diff options
Diffstat (limited to 'drivers/thermal/spear_thermal.c')
| -rw-r--r-- | drivers/thermal/spear_thermal.c | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/drivers/thermal/spear_thermal.c b/drivers/thermal/spear_thermal.c new file mode 100644 index 000000000..bddb71744 --- /dev/null +++ b/drivers/thermal/spear_thermal.c @@ -0,0 +1,198 @@ +/* + * SPEAr thermal driver. + * + * Copyright (C) 2011-2012 ST Microelectronics + * Author: Vincenzo Frascino <vincenzo.frascino@st.com> + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * 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. + * + */ + +#include <linux/clk.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/of.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/thermal.h> + +#define MD_FACTOR 1000 + +/* SPEAr Thermal Sensor Dev Structure */ +struct spear_thermal_dev { + /* pointer to base address of the thermal sensor */ + void __iomem *thermal_base; + /* clk structure */ + struct clk *clk; + /* pointer to thermal flags */ + unsigned int flags; +}; + +static inline int thermal_get_temp(struct thermal_zone_device *thermal, + unsigned long *temp) +{ + struct spear_thermal_dev *stdev = thermal->devdata; + + /* + * Data are ready to be read after 628 usec from POWERDOWN signal + * (PDN) = 1 + */ + *temp = (readl_relaxed(stdev->thermal_base) & 0x7F) * MD_FACTOR; + return 0; +} + +static struct thermal_zone_device_ops ops = { + .get_temp = thermal_get_temp, +}; + +#ifdef CONFIG_PM +static int spear_thermal_suspend(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct thermal_zone_device *spear_thermal = platform_get_drvdata(pdev); + struct spear_thermal_dev *stdev = spear_thermal->devdata; + unsigned int actual_mask = 0; + + /* Disable SPEAr Thermal Sensor */ + actual_mask = readl_relaxed(stdev->thermal_base); + writel_relaxed(actual_mask & ~stdev->flags, stdev->thermal_base); + + clk_disable(stdev->clk); + dev_info(dev, "Suspended.\n"); + + return 0; +} + +static int spear_thermal_resume(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct thermal_zone_device *spear_thermal = platform_get_drvdata(pdev); + struct spear_thermal_dev *stdev = spear_thermal->devdata; + unsigned int actual_mask = 0; + int ret = 0; + + ret = clk_enable(stdev->clk); + if (ret) { + dev_err(&pdev->dev, "Can't enable clock\n"); + return ret; + } + + /* Enable SPEAr Thermal Sensor */ + actual_mask = readl_relaxed(stdev->thermal_base); + writel_relaxed(actual_mask | stdev->flags, stdev->thermal_base); + + dev_info(dev, "Resumed.\n"); + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(spear_thermal_pm_ops, spear_thermal_suspend, + spear_thermal_resume); + +static int spear_thermal_probe(struct platform_device *pdev) +{ + struct thermal_zone_device *spear_thermal = NULL; + struct spear_thermal_dev *stdev; + struct device_node *np = pdev->dev.of_node; + struct resource *res; + int ret = 0, val; + + if (!np || !of_property_read_u32(np, "st,thermal-flags", &val)) { + dev_err(&pdev->dev, "Failed: DT Pdata not passed\n"); + return -EINVAL; + } + + stdev = devm_kzalloc(&pdev->dev, sizeof(*stdev), GFP_KERNEL); + if (!stdev) + return -ENOMEM; + + /* Enable thermal sensor */ + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + stdev->thermal_base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(stdev->thermal_base)) + return PTR_ERR(stdev->thermal_base); + + stdev->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(stdev->clk)) { + dev_err(&pdev->dev, "Can't get clock\n"); + return PTR_ERR(stdev->clk); + } + + ret = clk_enable(stdev->clk); + if (ret) { + dev_err(&pdev->dev, "Can't enable clock\n"); + return ret; + } + + stdev->flags = val; + writel_relaxed(stdev->flags, stdev->thermal_base); + + spear_thermal = thermal_zone_device_register("spear_thermal", 0, 0, + stdev, &ops, NULL, 0, 0); + if (IS_ERR(spear_thermal)) { + dev_err(&pdev->dev, "thermal zone device is NULL\n"); + ret = PTR_ERR(spear_thermal); + goto disable_clk; + } + + platform_set_drvdata(pdev, spear_thermal); + + dev_info(&spear_thermal->device, "Thermal Sensor Loaded at: 0x%p.\n", + stdev->thermal_base); + + return 0; + +disable_clk: + clk_disable(stdev->clk); + + return ret; +} + +static int spear_thermal_exit(struct platform_device *pdev) +{ + unsigned int actual_mask = 0; + struct thermal_zone_device *spear_thermal = platform_get_drvdata(pdev); + struct spear_thermal_dev *stdev = spear_thermal->devdata; + + thermal_zone_device_unregister(spear_thermal); + + /* Disable SPEAr Thermal Sensor */ + actual_mask = readl_relaxed(stdev->thermal_base); + writel_relaxed(actual_mask & ~stdev->flags, stdev->thermal_base); + + clk_disable(stdev->clk); + + return 0; +} + +static const struct of_device_id spear_thermal_id_table[] = { + { .compatible = "st,thermal-spear1340" }, + {} +}; +MODULE_DEVICE_TABLE(of, spear_thermal_id_table); + +static struct platform_driver spear_thermal_driver = { + .probe = spear_thermal_probe, + .remove = spear_thermal_exit, + .driver = { + .name = "spear_thermal", + .pm = &spear_thermal_pm_ops, + .of_match_table = spear_thermal_id_table, + }, +}; + +module_platform_driver(spear_thermal_driver); + +MODULE_AUTHOR("Vincenzo Frascino <vincenzo.frascino@st.com>"); +MODULE_DESCRIPTION("SPEAr thermal driver"); +MODULE_LICENSE("GPL"); |