/*
* twl4030-irq.c - TWL4030/TPS659x0 irq support
*
* Copyright (C) 2005-2006 Texas Instruments, Inc.
*
* Modifications to defer interrupt handling to a kernel thread:
* Copyright (C) 2006 MontaVista Software, Inc.
*
* Based on tlv320aic23.c:
* Copyright (c) by Kai Svahn <kai.svahn@nokia.com>
*
* Code cleanup and modifications to IRQ handler.
* by syed khasim <x0khasim@ti.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/kthread.h>
#include <linux/i2c/twl4030.h>
/*
* TWL4030 IRQ handling has two stages in hardware, and thus in software.
* The Primary Interrupt Handler (PIH) stage exposes status bits saying
* which Secondary Interrupt Handler (SIH) stage is raising an interrupt.
* SIH modules are more traditional IRQ components, which support per-IRQ
* enable/disable and trigger controls; they do most of the work.
*
* These chips are designed to support IRQ handling from two different
* I2C masters. Each has a dedicated IRQ line, and dedicated IRQ status
* and mask registers in the PIH and SIH modules.
*
* We set up IRQs starting at a platform-specified base, always starting
* with PIH and the SIH for PWR_INT and then usually adding GPIO:
* base + 0 .. base + 7 PIH
* base + 8 .. base + 15 SIH for PWR_INT
* base + 16 .. base + 33 SIH for GPIO
*/
/* PIH register offsets */
#define REG_PIH_ISR_P1 0x01
#define REG_PIH_ISR_P2 0x02
#define REG_PIH_SIR 0x03 /* for testing */
/* Linux could (eventually) use either IRQ line */
static int irq_line;
struct sih {
char name[8];
u8 module; /* module id */
u8 control_offset; /* for SIH_CTRL */
bool set_cor;
u8 bits; /* valid in isr/imr */
u8 bytes_ixr; /* bytelen of ISR/IMR/SIR */
u8 edr_offset;
u8 bytes_edr; /* bytelen of EDR */
/* SIR ignored -- set interrupt, for testing only */
struct irq_data {
u8 isr_offset;
u8 imr_offset;
} mask[2];
/* + 2 bytes padding */
};
#define SIH_INITIALIZER(modname, nbits) \
.module = TWL4030_MODULE_ ## modname, \
.control_offset = TWL4030_ ## modname ## _SIH_CTRL, \
.bits = nbits, \
.bytes_ixr = DIV_ROUND_UP(nbits, 8), \
.edr_offset = TWL4030_ ## modname ## _EDR, \
.bytes_edr = DIV_ROUND_UP((2*(nbits)), 8), \
.mask = { { \
.isr_offset = TWL4030_ ## modname ## _ISR1, \
.imr_offset = TWL4030_ ## modname ## _IMR1, \
}, \
{ \
.isr_offset = TWL4030_ ## modname ## _ISR2, \
.imr_offset = TWL4030_ ## modname ## _IMR2, \
}, },
/* register naming policies are inconsistent ... */
#define TWL4030_INT_PWR_EDR TWL4030_INT_PWR_EDR1
#define TWL4030_MODULE_KEYPAD_KEYP TWL4030_MODULE_KEYPAD
#define TWL4030_MODULE_INT_PWR TWL4030_MODULE_INT
/* Order in this table matches order in PIH_ISR. That is,
* BIT(n) in PIH_ISR is sih_modules[n].
*/
static const struct sih sih_modules[6] = {
[0] = {
.name = "gpio",
.module = TWL4030_MODULE_GPIO,
.control_offset = REG_GPIO_SIH_CTRL,
.set_cor = true,
.bits = TWL4030_GPIO_MAX,
.bytes_ixr = 3,
/* Note: *all* of these IRQs default to no-trigger */
.edr_offset = REG_GPIO_EDR1,
.bytes_edr = 5,
.mask = { {
.isr_offset = REG_GPIO_ISR1A,
.imr_offset = REG_GPIO_IMR1A,
}, {
.isr_offset = REG_GPIO_ISR1B,
.imr_offset = REG_GPIO_IMR1B,
}, },
},
[1] = {
.name = "keypad",
.set_cor = true,
SIH_INITIALIZER(KEYPAD_KEYP, 4)
},
[2] = {
.name = "bci",
.module = TWL4030_MODULE_INTERRUPTS,
.control_offset = TWL4030_INTERRUPTS_BCISIHCTRL,
.bits = 12,
.bytes_ixr = 2,
.edr_offset = TWL4030_INTERRUPTS_BCIEDR1,
/* Note: most of these IRQs default to no-trigger */
.bytes_edr = 3,
.mask = { {
.isr_offset = TWL4030_INTERRUPTS_BCIISR1A,
.imr_offset = TWL4030_INTERRUPTS_BCIIMR1A,
}, {
.isr_offset = TWL4030_INTERRUPTS_BCIISR1B,
.imr_offset = TWL4030_INTERRUPTS_BCIIMR1B,
}, },
},
[3] = {
.name = "madc",
SIH_INITIALIZER(MADC, 4)
},
[4] = {
/* USB doesn't use the same SIH organization */
.name = "usb",
},
[5] = {
.name = "power",
.set_cor = true,
SIH_INITIALIZER(INT_PWR, 8)
},
/* there are no SIH modules #6 or #7 ... */
};
#undef TWL4030_MODULE_KEYPAD_KEYP
#undef TWL4030_MODULE_INT_PWR
#undef TWL4030_INT_PWR_EDR
/*----------------------------------------------------------------------*/
static unsigned twl4030_irq_base;
static struct completion irq_event;
/*
* This thread processes interrupts reported by the Primary Interrupt Handler.
*/
static int twl4030_irq_thread(void *data)
{
long irq = (long)data;
static unsigned i2c_errors;
static const unsigned max_i2c_errors = 100;
current->flags |= PF_NOFREEZE;
while (!kthread_should_stop()) {
int ret;
int module_irq;
u8 pih_isr;
/* Wait for IRQ, then read PIH irq status (also blocking) */
wait_for_completion_interruptible(&irq_event);
ret = twl4030_i2c_read_u8(TWL4030_MODULE_PIH, &pih_isr,
REG_PIH_ISR_P1);
if (ret) {
pr_warning("twl4030: I2C error %d reading PIH ISR\n",
ret);
if (++i2c_errors >= max_i2c_errors) {
printk(KERN_ERR "Maximum I2C error count"
" exceeded. Terminating %s.\n",
__func__);
break;
}
complete(&irq_event);
continue;
}
/* these handlers deal with the relevant SIH irq status */
local_irq_disable();
for (module_irq = twl4030_irq_base;
pih_isr;
pih_isr >>= 1, module_irq++) {
if (pih_isr & 0x1) {
struct irq_desc *d = irq_to_desc(module_irq);
if (!d) {
pr_err("twl4030: Invalid SIH IRQ: %d\n",
module_irq);
return -EINVAL;
}
/* These can't be masked ... always warn
* if we get any surprises.
*/
if (d->status & IRQ_DISABLED)
note_interrupt(module_irq, d,
IRQ_NONE);
else
d->handle_irq(module_irq, d);
}
}
local_irq_enable();
enable_irq(irq);
}
return 0;
}
/*
* handle_twl4030_pih() is the desc->handle method for the twl4030 interrupt.
* This is a chained interrupt, so there is no desc->action method for it.
* Now we need to query the interrupt controller in the twl4030 to determine
* which module is generating the interrupt request. However, we can't do i2c
* transactions in interrupt context, so we must defer that work to a kernel
* thread. All we do here is acknowledge and mask the interrupt and wakeup
* the kernel thread.
*/
static irqreturn_t handle_twl4030_pih(int irq, void *devid)
{
/* Acknowledge, clear *AND* mask the interrupt... */
disable_irq_nosync(irq);
complete(devid);
return IRQ_HANDLED;
}
/*----------------------------------------------------------------------*/
/*
* twl4030_init_sih_modules() ... start from a known state where no
* IRQs will be coming in, and where we can quickly enable them then
* handle them as they arrive. Mask all IRQs: maybe init SIH_CTRL.
*
* NOTE: we don't touch EDR registers here; they stay with hardware
* defaults or whatever the last value was. Note that when both EDR
* bits for an IRQ are clear, that's as if its IMR bit is set...
*/
static int twl4030_init_sih_modules(unsigned line)
{
const struct sih *sih;
u8 buf[4];
int i;
int status;
/* line 0 == int1_n signal; line 1 == int2_n signal */
if (line > 1)
return -EINVAL;
irq_line = line;
/* disable all interrupts on our line */
memset(buf, 0xff, sizeof buf);
sih = sih_modules;
for (i = 0; i < ARRAY_SIZE(sih_modules); i++, sih++) {
/* skip USB -- it's funky */
if (!sih->bytes_ixr)
continue;
status = twl4030_i2c_write(sih->module, buf,
sih->mask[line].imr_offset, sih->bytes_ixr);
if (status < 0)
pr_err("twl4030: err %d initializing %s %s\n",
status, sih->name, "IMR");
/* Maybe disable "exclusive" mode; buffer second pending irq;
* set Clear-On-Read (COR) bit.
*
* NOTE that sometimes COR polarity is documented as being
* inverted: for MADC and BCI, COR=1 means "clear on write".
* And for PWR_INT it's not documented...
*/
if (sih->set_cor) {
status = twl4030_i2c_write_u8(sih->module,
TWL4030_SIH_CTRL_COR_MASK,
sih->control_offset);
if (status < 0)
pr_err("twl4030: err %d initializing %s %s\n",
status, sih->name, "SIH_CTRL");
}
}
sih = sih_modules;
for (i = 0; i < ARRAY_SIZE(sih_modules); i++, sih++) {
u8 rxbuf[4];
int j;
/* skip USB */
if (!sih->bytes_ixr)
continue;
/* Clear pending interrupt status. Either the read was
* enough, or we need to write those bits. Repeat, in
* case an IRQ is pending (PENDDIS=0) ... that's not
* uncommon with PWR_INT.PWRON.
*/
for (j = 0; j < 2; j++) {
status = twl4030_i2c_read(sih->module, rxbuf,
sih->mask[line].isr_offset, sih->bytes_ixr);
if (status < 0)
pr_err("twl4030: err %d initializing %s %s\n",
status, sih->name, "ISR");
if (!sih->set_cor)
status = twl4030_i2c_write(sih->module, buf,
sih->mask[line].isr_offset,
sih->bytes_ixr);
/* else COR=1 means read sufficed.
* (for most SIH modules...)
*/
}
}
return 0;
}
static inline void activate_irq(int irq)
{
#ifdef CONFIG_ARM
/* ARM requires an extra step to clear IRQ_NOREQUEST, which it
* sets on behalf of every irq_chip. Also sets IRQ_NOPROBE.
*/
set_irq_flags(irq, IRQF_VALID);
#else
/* same effect on other architectures */
set_irq_noprobe(irq);
#endif
}
/*----------------------------------------------------------------------*/
static DEFINE_SPINLOCK(sih_agent_lock);
static struct workqueue_struct *wq;
struct sih_agent {
int irq_base;
const struct sih *sih;
u32 imr;
bool imr_change_pending;
struct work_struct mask_work;
u32 edge_change;
struct work_struct edge_work;
};
static void twl4030_sih_do_mask(struct work_struct *work)
{
struct sih_agent *agent;
const struct sih *sih;
union {
u8 bytes[4];
u32 word;
} imr;
int status;
agent = container_of(work, struct sih_agent, mask_work);
/* see what work we have */
spin_lock_irq(&sih_agent_lock);
if (agent->imr_change_pending) {
sih = agent->sih;
/* byte[0] gets overwritten as we write ... */
imr.word = cpu_to_le32(agent->imr << 8);
agent->imr_change_pending = false;
} else
sih = NULL;
spin_unlock_irq(&sih_agent_lock);
if (!sih)
return;
/* write the whole mask ... simpler than subsetting it */
status = twl4030_i2c_write(sih->module, imr.bytes,
sih->mask[irq_line].imr_offset, sih->bytes_ixr);
if (status)
pr_err("twl4030: %s, %s --> %d\n", __func__,
"write", status);
}
static void twl4030_sih_do_edge(struct work_struct *work)
{
struct sih_agent *agent;
const struct sih *sih;
u8 bytes[6];
u32 edge_change;
int status;
agent = container_of(work, struct sih_agent, edge_work);
/* see what work we have */
spin_lock_irq(&sih_agent_lock);
edge_change = agent->edge_change;
agent->edge_change = 0;;
sih = edge_change ? agent->sih : NULL;
spin_unlock_irq(&sih_agent_lock);
if (!sih)
return;
/* Read, reserving first byte for write scratch. Yes, this
* could be cached for some speedup ... but be careful about
* any processor on the other IRQ line, EDR registers are
* shared.
*/
status = twl4030_i2c_read(sih->module, bytes + 1,
sih->edr_offset, sih->bytes_edr);
if (status) {
pr_err("twl4030: %s, %s --> %d\n", __func__,
"read", status);
return;
}
/* Modify only the bits we know must change */
while (edge_change) {
int i = fls(edge_change) - 1;
struct irq_desc *d = irq_to_desc(i + agent->irq_base);
int byte = 1 + (i >> 2);
int off = (i & 0x3) * 2;
if (!d) {
pr_err("twl4030: Invalid IRQ: %d\n",
i + agent->irq_base);
return;
}
bytes[byte] &= ~(0x03 << off);
spin_lock_irq(&d->lock);
if (d->status & IRQ_TYPE_EDGE_RISING)
bytes[byte] |= BIT(off + 1);
if (d->status & IRQ_TYPE_EDGE_FALLING)
bytes[byte] |= BIT(off + 0);
spin_unlock_irq(&d->lock);
edge_change &= ~BIT(i);
}
/* Write */
status = twl4030_i2c_write(sih->module, bytes,
sih->edr_offset, sih->bytes_edr);
if (status)
pr_err("twl4030: %s, %s --> %d\n", __func__,
"write", status);
}
/*----------------------------------------------------------------------*/
/*
* All irq_chip methods get issued from code holding irq_desc[irq].lock,
* which can't perform the underlying I2C operations (because they sleep).
* So we must hand them off to a thread (workqueue) and cope with asynch
* completion, potentially including some re-ordering, of these requests.
*/
static void twl4030_sih_mask(unsigned irq)
{
struct sih_agent *sih = get_irq_chip_data(irq);
unsigned long flags;
spin_lock_irqsave(&sih_agent_lock, flags);
sih->imr |= BIT(irq - sih->irq_base);
sih->imr_change_pending = true;
queue_work(wq, &sih->mask_work);
spin_unlock_irqrestore(&sih_agent_lock, flags);
}
static void twl4030_sih_unmask(unsigned irq)
{
struct sih_agent *sih = get_irq_chip_data(irq);
unsigned long flags;
spin_lock_irqsave(&sih_agent_lock, flags);
sih->imr &= ~BIT(irq - sih->irq_base);
sih->imr_change_pending = true;
queue_work(wq, &sih->mask_work);
spin_unlock_irqrestore(&sih_agent_lock, flags);
}
static int twl4030_sih_set_type(unsigned irq, unsigned trigger)
{
struct sih_agent *sih = get_irq_chip_data(irq);
struct irq_desc *desc = irq_to_desc(irq);
unsigned long flags;
if (!desc) {
pr_err("twl4030: Invalid IRQ: %d\n", irq);
return -EINVAL;
}
if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
return -EINVAL;
spin_lock_irqsave(&sih_agent_lock, flags);
if ((desc->status & IRQ_TYPE_SENSE_MASK) != trigger) {
desc->status &= ~IRQ_TYPE_SENSE_MASK;
desc->status |= trigger;
sih->edge_change |= BIT(irq - sih->irq_base);
queue_work(wq, &sih->edge_work);
}
spin_unlock_irqrestore(&sih_agent_lock, flags);
return 0;
}
static struct irq_chip twl4030_sih_irq_chip = {
.name = "twl4030",
.mask = twl4030_sih_mask,
.unmask = twl4030_sih_unmask,
.set_type = twl4030_sih_set_type,
};
/*----------------------------------------------------------------------*/
static inline int sih_read_isr(const struct sih *sih)
{
int status;
union {
u8 bytes[4];
u32 word;
} isr;
/* FIXME need retry-on-error ... */
isr.word = 0;
status = twl4030_i2c_read(sih->module, isr.bytes,
sih->mask[irq_line].isr_offset, sih->bytes_ixr);
return (status < 0) ? status : le32_to_cpu(isr.word);
}
/*
* Generic handler for SIH interrupts ... we "know" this is called
* in task context, with IRQs enabled.
*/
static void handle_twl4030_sih(unsigned irq, struct irq_desc *desc)
{
struct sih_agent *agent = get_irq_data(irq);
const struct sih *sih = agent->sih;
int isr;
/* reading ISR acks the IRQs, using clear-on-read mode */
local_irq_enable();
isr = sih_read_isr(sih);
local_irq_disable();
if (isr < 0) {
pr_err("twl4030: %s SIH, read ISR error %d\n",
sih->name, isr);
/* REVISIT: recover; eventually mask it all, etc */
return;
}
while (isr) {
irq = fls(isr);
irq--;
isr &= ~BIT(irq);
if (irq < sih->bits)
generic_handle_irq(agent->irq_base + irq);
else
pr_err("twl4030: %s SIH, invalid ISR bit %d\n",
sih->name, irq);
}
}
static unsigned twl4030_irq_next;
/* returns the first IRQ used by this SIH bank,
* or negative errno
*/
int twl4030_sih_setup(int module)
{
int sih_mod;
const struct sih *sih = NULL;
struct sih_agent *agent;
int i, irq;
int status = -EINVAL;
unsigned irq_base = twl4030_irq_next;
/* only support modules with standard clear-on-read for now */
for (sih_mod = 0, sih = sih_modules;
sih_mod < ARRAY_SIZE(sih_modules);
sih_mod++, sih++) {
if (sih->module == module && sih->set_cor) {
if (!WARN((irq_base + sih->bits) > NR_IRQS,
"irq %d for %s too big\n",
irq_base + sih->bits,
sih->name))
status = 0;
break;
}
}
if (status < 0)
return status;
agent = kzalloc(sizeof *agent, GFP_KERNEL);
if (!agent)
return -ENOMEM;
status = 0;
agent->irq_base = irq_base;
agent->sih = sih;
agent->imr = ~0;
INIT_WORK(&agent->mask_work, twl4030_sih_do_mask);
INIT_WORK(&agent->edge_work, twl4030_sih_do_edge);
for (i = 0; i < sih->bits; i++) {
irq = irq_base + i;
set_irq_chip_and_handler(irq, &twl4030_sih_irq_chip,
handle_edge_irq);
set_irq_chip_data(irq, agent);
activate_irq(irq);
}
status = irq_base;
twl4030_irq_next += i;
/* replace generic PIH handler (handle_simple_irq) */
irq = sih_mod + twl4030_irq_base;
set_irq_data(irq, agent);
set_irq_chained_handler(irq, handle_twl4030_sih);
pr_info("twl4030: %s (irq %d) chaining IRQs %d..%d\n", sih->name,
irq, irq_base, twl4030_irq_next - 1);
return status;
}
/* FIXME need a call to reverse twl4030_sih_setup() ... */
/*----------------------------------------------------------------------*/
/* FIXME pass in which interrupt line we'll use ... */
#define twl_irq_line 0
int twl_init_irq(int irq_num, unsigned irq_base, unsigned irq_end)
{
static struct irq_chip twl4030_irq_chip;
int status;
int i;
struct task_struct *task;
/*
* Mask and clear all TWL4030 interrupts since initially we do
* not have any TWL4030 module interrupt handlers present
*/
status = twl4030_init_sih_modules(twl_irq_line);
if (status < 0)
return status;
wq = create_singlethread_workqueue("twl4030-irqchip");
if (!wq) {
pr_err("twl4030: workqueue FAIL\n");
return -ESRCH;
}
twl4030_irq_base = irq_base;
/* install an irq handler for each of the SIH modules;
* clone dummy irq_chip since PIH can't *do* anything
*/
twl4030_irq_chip = dummy_irq_chip;
twl4030_irq_chip.name = "twl4030";
twl4030_sih_irq_chip.ack = dummy_irq_chip.ack;
for (i = irq_base; i < irq_end; i++) {
set_irq_chip_and_handler(i, &twl4030_irq_chip,
handle_simple_irq);
activate_irq(i);
}
twl4030_irq_next = i;
pr_info("twl4030: %s (irq %d) chaining IRQs %d..%d\n", "PIH",
irq_num, irq_base, twl4030_irq_next - 1);
/* ... and the PWR_INT module ... */
status = twl4030_sih_setup(TWL4030_MODULE_INT);
if (status < 0) {
pr_err("twl4030: sih_setup PWR INT --> %d\n", status);
goto fail;
}
/* install an irq handler to demultiplex the TWL4030 interrupt */
init_completion(&irq_event);
status = request_irq(irq_num, handle_twl4030_pih, IRQF_DISABLED,
"TWL4030-PIH", &irq_event);
if (status < 0) {
pr_err("twl4030: could not claim irq%d: %d\n", irq_num, status);
goto fail_rqirq;
}
task = kthread_run(twl4030_irq_thread, (void *)irq_num, "twl4030-irq");
if (IS_ERR(task)) {
pr_err("twl4030: could not create irq %d thread!\n", irq_num);
status = PTR_ERR(task);
goto fail_kthread;
}
return status;
fail_kthread:
free_irq(irq_num, &irq_event);
fail_rqirq:
/* clean up twl4030_sih_setup */
fail:
for (i = irq_base; i < irq_end; i++)
set_irq_chip_and_handler(i, NULL, NULL);
destroy_workqueue(wq);
wq = NULL;
return status;
}
int twl_exit_irq(void)
{
/* FIXME undo twl_init_irq() */
if (twl4030_irq_base) {
pr_err("twl4030: can't yet clean up IRQs?\n");
return -ENOSYS;
}
return 0;
}
