26d9339db0
If the driver is built as a module, autoload won't work because the module alias information is not filled. So user-space can't match the registered device with the corresponding module. Export the module alias information using the MODULE_DEVICE_TABLE() macro. Before this patch: $ modinfo drivers/thermal/tango_thermal.ko | grep alias $ After this patch: $ modinfo drivers/thermal/tango_thermal.ko | grep alias alias: of:N*T*Csigma,smp8758-thermalC* alias: of:N*T*Csigma,smp8758-thermal Acked-by: Marc Gonzalez <marc_gonzalez@sigmadesigns.com> Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com> Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
125 lines
3.1 KiB
C
125 lines
3.1 KiB
C
#include <linux/io.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/module.h>
|
|
#include <linux/thermal.h>
|
|
#include <linux/platform_device.h>
|
|
|
|
/*
|
|
* According to a data sheet draft, "this temperature sensor uses a bandgap
|
|
* type of circuit to compare a voltage which has a negative temperature
|
|
* coefficient with a voltage that is proportional to absolute temperature.
|
|
* A resistor bank allows 41 different temperature thresholds to be selected
|
|
* and the logic output will then indicate whether the actual die temperature
|
|
* lies above or below the selected threshold."
|
|
*/
|
|
|
|
#define TEMPSI_CMD 0
|
|
#define TEMPSI_RES 4
|
|
#define TEMPSI_CFG 8
|
|
|
|
#define CMD_OFF 0
|
|
#define CMD_ON 1
|
|
#define CMD_READ 2
|
|
|
|
#define IDX_MIN 15
|
|
#define IDX_MAX 40
|
|
|
|
struct tango_thermal_priv {
|
|
void __iomem *base;
|
|
int thresh_idx;
|
|
};
|
|
|
|
static bool temp_above_thresh(void __iomem *base, int thresh_idx)
|
|
{
|
|
writel(CMD_READ | thresh_idx << 8, base + TEMPSI_CMD);
|
|
usleep_range(10, 20);
|
|
writel(CMD_READ | thresh_idx << 8, base + TEMPSI_CMD);
|
|
|
|
return readl(base + TEMPSI_RES);
|
|
}
|
|
|
|
static int tango_get_temp(void *arg, int *res)
|
|
{
|
|
struct tango_thermal_priv *priv = arg;
|
|
int idx = priv->thresh_idx;
|
|
|
|
if (temp_above_thresh(priv->base, idx)) {
|
|
/* Search upward by incrementing thresh_idx */
|
|
while (idx < IDX_MAX && temp_above_thresh(priv->base, ++idx))
|
|
cpu_relax();
|
|
idx = idx - 1; /* always return lower bound */
|
|
} else {
|
|
/* Search downward by decrementing thresh_idx */
|
|
while (idx > IDX_MIN && !temp_above_thresh(priv->base, --idx))
|
|
cpu_relax();
|
|
}
|
|
|
|
*res = (idx * 9 / 2 - 38) * 1000; /* millidegrees Celsius */
|
|
priv->thresh_idx = idx;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct thermal_zone_of_device_ops ops = {
|
|
.get_temp = tango_get_temp,
|
|
};
|
|
|
|
static void tango_thermal_init(struct tango_thermal_priv *priv)
|
|
{
|
|
writel(0, priv->base + TEMPSI_CFG);
|
|
writel(CMD_ON, priv->base + TEMPSI_CMD);
|
|
}
|
|
|
|
static int tango_thermal_probe(struct platform_device *pdev)
|
|
{
|
|
struct resource *res;
|
|
struct tango_thermal_priv *priv;
|
|
struct thermal_zone_device *tzdev;
|
|
|
|
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
|
|
if (!priv)
|
|
return -ENOMEM;
|
|
|
|
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
priv->base = devm_ioremap_resource(&pdev->dev, res);
|
|
if (IS_ERR(priv->base))
|
|
return PTR_ERR(priv->base);
|
|
|
|
platform_set_drvdata(pdev, priv);
|
|
priv->thresh_idx = IDX_MIN;
|
|
tango_thermal_init(priv);
|
|
|
|
tzdev = devm_thermal_zone_of_sensor_register(&pdev->dev, 0, priv, &ops);
|
|
return PTR_ERR_OR_ZERO(tzdev);
|
|
}
|
|
|
|
static int __maybe_unused tango_thermal_resume(struct device *dev)
|
|
{
|
|
tango_thermal_init(dev_get_drvdata(dev));
|
|
return 0;
|
|
}
|
|
|
|
static SIMPLE_DEV_PM_OPS(tango_thermal_pm, NULL, tango_thermal_resume);
|
|
|
|
static const struct of_device_id tango_sensor_ids[] = {
|
|
{
|
|
.compatible = "sigma,smp8758-thermal",
|
|
},
|
|
{ /* sentinel */ }
|
|
};
|
|
MODULE_DEVICE_TABLE(of, tango_sensor_ids);
|
|
|
|
static struct platform_driver tango_thermal_driver = {
|
|
.probe = tango_thermal_probe,
|
|
.driver = {
|
|
.name = "tango-thermal",
|
|
.of_match_table = tango_sensor_ids,
|
|
.pm = &tango_thermal_pm,
|
|
},
|
|
};
|
|
|
|
module_platform_driver(tango_thermal_driver);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Sigma Designs");
|
|
MODULE_DESCRIPTION("Tango temperature sensor");
|