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FMC DEL 1ns 4cha - Software
Commit 50929814 authored by Alessandro Rubini's avatar Alessandro Rubini
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kernel: added interrupt support 

Signed-off-by: Alessandro Rubini's avatarAlessandro Rubini <rubini@gnudd.com>
parent a40dfd76
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Showing with 106 additions and 18 deletions
kernel/fd-irq.c
View file @ 50929814
......@@ -17,6 +17,7 @@
#include <linux/timer.h>
#include <linux/jiffies.h>
#include <linux/bitops.h>
#include <linux/gpio.h>
#include <linux/spinlock.h>
#include <linux/io.h>
......@@ -29,6 +30,7 @@
#include "fine-delay.h"
#include "hw/fd_main_regs.h"
#include "hw/fd_channel_regs.h"
#include "hw/vic_regs.h"
static int fd_sw_fifo_len = FD_SW_FIFO_LEN;
module_param_named(fifo_len, fd_sw_fifo_len, int, 0444);
......@@ -156,16 +158,18 @@ static int fd_read_hw_fifo(struct fd_dev *fd)
* We have a timer, used to poll for input samples, until the interrupt
* is there. A timer duration of 0 selects the interrupt.
*/
static int fd_timer_period_ms = 10;
static int fd_timer_period_ms = 0;
module_param_named(timer_ms, fd_timer_period_ms, int, 0444);
static int fd_timer_period_jiffies; /* converted from ms at init time */
static void fd_timer_fn(unsigned long arg)
/* This acts as either a timer or an interrupt tasklet */
static void fd_tlet(unsigned long arg)
{
struct fd_dev *fd = (void *)arg;
struct zio_channel *chan = NULL;
struct zio_device *zdev = fd->zdev;
struct fmc_device *fmc = fd->fmc;
int i;
/* Always read the hardware fifo until empty */
......@@ -179,6 +183,7 @@ static void fd_timer_fn(unsigned long arg)
goto out;
}
/* FIXME: race condition */
if (!test_bit(FD_FLAG_INPUT_READY, &fd->flags))
goto out;
......@@ -197,25 +202,67 @@ out:
pr_debug("called data_done\n");
}
mod_timer(&fd->fifo_timer, jiffies + fd_timer_period_jiffies);
if (fd_timer_period_ms)
mod_timer(&fd->fifo_timer, jiffies + fd_timer_period_jiffies);
else {
/* ack at this point, but may be redundant */
fmc->op->irq_ack(fmc);
fmc_writel(fmc, 0, FD_VIC_BASE + VIC_REG_EOIR);
}
}
int fd_irq_init(struct fd_dev *fd)
irqreturn_t fd_irq_handler(int irq, void *dev_id)
{
struct fmc_device *fmc = dev_id;
struct fd_dev *fd = fmc->mezzanine_data;
/* This is not per-device, but it works anyways */
fd_timer_period_jiffies = msecs_to_jiffies(fd_timer_period_ms);
if (fd_timer_period_ms) {
pr_info("%s: using a timer for input stamps (%i ms)\n",
KBUILD_MODNAME, fd_timer_period_ms);
} else {
pr_info("%s: NOT using interrupt (not implemented)\n",
KBUILD_MODNAME);
return -EINVAL;
if ((fd_readl(fd, FD_REG_TSBCR) & FD_TSBCR_EMPTY))
goto out_unexpected; /* bah! */
/*
* We must empty the fifo in hardware, and ack at this point.
* I used to disable_irq() and empty the fifo in the tasklet,
* but it doesn't work because the hw request is still pending
*/
while (!fd_read_hw_fifo(fd))
;
tasklet_schedule(&fd->tlet);
out_unexpected:
/*
* This may be an unexpected interrupt (it may not even be
* use, but still on the SPEC we must ack, or the system locks
* up, entering the interrupt again and again
*/
fmc->op->irq_ack(fmc);
fmc_writel(fmc, 0, FD_VIC_BASE + VIC_REG_EOIR);
return IRQ_HANDLED;
}
/* Unfortunately, on the spec this is GPIO9, i.e. IRQ(1) */
static struct fmc_gpio fd_gpio_on[] = {
{
.gpio = FMC_GPIO_IRQ(1),
.mode = GPIOF_DIR_IN,
.irqmode = IRQF_TRIGGER_RISING,
}
};
static struct fmc_gpio fd_gpio_off[] = {
{
.gpio = FMC_GPIO_IRQ(1),
.mode = GPIOF_DIR_IN,
.irqmode = 0,
}
};
/* Also, check that the sw fifo size is a power of two */
int fd_irq_init(struct fd_dev *fd)
{
struct fmc_device *fmc = fd->fmc;
uint32_t vic_ctl;
/* Check that the sw fifo size is a power of two */
if (fd_sw_fifo_len & (fd_sw_fifo_len - 1)) {
pr_err("%s: fifo len must be a power of 2 (not %d = 0x%x)\n",
KBUILD_MODNAME, fd_sw_fifo_len, fd_sw_fifo_len);
......@@ -227,16 +274,55 @@ int fd_irq_init(struct fd_dev *fd)
if (!fd->sw_fifo.t)
return -ENOMEM;
setup_timer(&fd->fifo_timer, fd_timer_fn, (unsigned long)fd);
if (fd_timer_period_ms)
fd_timer_period_jiffies = msecs_to_jiffies(fd_timer_period_ms);
/*
* According to the period, this can work with a timer (old way)
* or a custom tasklet (newer). Init both anyways, no harm is done.
*/
setup_timer(&fd->fifo_timer, fd_tlet, (unsigned long)fd);
tasklet_init(&fd->tlet, fd_tlet, (unsigned long)fd);
if (fd_timer_period_ms) {
dev_info(fd->fmc->hwdev,"Using a timer for input (%i ms)\n",
jiffies_to_msecs(fd_timer_period_jiffies));
mod_timer(&fd->fifo_timer, jiffies + fd_timer_period_jiffies);
} else {
dev_info(fd->fmc->hwdev, "Using interrupts for input\n");
fmc->op->irq_request(fmc, fd_irq_handler, "fine-delay",
IRQF_SHARED);
/* Then, configure hardware: fd, then vic, finally carrier */
fd_writel(fd, FD_EIC_IER_TS_BUF_NOTEMPTY, FD_REG_EIC_IER);
/* 4us edge emulation timer (counts in 16ns steps) */
vic_ctl = VIC_CTL_EMU_EDGE | VIC_CTL_EMU_LEN_W(4000 / 16);
fmc_writel(fmc, vic_ctl | VIC_CTL_ENABLE | VIC_CTL_POL,
FD_VIC_BASE + VIC_REG_CTL);
fmc_writel(fmc, 1, FD_VIC_BASE + VIC_REG_IER);
fmc->op->gpio_config(fmc, fd_gpio_on, ARRAY_SIZE(fd_gpio_on));
}
/* let it run... */
fd_writel(fd, FD_GCR_INPUT_EN, FD_REG_GCR);
return 0;
}
void fd_irq_exit(struct fd_dev *fd)
{
del_timer_sync(&fd->fifo_timer);
struct fmc_device *fmc = fd->fmc;
if (fd_timer_period_ms) {
del_timer_sync(&fd->fifo_timer);
} else {
/* disable interrupts: first carrier, than vic, then fd */
fmc->op->gpio_config(fmc, fd_gpio_off, ARRAY_SIZE(fd_gpio_off));
fmc_writel(fmc, 1, FD_VIC_BASE + VIC_REG_IDR);
fd_writel(fd, ~0, FD_REG_EIC_IDR);
fmc_writel(fmc, VIC_CTL_POL, FD_VIC_BASE + VIC_REG_CTL);
fmc->op->irq_free(fmc);
}
kfree(fd->sw_fifo.t);
}
kernel/fine-delay.h
View file @ 50929814
......@@ -127,6 +127,7 @@ static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
#define FD_REGS_BASE 0x80000 /* sdb_find_device(cern, f19ede1a) */
#define FD_OWREGS_BASE (FD_REGS_BASE + 0x500)
#define FD_VIC_BASE 0x90000 /* sdb_find_device(cern, 00000013) */
struct fd_calib {
int64_t frr_poly[3]; /* SY89295 delay/temp poly coeffs */
......@@ -190,6 +191,7 @@ struct fd_dev {
struct zio_device *zdev, *hwzdev;
struct timer_list fifo_timer;
struct timer_list temp_timer;
struct tasklet_struct tlet;
struct fd_calib calib;
struct fd_ch ch[FD_CH_NUMBER];
uint32_t bin;
......
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