the priority
* of individual 'peripheral' interrupts. If this is the case then a special
* value will appear in either the crit or main fields indicating a high
* or medium priority peripheral irq has occurred.
*
* This function checks each of the 3 irq request fields and returns the
* first pending interrupt that it finds.
*
* This function also identifies a 4th type of interrupt; 'bestcomm'. Each
* bestcomm DMA task can raise the bestcomm peripheral interrupt. When this
* occurs at task-specific IRQ# is decoded so that each task can have its
* own IRQ handler.
*/
unsigned int mpc52xx_get_irq(void)
{
u32 status;
int irq;
status = in_be32(&intr->enc_status);
if (status & 0x00000400) { /* critical */
irq = (status >> 8) & 0x3;
if (irq == 2) /* high priority peripheral */
goto peripheral;
irq |= (MPC52xx_IRQ_L1_CRIT << MPC52xx_IRQ_L1_OFFSET);
} else if (status & 0x00200000) { /* main */
irq = (status >> 16) & 0x1f;
if (irq == 4) /* low priority peripheral */
goto peripheral;
irq |= (MPC52xx_IRQ_L1_MAIN << MPC52xx_IRQ_L1_OFFSET);
} else if (status & 0x20000000) { /* peripheral */
peripheral:
irq = (status >> 24) & 0x1f;
if (irq == 0) { /* bestcomm */
status = in_be32(&sdma->IntPend);
irq = ffs(status) - 1;
irq |= (MPC52xx_IRQ_L1_SDMA << MPC52xx_IRQ_L1_OFFSET);
} else {
irq |= (MPC52xx_IRQ_L1_PERP << MPC52xx_IRQ_L1_OFFSET);
}
} else {
return 0;
}
return irq_linear_revmap(mpc52xx_irqhost, irq);
}
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