Hi Keerthy,
On Wed, Aug 31, 2011 at 7:25 PM, Keerthy <[email protected]> wrote:
> The device file adds the device support for OMAP4
> on die temperature sensor.
>
> Signed-off-by: Keerthy <[email protected]>
> Cc: [email protected]
> ---
> arch/arm/mach-omap2/Makefile | 1 +
> arch/arm/mach-omap2/temp_sensor_device.c | 188
> ++++++++++++++++++++++++++++++
> arch/arm/plat-omap/Kconfig | 12 ++
> 3 files changed, 201 insertions(+), 0 deletions(-)
> create mode 100644 arch/arm/mach-omap2/temp_sensor_device.c
>
> diff --git a/arch/arm/mach-omap2/Makefile b/arch/arm/mach-omap2/Makefile
> index 2d5d981..5812fb4 100644
> --- a/arch/arm/mach-omap2/Makefile
> +++ b/arch/arm/mach-omap2/Makefile
> @@ -18,6 +18,7 @@ obj-$(CONFIG_ARCH_OMAP4) += prm44xx.o $(hwmod-common)
>
> obj-$(CONFIG_OMAP_MCBSP) += mcbsp.o
>
> +obj-$(CONFIG_OMAP_TEMP_SENSOR) += temp_sensor_device.o
> obj-$(CONFIG_TWL4030_CORE) += omap_twl.o
>
> # SMP support ONLY available for OMAP4
> diff --git a/arch/arm/mach-omap2/temp_sensor_device.c
> b/arch/arm/mach-omap2/temp_sensor_device.c
> new file mode 100644
> index 0000000..12d6789
> --- /dev/null
> +++ b/arch/arm/mach-omap2/temp_sensor_device.c
> @@ -0,0 +1,188 @@
> +/*
> + * OMAP on die Temperature sensor device file
> + *
> + * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
> + * Author: J Keerthy <[email protected]>
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * version 2 as published by the Free Software Foundation.
> + *
> + * 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., 51 Franklin St, Fifth Floor, Boston, MA
> + * 02110-1301 USA
> + *
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/slab.h>
> +#include <linux/io.h>
> +#include <linux/mutex.h>
> +#include <linux/idr.h>
> +#include <plat/omap_device.h>
> +#include "pm.h"
> +#include <plat/temperature_sensor.h>
> +
> +
> +int omap_temp_sensor_device_idle(struct omap_device *od)
> +{
> + struct omap_temp_sensor_registers *registers;
> + struct resource *mem;
> + void __iomem *phy_base;
> + unsigned long timeout;
> + u32 ret = 0, temp;
> +
> + mem = platform_get_resource(&od->pdev, IORESOURCE_MEM, 0);
> + if (!mem) {
> + dev_err(&od->pdev.dev, "no mem resource\n");
> + ret = -EINVAL;
> + goto plat_res_err;
> + }
> +
> + phy_base = ioremap(mem->start, resource_size(mem));
> +
> + if (!phy_base) {
> + dev_err(&od->pdev.dev, "ioremap failed\n");
> + ret = -ENOMEM;
> + goto plat_res_err;
> + }
> +
> + if (!strcmp(od->hwmods[0]->dev_attr, "mpu"))
> + registers = &omap_mpu_temp_sensor_registers;
> +
> + temp = __raw_readl(phy_base + registers->temp_sensor_ctrl);
> + temp |= registers->bgap_tempsoff_mask;
> +
> + /* BGAP_TEMPSOFF should be set to 1 before gating clock */
> + __raw_writel(temp, phy_base + registers->temp_sensor_ctrl);
> + temp = __raw_readl(phy_base + registers->bgap_status);
> + timeout = jiffies + msecs_to_jiffies(5);
> +
> + /* wait till the clean stop bit is set or till the timeout expires */
> + while (!(temp | registers->status_clean_stop_mask) &&
> + !(time_after(jiffies, timeout))) {
> + temp = __raw_readl(phy_base + registers->bgap_status);
> + usleep_range(500, 2000);
> + }
> +
> + if (time_after(jiffies, timeout))
> + dev_err(&od->pdev.dev, "Clean stop bit not set\n");
> +
> + ret = omap_device_idle_hwmods(od);
> + iounmap(phy_base);
> +plat_res_err:
> + return ret;
> +}
> +
> +int omap_temp_sensor_device_activate(struct omap_device *od)
> +{
> + struct omap_temp_sensor_registers *registers;
> + struct resource *mem;
> + void __iomem *phy_base;
> + u32 ret = 0, temp;
> +
> + ret = omap_device_enable_hwmods(od);
> + if (ret < 0)
> + return ret;
> + mem = platform_get_resource(&od->pdev, IORESOURCE_MEM, 0);
> + if (!mem) {
> + dev_err(&od->pdev.dev, "no mem resource\n");
> + return -EINVAL;
> + }
> +
> + phy_base = ioremap(mem->start, resource_size(mem));
> + if (!phy_base) {
> + dev_err(&od->pdev.dev, "ioremap failed\n");
> + ret = -ENOMEM;
> + goto plat_res_err;
> + }
> +
> + if (!strcmp(od->hwmods[0]->dev_attr, "mpu"))
> + registers = &omap_mpu_temp_sensor_registers;
> +
> + temp = __raw_readl(phy_base + registers->temp_sensor_ctrl);
> + temp &= ~(registers->bgap_tempsoff_mask);
> + /* BGAP_TEMPSOFF should be reset to 0 */
> + __raw_writel(temp,
> + phy_base + registers->temp_sensor_ctrl);
> + iounmap(phy_base);
> +
> +plat_res_err:
> + return ret;
> +}
I do not think it is a good thing to ioremap and iounmap the resource
registers every time you need to access the device.
That should be gone in init/deinit functions instead.
Regards,
Jean
> +
> +static struct omap_device_pm_latency omap_temp_sensor_latency[] = {
> + {
> + .deactivate_func = omap_temp_sensor_device_idle,
> + .activate_func = omap_temp_sensor_device_activate,
> + .flags = OMAP_DEVICE_LATENCY_AUTO_ADJUST,
> + }
> +};
> +
> +static DEFINE_IDR(temp_sensor_device_idr);
> +
> +static int temp_sensor_dev_init(struct omap_hwmod *oh, void *user)
> +{
> + struct omap_temp_sensor_pdata *temp_sensor_pdata;
> + struct omap_device *od;
> + struct omap_temp_sensor_dev_attr *temp_sensor_dev_attr;
> + int ret = 0;
> + int num;
> +
> + temp_sensor_pdata =
> + kzalloc(sizeof(*temp_sensor_pdata), GFP_KERNEL);
> + if (!temp_sensor_pdata) {
> + dev_err(&oh->od->pdev.dev,
> + "Unable to allocate memory for temp sensor pdata\n");
> + return -ENOMEM;
> + }
> +
> + ret = idr_pre_get(&temp_sensor_device_idr, GFP_KERNEL);
> + if (ret < 0)
> + goto fail_id;
> + ret = idr_get_new(&temp_sensor_device_idr, temp_sensor_pdata, &num);
> + if (ret < 0)
> + goto fail_id;
> +
> + temp_sensor_dev_attr = oh->dev_attr;
> + if (!strcmp(temp_sensor_dev_attr->name, "mpu")) {
> + temp_sensor_pdata->registers =
> &omap_mpu_temp_sensor_registers;
> + } else {
> + dev_warn(&oh->od->pdev.dev, "Invalid device attribute\n");
> + ret = -EINVAL;
> + goto fail_id;
> + }
> +
> + od = omap_device_build("omap_temp_sensor", num,
> + oh, temp_sensor_pdata, sizeof(*temp_sensor_pdata),
> + omap_temp_sensor_latency,
> + ARRAY_SIZE(omap_temp_sensor_latency), 0);
> +
> + if (IS_ERR(od)) {
> + dev_warn(&oh->od->pdev.dev,
> + "Could not build omap_device for %s\n", oh->name);
> + ret = PTR_ERR(od);
> + }
> +
> +fail_id:
> + kfree(temp_sensor_pdata);
> +
> + return ret;
> +}
> +
> +int __init omap_devinit_temp_sensor(void)
> +{
> + if (!cpu_is_omap446x())
> + return 0;
> +
> + return omap_hwmod_for_each_by_class("temperature_sensor",
> + temp_sensor_dev_init, NULL);
> +}
> +
> +arch_initcall(omap_devinit_temp_sensor);
> diff --git a/arch/arm/plat-omap/Kconfig b/arch/arm/plat-omap/Kconfig
> index 6e6735f..8fd8e80 100644
> --- a/arch/arm/plat-omap/Kconfig
> +++ b/arch/arm/plat-omap/Kconfig
> @@ -115,6 +115,18 @@ config OMAP_MCBSP
> Say Y here if you want support for the OMAP Multichannel
> Buffered Serial Port.
>
> +config OMAP_TEMP_SENSOR
> + bool "OMAP Temp Sensor Support"
> + depends on ARCH_OMAP
> + default n
> + help
> + Say Y here if you want support for the temp sensor
> + on OMAP4460.
> +
> + This provides the temperature of the MPU
> + subsystem. Only one instance of on die temperature
> + sensor is present.
> +
> config OMAP_MBOX_FWK
> tristate "Mailbox framework support"
> depends on ARCH_OMAP
> --
> 1.7.0.4
>
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