Re: [PATCH v3 04/11] thermal: armada: Rationalize register accesses

Baruch Siach
2017-12-15T08:56:29Z

Hi Miquèl,

On Thu, Dec 14, 2017 at 11:30:04AM +0100, Miquel Raynal wrote:
> Bindings were incomplete for a long time by only exposing one of the two
> available control registers. To ease the migration to the full bindings
> (already in use for the Armada 375 SoC), rename the pointers for
> clarification. This way, it will only be needed to add another pointer
> to access the other control register when the time comes.
>
> This avoids dangerous situations where the offset 0 of the control
> area can be either one register or the other depending on the bindings
> used. After this change, device trees of other SoCs could be migrated to
> the "full" bindings if they may benefit from features from the
> unaccessible register, without any change in the driver.
>
> Signed-off-by: Miquel Raynal <miquel.raynal@free-electrons.com>
> ---
> drivers/thermal/armada_thermal.c | 86 +++++++++++++++++++++++++---------------
> 1 file changed, 55 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/thermal/armada_thermal.c b/drivers/thermal/armada_thermal.c
> index 26698f2d3ca7..e5b184cee79b 100644
> --- a/drivers/thermal/armada_thermal.c
> +++ b/drivers/thermal/armada_thermal.c
> @@ -39,12 +39,21 @@
> #define A375_HW_RESETn BIT(8)
> #define A380_HW_RESET BIT(8)
>
> +/* Legacy bindings */
> +#define LEGACY_CONTROL_MEM_LEN 0x4
> +
> +/* Current bindings with the 2 control registers under the same memory area */
> +#define LEGACY_CONTROL1_OFFSET 0x0
> +#define CONTROL0_OFFSET 0x0
> +#define CONTROL1_OFFSET 0x4
> +
> struct armada_thermal_data;
>
> /* Marvell EBU Thermal Sensor Dev Structure */
> struct armada_thermal_priv {
> - void __iomem *sensor;
> - void __iomem *control;
> + void __iomem *status;
> + void __iomem *control0;
> + void __iomem *control1;

The 'status' -> 'sensor' rename is not mentioned in the commit log. I'd say it
is a matter for a separate patch.

Otherwise, good cleanup.

baruch

> struct armada_thermal_data *data;
> };
>
> @@ -71,45 +80,45 @@ struct armada_thermal_data {
> static void armadaxp_init_sensor(struct platform_device *pdev,
> struct armada_thermal_priv *priv)
> {
> - unsigned long reg;
> + u32 reg;
>
> - reg = readl_relaxed(priv->control);
> + reg = readl_relaxed(priv->control1);
> reg |= PMU_TDC0_OTF_CAL_MASK;
> - writel(reg, priv->control);
> + writel(reg, priv->control1);
>
> /* Reference calibration value */
> reg &= ~PMU_TDC0_REF_CAL_CNT_MASK;
> reg |= (0xf1 << PMU_TDC0_REF_CAL_CNT_OFFS);
> - writel(reg, priv->control);
> + writel(reg, priv->control1);
>
> /* Reset the sensor */
> - reg = readl_relaxed(priv->control);
> - writel((reg | PMU_TDC0_SW_RST_MASK), priv->control);
> + reg = readl_relaxed(priv->control1);
> + writel((reg | PMU_TDC0_SW_RST_MASK), priv->control1);
>
> - writel(reg, priv->control);
> + writel(reg, priv->control1);
>
> /* Enable the sensor */
> - reg = readl_relaxed(priv->sensor);
> + reg = readl_relaxed(priv->status);
> reg &= ~PMU_TM_DISABLE_MASK;
> - writel(reg, priv->sensor);
> + writel(reg, priv->status);
> }
>
> static void armada370_init_sensor(struct platform_device *pdev,
> struct armada_thermal_priv *priv)
> {
> - unsigned long reg;
> + u32 reg;
>
> - reg = readl_relaxed(priv->control);
> + reg = readl_relaxed(priv->control1);
> reg |= PMU_TDC0_OTF_CAL_MASK;
> - writel(reg, priv->control);
> + writel(reg, priv->control1);
>
> /* Reference calibration value */
> reg &= ~PMU_TDC0_REF_CAL_CNT_MASK;
> reg |= (0xf1 << PMU_TDC0_REF_CAL_CNT_OFFS);
> - writel(reg, priv->control);
> + writel(reg, priv->control1);
>
> reg &= ~PMU_TDC0_START_CAL_MASK;
> - writel(reg, priv->control);
> + writel(reg, priv->control1);
>
> msleep(10);
> }
> @@ -117,37 +126,37 @@ static void armada370_init_sensor(struct platform_device *pdev,
> static void armada375_init_sensor(struct platform_device *pdev,
> struct armada_thermal_priv *priv)
> {
> - unsigned long reg;
> + u32 reg;
>
> - reg = readl(priv->control + 4);
> + reg = readl(priv->control1);
> reg &= ~(A375_UNIT_CONTROL_MASK << A375_UNIT_CONTROL_SHIFT);
> reg &= ~A375_READOUT_INVERT;
> reg &= ~A375_HW_RESETn;
>
> - writel(reg, priv->control + 4);
> + writel(reg, priv->control1);
> msleep(20);
>
> reg |= A375_HW_RESETn;
> - writel(reg, priv->control + 4);
> + writel(reg, priv->control1);
> msleep(50);
> }
>
> static void armada380_init_sensor(struct platform_device *pdev,
> struct armada_thermal_priv *priv)
> {
> - unsigned long reg = readl_relaxed(priv->control);
> + u32 reg = readl_relaxed(priv->control1);
>
> /* Reset hardware once */
> if (!(reg & A380_HW_RESET)) {
> reg |= A380_HW_RESET;
> - writel(reg, priv->control);
> + writel(reg, priv->control1);
> msleep(10);
> }
> }
>
> static bool armada_is_valid(struct armada_thermal_priv *priv)
> {
> - unsigned long reg = readl_relaxed(priv->sensor);
> + u32 reg = readl_relaxed(priv->status);
>
> return reg & priv->data->is_valid_bit;
> }
> @@ -156,7 +165,7 @@ static int armada_get_temp(struct thermal_zone_device *thermal,
> int *temp)
> {
> struct armada_thermal_priv *priv = thermal->devdata;
> - unsigned long reg;
> + u32 reg;
> unsigned long m, b, div;
>
> /* Valid check */
> @@ -166,7 +175,7 @@ static int armada_get_temp(struct thermal_zone_device *thermal,
> return -EIO;
> }
>
> - reg = readl_relaxed(priv->sensor);
> + reg = readl_relaxed(priv->status);
> reg = (reg >> priv->data->temp_shift) & priv->data->temp_mask;
>
> /* Get formula coeficients */
> @@ -253,6 +262,7 @@ MODULE_DEVICE_TABLE(of, armada_thermal_id_table);
>
> static int armada_thermal_probe(struct platform_device *pdev)
> {
> + void __iomem *control = NULL;
> struct thermal_zone_device *thermal;
> const struct of_device_id *match;
> struct armada_thermal_priv *priv;
> @@ -267,14 +277,28 @@ static int armada_thermal_probe(struct platform_device *pdev)
> return -ENOMEM;
>
> res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> - priv->sensor = devm_ioremap_resource(&pdev->dev, res);
> - if (IS_ERR(priv->sensor))
> - return PTR_ERR(priv->sensor);
> + priv->status = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(priv->status))
> + return PTR_ERR(priv->status);
>
> res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
> - priv->control = devm_ioremap_resource(&pdev->dev, res);
> - if (IS_ERR(priv->control))
> - return PTR_ERR(priv->control);
> + control = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(control))
> + return PTR_ERR(control);
> +
> + /*
> + * Legacy DT bindings only described "control1" register (also referred
> + * as "control MSB" on old documentation). New bindings cover
> + * "control0/control LSB" and "control1/control MSB" registers within
> + * the same resource, which is then of size 8 instead of 4.
> + */
> + if ((res->end - res->start) == LEGACY_CONTROL_MEM_LEN) {
> + /* ->control0 unavailable in this configuration */
> + priv->control1 = control + LEGACY_CONTROL1_OFFSET;
> + } else {
> + priv->control0 = control + CONTROL0_OFFSET;
> + priv->control1 = control + CONTROL1_OFFSET;
> + }
>
> priv->data = (struct armada_thermal_data *)match->data;
> priv->data->init_sensor(pdev, priv);

--
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