/* * R-Car THS/TSC thermal sensor driver * * Copyright (C) 2012 Renesas Solutions Corp. * Kuninori Morimoto * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; version 2 of the License. * * 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. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ #include #include #include #include #include #include #include #include #define THSCR 0x2c #define THSSR 0x30 /* THSCR */ #define CPTAP 0xf /* THSSR */ #define CTEMP 0x3f struct rcar_thermal_priv { void __iomem *base; struct device *dev; spinlock_t lock; u32 comp; }; /* * basic functions */ static u32 rcar_thermal_read(struct rcar_thermal_priv *priv, u32 reg) { unsigned long flags; u32 ret; spin_lock_irqsave(&priv->lock, flags); ret = ioread32(priv->base + reg); spin_unlock_irqrestore(&priv->lock, flags); return ret; } #if 0 /* no user at this point */ static void rcar_thermal_write(struct rcar_thermal_priv *priv, u32 reg, u32 data) { unsigned long flags; spin_lock_irqsave(&priv->lock, flags); iowrite32(data, priv->base + reg); spin_unlock_irqrestore(&priv->lock, flags); } #endif static void rcar_thermal_bset(struct rcar_thermal_priv *priv, u32 reg, u32 mask, u32 data) { unsigned long flags; u32 val; spin_lock_irqsave(&priv->lock, flags); val = ioread32(priv->base + reg); val &= ~mask; val |= (data & mask); iowrite32(val, priv->base + reg); spin_unlock_irqrestore(&priv->lock, flags); } /* * zone device functions */ static int rcar_thermal_get_temp(struct thermal_zone_device *zone, unsigned long *temp) { struct rcar_thermal_priv *priv = zone->devdata; int val, min, max, tmp; tmp = -200; /* default */ while (1) { if (priv->comp < 1 || priv->comp > 12) { dev_err(priv->dev, "THSSR invalid data (%d)\n", priv->comp); priv->comp = 4; /* for next thermal */ return -EINVAL; } /* * THS comparator offset and the reference temperature * * Comparator | reference | Temperature field * offset | temperature | measurement * | (degrees C) | (degrees C) * -------------+---------------+------------------- * 1 | -45 | -45 to -30 * 2 | -30 | -30 to -15 * 3 | -15 | -15 to 0 * 4 | 0 | 0 to +15 * 5 | +15 | +15 to +30 * 6 | +30 | +30 to +45 * 7 | +45 | +45 to +60 * 8 | +60 | +60 to +75 * 9 | +75 | +75 to +90 * 10 | +90 | +90 to +105 * 11 | +105 | +105 to +120 * 12 | +120 | +120 to +135 */ /* calculate thermal limitation */ min = (priv->comp * 15) - 60; max = min + 15; /* * we need to wait 300us after changing comparator offset * to get stable temperature. * see "Usage Notes" on datasheet */ rcar_thermal_bset(priv, THSCR, CPTAP, priv->comp); udelay(300); /* calculate current temperature */ val = rcar_thermal_read(priv, THSSR) & CTEMP; val = (val * 5) - 65; dev_dbg(priv->dev, "comp/min/max/val = %d/%d/%d/%d\n", priv->comp, min, max, val); /* * If val is same as min/max, then, * it should try again on next comparator. * But the val might be correct temperature. * Keep it on "tmp" and compare with next val. */ if (tmp == val) break; if (val <= min) { tmp = min; priv->comp--; /* try again */ } else if (val >= max) { tmp = max; priv->comp++; /* try again */ } else { tmp = val; break; } } *temp = tmp; return 0; } static struct thermal_zone_device_ops rcar_thermal_zone_ops = { .get_temp = rcar_thermal_get_temp, }; /* * platform functions */ static int rcar_thermal_probe(struct platform_device *pdev) { struct thermal_zone_device *zone; struct rcar_thermal_priv *priv; struct resource *res; int ret; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res) { dev_err(&pdev->dev, "Could not get platform resource\n"); return -ENODEV; } priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); if (!priv) { dev_err(&pdev->dev, "Could not allocate priv\n"); return -ENOMEM; } priv->comp = 4; /* basic setup */ priv->dev = &pdev->dev; spin_lock_init(&priv->lock); priv->base = devm_ioremap_nocache(&pdev->dev, res->start, resource_size(res)); if (!priv->base) { dev_err(&pdev->dev, "Unable to ioremap thermal register\n"); ret = -ENOMEM; goto error_free_priv; } zone = thermal_zone_device_register("rcar_thermal", 0, 0, priv, &rcar_thermal_zone_ops, 0, 0); if (IS_ERR(zone)) { dev_err(&pdev->dev, "thermal zone device is NULL\n"); ret = PTR_ERR(zone); goto error_iounmap; } platform_set_drvdata(pdev, zone); dev_info(&pdev->dev, "proved\n"); return 0; error_iounmap: devm_iounmap(&pdev->dev, priv->base); error_free_priv: devm_kfree(&pdev->dev, priv); return ret; } static int rcar_thermal_remove(struct platform_device *pdev) { struct thermal_zone_device *zone = platform_get_drvdata(pdev); struct rcar_thermal_priv *priv = zone->devdata; thermal_zone_device_unregister(zone); platform_set_drvdata(pdev, NULL); devm_iounmap(&pdev->dev, priv->base); devm_kfree(&pdev->dev, priv); return 0; } static struct platform_driver rcar_thermal_driver = { .driver = { .name = "rcar_thermal", }, .probe = rcar_thermal_probe, .remove = rcar_thermal_remove, }; module_platform_driver(rcar_thermal_driver); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("R-Car THS/TSC thermal sensor driver"); MODULE_AUTHOR("Kuninori Morimoto ");