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reading counter works, measured periods are plausible

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This commit is contained in:
Wolfgang Hottgenroth
2025-06-13 11:42:37 +01:00
parent 9b87645a3d
commit a6c4370fc4
1 changed files with 45 additions and 13 deletions
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58
driver/counter.c
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@ -8,6 +8,7 @@
#include <linux/spi/spi.h>
#include <linux/interrupt.h>
#include <linux/of_irq.h>
#include <linux/workqueue.h>
#include "ls7366r.h"
@ -109,7 +110,6 @@ static int read32(struct spi_device *client, u8 c, u32 *r) {
printk("counter - Error! spi_sync_transfer failed in read32\n");
return ret;
}
printk("counter - Info! rx_buf: %02x %02x %02x %02x %02x\n", rx_buf[0], rx_buf[1], rx_buf[2], rx_buf[3], rx_buf[4]);
*r = ((u32)rx_buf[1] << 24) | ((u32)rx_buf[2] << 16) | ((u32)rx_buf[3] << 8) | ((u32)rx_buf[4]);
return 0;
}
@ -128,14 +128,11 @@ static int read8(struct spi_device *client, u8 c, u8 *r) {
printk("counter - Error! spi_sync_transfer failed in read8\n");
return ret;
}
printk("counter - Info! rx_buf: %02x %02x\n", rx_buf[0], rx_buf[1]);
*r = rx_buf[1];
return 0;
}
static struct of_device_id ls7366r_driver_ids[] = {
{
.compatible = "hottis,ls7366r",
@ -159,6 +156,8 @@ static struct spi_driver ls7366r_driver = {
},
};
static struct spi_device *spi_client;
static int dt_ls7366r_probe(struct spi_device *client) {
printk("counter - ls7366r probing\n");
@ -190,16 +189,12 @@ static int dt_ls7366r_probe(struct spi_device *client) {
printk("counter - Error! read8 failed in probe\n");
return ret;
}
printk("counter - Info! x = %02x\n", x);
u32 y;
ret = read32(client, CMD_RD | REG_OTR, &y);
if (ret < 0) {
printk("counter - Error! read32 failed in probe\n");
return ret;
if (x != MDR0_ILO) {
printk("counter - Error! failed to initialize counter\n");
return -1;
}
printk("counter - Info! y = %d\n", y);
spi_client = client;
return 0;
}
@ -233,9 +228,41 @@ static struct platform_driver interrupt_driver = {
static struct gpio_desc *counter_interrupt;
static int irq_number;
// workqueue
struct counter_irq_data {
struct work_struct work;
u64 timestamp;
struct spi_device *client;
u64 last_timestamp;
u32 last_value;
};
static struct counter_irq_data counter_irq_wq_data;
static void counter_worker(struct work_struct *work) {
struct counter_irq_data *data = container_of(work, struct counter_irq_data, work);
u64 ts = data->timestamp;
u32 counter_value;
int ret = read32(data->client, CMD_RD | REG_OTR, &counter_value);
if (ret < 0) {
printk("counter - Error! read32 failed in counter_worker\n");
return;
}
if (data->last_value) {
u32 period = counter_value - data->last_value;
u64 duration = ts - data->last_timestamp;
printk("counter - Info! ts = %llu, duration = %llu, period = %u\n", ts, duration, period);
}
data->last_value = counter_value;
data->last_timestamp = ts;
}
// ISR
static irqreturn_t counter_isr(int irq, void *dev_id) {
printk("counter - interrupt received\n");
counter_irq_wq_data.timestamp = ktime_get();
schedule_work(&counter_irq_wq_data.work);
return IRQ_HANDLED;
}
@ -244,6 +271,11 @@ static int dt_interrupt_probe(struct platform_device *pdev) {
printk("counter - interrupt probing\n");
INIT_WORK(&counter_irq_wq_data.work, counter_worker);
counter_irq_wq_data.client = spi_client;
counter_irq_wq_data.last_value = 0;
counter_irq_wq_data.last_timestamp = 0;
counter_interrupt = gpiod_get(dev, "intr", GPIOD_IN);
if (IS_ERR(counter_interrupt)) {
printk("counter - Error! Could not setup the GPIO intr\n");