[PATCH V6 2/6] thermal: bcm2835: add thermal driver for bcm2835 soc
From: Stefan Wahren <hidden>
Date: 2016-09-20 17:49:00
Also in:
linux-devicetree, linux-pm
Hi Martin,
quoted hunk
kernel at martin.sperl.org hat am 19. September 2016 um 10:59 geschrieben: From: Martin Sperl <redacted> 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 <redacted> Acked-by: Eric Anholt <redacted> 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.cdiff --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); + } +