1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* Sparx5 SoC temperature sensor driver
4 * Copyright (C) 2020 Lars Povlsen <lars.povlsen@microchip.com>
7 #include <linux/bitfield.h>
9 #include <linux/hwmon.h>
10 #include <linux/init.h>
12 #include <linux/mod_devicetable.h>
13 #include <linux/module.h>
14 #include <linux/platform_device.h>
18 #define TEMP_CFG_CYCLES GENMASK(24, 15)
19 #define TEMP_CFG_ENA BIT(0)
21 #define TEMP_STAT_VALID BIT(12)
22 #define TEMP_STAT_TEMP GENMASK(11, 0)
29 static void s5_temp_enable(struct s5_hwmon
*hwmon
)
31 u32 val
= readl(hwmon
->base
+ TEMP_CFG
);
32 u32 clk
= clk_get_rate(hwmon
->clk
) / USEC_PER_SEC
;
34 val
&= ~TEMP_CFG_CYCLES
;
35 val
|= FIELD_PREP(TEMP_CFG_CYCLES
, clk
);
38 writel(val
, hwmon
->base
+ TEMP_CFG
);
41 static int s5_read(struct device
*dev
, enum hwmon_sensor_types type
,
42 u32 attr
, int channel
, long *temp
)
44 struct s5_hwmon
*hwmon
= dev_get_drvdata(dev
);
49 case hwmon_temp_input
:
50 stat
= readl_relaxed(hwmon
->base
+ TEMP_STAT
);
51 if (!(stat
& TEMP_STAT_VALID
))
53 value
= stat
& TEMP_STAT_TEMP
;
55 * From register documentation:
56 * Temp(C) = TEMP_SENSOR_STAT.TEMP / 4096 * 352.2 - 109.4
58 value
= DIV_ROUND_CLOSEST(value
* 3522, 4096) - 1094;
60 * Scale down by 10 from above and multiply by 1000 to
61 * have millidegrees as specified by the hwmon sysfs
75 static umode_t
s5_is_visible(const void *_data
, enum hwmon_sensor_types type
,
76 u32 attr
, int channel
)
78 if (type
!= hwmon_temp
)
82 case hwmon_temp_input
:
89 static const struct hwmon_channel_info
* const s5_info
[] = {
90 HWMON_CHANNEL_INFO(chip
, HWMON_C_REGISTER_TZ
),
91 HWMON_CHANNEL_INFO(temp
, HWMON_T_INPUT
),
95 static const struct hwmon_ops s5_hwmon_ops
= {
96 .is_visible
= s5_is_visible
,
100 static const struct hwmon_chip_info s5_chip_info
= {
101 .ops
= &s5_hwmon_ops
,
105 static int s5_temp_probe(struct platform_device
*pdev
)
107 struct device
*hwmon_dev
;
108 struct s5_hwmon
*hwmon
;
110 hwmon
= devm_kzalloc(&pdev
->dev
, sizeof(*hwmon
), GFP_KERNEL
);
114 hwmon
->base
= devm_platform_ioremap_resource(pdev
, 0);
115 if (IS_ERR(hwmon
->base
))
116 return PTR_ERR(hwmon
->base
);
118 hwmon
->clk
= devm_clk_get_enabled(&pdev
->dev
, NULL
);
119 if (IS_ERR(hwmon
->clk
))
120 return PTR_ERR(hwmon
->clk
);
122 s5_temp_enable(hwmon
);
124 hwmon_dev
= devm_hwmon_device_register_with_info(&pdev
->dev
,
130 return PTR_ERR_OR_ZERO(hwmon_dev
);
133 static const struct of_device_id s5_temp_match
[] = {
134 { .compatible
= "microchip,sparx5-temp" },
137 MODULE_DEVICE_TABLE(of
, s5_temp_match
);
139 static struct platform_driver s5_temp_driver
= {
140 .probe
= s5_temp_probe
,
142 .name
= "sparx5-temp",
143 .of_match_table
= s5_temp_match
,
147 module_platform_driver(s5_temp_driver
);
149 MODULE_AUTHOR("Lars Povlsen <lars.povlsen@microchip.com>");
150 MODULE_DESCRIPTION("Sparx5 SoC temperature sensor driver");
151 MODULE_LICENSE("GPL");