Re: [PATCH 3/4] thermal: ti-soc-thermal: Simplify polling with iopoll

From: Adam Ford
Date: Sat Feb 06 2021 - 08:03:15 EST


On Fri, Feb 5, 2021 at 7:45 AM Tony Lindgren <tony@xxxxxxxxxxx> wrote:
>
> We can use iopoll for checking the EOCZ (end of conversion) bit. And with
> this we now also want to handle the timeout errors properly.
>
> For omap3, we need about 1.2ms for the single mode sampling to wait for
> EOCZ down, so let's use 1.5ms timeout there. Waiting for sampling to start
> is faster and we can use 1ms timeout.
>
> Cc: Adam Ford <aford173@xxxxxxxxx>
> Cc: Carl Philipp Klemm <philipp@xxxxxxxx>
> Cc: Eduardo Valentin <edubezval@xxxxxxxxx>
> Cc: H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>
> Cc: Merlijn Wajer <merlijn@xxxxxxxxxx>
> Cc: Pavel Machek <pavel@xxxxxx>
> Cc: Peter Ujfalusi <peter.ujfalusi@xxxxxxxxx>
> Cc: Sebastian Reichel <sre@xxxxxxxxxx>
> Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>

For the series,

Tested-by: Adam Ford <aford173@xxxxxxxxx> #logicpd-torpedo-37xx-devkit

> ---
> drivers/thermal/ti-soc-thermal/ti-bandgap.c | 30 ++++++++++-----------
> 1 file changed, 14 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/thermal/ti-soc-thermal/ti-bandgap.c b/drivers/thermal/ti-soc-thermal/ti-bandgap.c
> --- a/drivers/thermal/ti-soc-thermal/ti-bandgap.c
> +++ b/drivers/thermal/ti-soc-thermal/ti-bandgap.c
> @@ -15,7 +15,6 @@
> #include <linux/kernel.h>
> #include <linux/interrupt.h>
> #include <linux/clk.h>
> -#include <linux/delay.h>
> #include <linux/gpio/consumer.h>
> #include <linux/platform_device.h>
> #include <linux/err.h>
> @@ -27,6 +26,7 @@
> #include <linux/of_platform.h>
> #include <linux/of_irq.h>
> #include <linux/io.h>
> +#include <linux/iopoll.h>
> #include <linux/cpu_pm.h>
> #include <linux/device.h>
> #include <linux/pm_runtime.h>
> @@ -604,7 +604,9 @@ static int
> ti_bandgap_force_single_read(struct ti_bandgap *bgp, int id)
> {
> struct temp_sensor_registers *tsr = bgp->conf->sensors[id].registers;
> - u32 counter;
> + void __iomem *temp_sensor_ctrl = bgp->base + tsr->temp_sensor_ctrl;
> + int error;
> + u32 val;
>
> /* Select continuous or single conversion mode */
> if (TI_BANDGAP_HAS(bgp, MODE_CONFIG)) {
> @@ -619,26 +621,22 @@ ti_bandgap_force_single_read(struct ti_bandgap *bgp, int id)
> RMW_BITS(bgp, id, temp_sensor_ctrl, bgap_soc_mask, 1);
>
> /* Wait for EOCZ going up */
> - counter = 1000;
> - while (--counter) {
> - if (ti_bandgap_readl(bgp, tsr->temp_sensor_ctrl) &
> - tsr->bgap_eocz_mask)
> - break;
> - udelay(1);
> - }
> + error = readl_poll_timeout_atomic(temp_sensor_ctrl, val,
> + val & tsr->bgap_eocz_mask,
> + 1, 1000);
> + if (error)
> + dev_warn(bgp->dev, "eocz timed out waiting high\n");
>
> /* Clear Start of Conversion if available */
> RMW_BITS(bgp, id, temp_sensor_ctrl, bgap_soc_mask, 0);
> }
>
> /* Wait for EOCZ going down, always needed even if no bgap_soc_mask */
> - counter = 1000;
> - while (--counter) {
> - if (!(ti_bandgap_readl(bgp, tsr->temp_sensor_ctrl) &
> - tsr->bgap_eocz_mask))
> - break;
> - udelay(1);
> - }
> + error = readl_poll_timeout_atomic(temp_sensor_ctrl, val,
> + !(val & tsr->bgap_eocz_mask),
> + 1, 1500);
> + if (error)
> + dev_warn(bgp->dev, "eocz timed out waiting low\n");
>
> return 0;
> }
> --
> 2.30.0