Hi Martin,
> kernel@xxxxxxxxxxxxxxxx hat am 19. September 2016 um 10:59 geschrieben:
>
>
> From: Martin Sperl <kernel@xxxxxxxxxxxxxxxx>
>
> Add basic thermal driver for bcm2835 SOC.
>
> This driver currently relies on the firmware setting up the
> tsense HW block and does not set it up itself.
>
> Signed-off-by: Martin Sperl <kernel@xxxxxxxxxxxxxxxx>
> Acked-by: Eric Anholt <eric@xxxxxxxxxx>
>
> ChangeLog:
> V1 -> V2: added specific settings depending on compatiblity
> added trip point based on register
> setting up ctrl-register if HW is not enabled by firmware
> as per recommendation of Eric (untested)
> check that clock frequency is in range
> (1.9 - 5MHz - as per comment in clk-bcm2835.c)
> V2 -> V4: moved back to thermal (not using bcm sub-directory)
> set polling interval to 1second (was 0ms, so interrupt driven)
> V5 -> V6: added correct depends in KConfig
> removed defined default for RESET_DELAY
> removed obvious comments
> clarify HW setup comments if not set up by FW already
> move clk_prepare_enable to an earlier stage and add error handling
> clarify warning when TS-clock runs out of recommended range
> clk_disable_unprepare added in bcm2835_thermal_remove
> added comment on recommended temperature ranges for SOC
> ---
> drivers/thermal/Kconfig | 8 +
> drivers/thermal/Makefile | 1 +
> drivers/thermal/bcm2835_thermal.c | 340
> ++++++++++++++++++++++++++++++++++++++
> 3 files changed, 349 insertions(+)
> create mode 100644 drivers/thermal/bcm2835_thermal.c
>
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index 2d702ca..6489723 100644
> --- a/drivers/thermal/Kconfig
> +++ b/drivers/thermal/Kconfig
> @@ -399,4 +399,12 @@ config GENERIC_ADC_THERMAL
> to this driver. This driver reports the temperature by reading ADC
> channel and converts it to temperature based on lookup table.
>
> +config BCM2835_THERMAL
> + tristate "Thermal sensors on bcm2835 SoC"
> + depends on ARCH_BCM2835 || ARCH_BCM2836 || ARCH_BCM2837 || COMPILE_TEST
AFAIK there are no ARCH_BCM2836 or ARCH_BCM2837
After fixing that, you can add my ACK.
> + depends on OF
> + depends on HAS_IOMEM
> + help
> + Support for thermal sensors on Broadcom bcm2835 SoCs.
> +
> ...
> +
> +static const struct of_device_id bcm2835_thermal_of_match_table[];
> +static int bcm2835_thermal_probe(struct platform_device *pdev)
> +{
> + const struct of_device_id *match;
> + struct thermal_zone_device *tz;
> + struct bcm2835_thermal_data *data;
> + struct resource *res;
> + int err;
> + u32 val;
> + unsigned long rate;
> +
> + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
> + if (!data)
> + return -ENOMEM;
> +
> + match = of_match_device(bcm2835_thermal_of_match_table,
> + &pdev->dev);
> + if (!match)
> + return -EINVAL;
> + data->info = match->data;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + data->regs = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(data->regs)) {
> + err = PTR_ERR(data->regs);
> + dev_err(&pdev->dev, "Could not get registers: %d\n", err);
> + return err;
> + }
> +
> + data->clk = devm_clk_get(&pdev->dev, NULL);
> + if (IS_ERR(data->clk)) {
> + err = PTR_ERR(data->clk);
> + if (err != -EPROBE_DEFER)
> + dev_err(&pdev->dev, "Could not get clk: %d\n", err);
> + return err;
> + }
> +
> + err = clk_prepare_enable(data->clk);
> + if (err)
> + return err;
> +
> + rate = clk_get_rate(data->clk);
> + if ((rate < 1920000) || (rate > 5000000))
> + dev_warn(&pdev->dev,
> + "Clock %pCn running at %pCr Hz is outside of the recommended range: 1.92
> to 5MHz\n",
> + data->clk, data->clk);
> +
> + /*
> + * right now the FW does set up the HW-block, so we are not
> + * touching the configuration registers.
> + * But if the HW is not enabled, then set it up
> + * using "sane" values used by the firmware right now.
> + */
> + val = readl(data->regs + BCM2835_TS_TSENSCTL);
> + if (!(val & BCM2835_TS_TSENSCTL_RSTB)) {
> + /* the basic required flags */
> + val = (BCM2835_TS_TSENSCTL_CTRL_DEFAULT <<
> + BCM2835_TS_TSENSCTL_CTRL_SHIFT) |
> + BCM2835_TS_TSENSCTL_REGULEN;
> +
> + /*
> + * reset delay using the current firmware value of 14
> + * - units of time are unknown.
> + */
I've have open a thread in the Raspberry Pi Forum regards to this. If i get a
positive feedback then i will send an incremental patch.
Stefan
> + val |= (14 << BCM2835_TS_TSENSCTL_RSTDELAY_SHIFT);
> +
> + /* trip_adc value from info */
> + val |= bcm2835_thermal_temp2adc(data->info,
> + data->info->trip_temp) <<
> + BCM2835_TS_TSENSCTL_THOLD_SHIFT;
> +
> + /* write the value back to the register as 2 steps */
> + writel(val, data->regs + BCM2835_TS_TSENSCTL);
> + val |= BCM2835_TS_TSENSCTL_RSTB;
> + writel(val, data->regs + BCM2835_TS_TSENSCTL);
> + }
> +
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