Re: [PATCH V4 22/30] thermal: exynos: Add support for exynos5440 TMU sensor.
From: amit daniel kachhap
Date: Tue Jun 04 2013 - 00:44:42 EST
Hi Jonghwa,
Sorry for the late reply as I was on leave.
On Sat, May 18, 2013 at 10:53 AM, <jonghwa3.lee@xxxxxxxxxxx> wrote:
> On 2013ë 05ì 14ì 18:58, Amit Daniel Kachhap wrote:
>
>> This patch modifies TMU controller to add changes needed to work with
>> exynos5440 platform. This sensor registers 3 instance of the tmu controller
>> with the thermal zone and hence reports 3 temperature output. This controller
>> supports upto five trip points. For critical threshold the driver uses the
>> core driver thermal framework for shutdown.
>>
>> Acked-by: Kukjin Kim <kgene.kim@xxxxxxxxxxx>
>> Signed-off-by: Amit Daniel Kachhap <amit.daniel@xxxxxxxxxxx>
>> ---
>> .../devicetree/bindings/thermal/exynos-thermal.txt | 28 ++++++++++++-
>> drivers/thermal/samsung/exynos_tmu.c | 43 +++++++++++++++++--
>> drivers/thermal/samsung/exynos_tmu.h | 6 +++
>> drivers/thermal/samsung/exynos_tmu_data.h | 2 +
>> 4 files changed, 72 insertions(+), 7 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/thermal/exynos-thermal.txt b/Documentation/devicetree/bindings/thermal/exynos-thermal.txt
>> index 535fd0e..970eeba 100644
>> --- a/Documentation/devicetree/bindings/thermal/exynos-thermal.txt
>> +++ b/Documentation/devicetree/bindings/thermal/exynos-thermal.txt
>> @@ -6,13 +6,16 @@
>> "samsung,exynos4412-tmu"
>> "samsung,exynos4210-tmu"
>> "samsung,exynos5250-tmu"
>> + "samsung,exynos5440-tmu"
>> - interrupt-parent : The phandle for the interrupt controller
>> -- reg : Address range of the thermal registers
>> +- reg : Address range of the thermal registers. For exynos5440-tmu which has 3
>> + instances of TMU, 2 set of register has to supplied. First set belongs
>> + to each instance of TMU and second set belongs to common TMU registers.
>> - interrupts : Should contain interrupt for thermal system
>> - clocks : The main clock for TMU device
>> - clock-names : Thermal system clock name
>>
>> -Example:
>> +Example 1):
>>
>> tmu@100C0000 {
>> compatible = "samsung,exynos4412-tmu";
>> @@ -23,3 +26,24 @@ Example:
>> clock-names = "tmu_apbif";
>> status = "disabled";
>> };
>> +
>> +Example 2):
>> +
>> + tmuctrl_0: tmuctrl@160118 {
>> + compatible = "samsung,exynos5440-tmu";
>> + reg = <0x160118 0x230>, <0x160368 0x10>;
>> + interrupts = <0 58 0>;
>> + clocks = <&clock 21>;
>> + clock-names = "tmu_apbif";
>> + };
>> +
>> +Note: For multi-instance tmu each instance should have an alias correctly
>> +numbered in "aliases" node.
>> +
>> +Example:
>> +
>> +aliases {
>> + tmuctrl0 = &tmuctrl_0;
>> + tmuctrl1 = &tmuctrl_1;
>> + tmuctrl2 = &tmuctrl_2;
>> +};
>> diff --git a/drivers/thermal/samsung/exynos_tmu.c b/drivers/thermal/samsung/exynos_tmu.c
>> index 7f7b1cf..7ca9c4d 100644
>> --- a/drivers/thermal/samsung/exynos_tmu.c
>> +++ b/drivers/thermal/samsung/exynos_tmu.c
>> @@ -185,9 +185,11 @@ static int exynos_tmu_initialize(struct platform_device *pdev)
>> reg->threshold_th0 + i * sizeof(reg->threshold_th0));
>>
>> writel(reg->inten_rise_mask, data->base + reg->tmu_intclear);
>> - } else if (data->soc == SOC_ARCH_EXYNOS) {
>> + } else if (data->soc == SOC_ARCH_EXYNOS ||
>> + data->soc == SOC_ARCH_EXYNOS5440) {
>> /* Write temperature code for rising and falling threshold */
>> - for (i = 0; i < trigger_levs; i++) {
>> + for (i = 0;
>> + i < trigger_levs && i < EXYNOS_MAX_TRIGGER_PER_REG; i++) {
>> threshold_code = temp_to_code(data,
>> pdata->trigger_levels[i]);
>> if (threshold_code < 0) {
>> @@ -218,7 +220,30 @@ static int exynos_tmu_initialize(struct platform_device *pdev)
>> writel((reg->inten_rise_mask << reg->inten_rise_shift) |
>> (reg->inten_fall_mask << reg->inten_fall_shift),
>> data->base + reg->tmu_intclear);
>> +
>> + /* if 5th threshold limit is also present, use TH2 register */
>> + i = EXYNOS_MAX_TRIGGER_PER_REG;
>> + if (pdata->trigger_levels[i]) {
>> + threshold_code = temp_to_code(data,
>> + pdata->trigger_levels[i]);
>> + if (threshold_code < 0) {
>> + ret = threshold_code;
>> + goto out;
>> + }
>> + rising_threshold =
>> + threshold_code << reg->threshold_th3_l0_shift;
>> + writel(rising_threshold,
>> + data->base + reg->threshold_th2);
>> + if (pdata->trigger_type[i] == HW_TRIP) {
>> + con = readl(data->base + reg->tmu_ctrl);
>> + con |= (1 << reg->therm_trip_en_shift);
>> + writel(con, data->base + reg->tmu_ctrl);
>> + }
>> + }
>> }
>> + /*Clear the PMIN in the common TMU register*/
>> + if (reg->tmu_pmin && !data->id)
>> + writel(0, data->base_common + reg->tmu_pmin);
>> out:
>> clk_disable(data->clk);
>> mutex_unlock(&data->lock);
>> @@ -345,7 +370,14 @@ static void exynos_tmu_work(struct work_struct *work)
>> struct exynos_tmu_data, irq_work);
>> struct exynos_tmu_platform_data *pdata = data->pdata;
>> const struct exynos_tmu_registers *reg = pdata->registers;
>> - unsigned int val_irq;
>> + unsigned int val_irq, val_type;
>> +
>> + /* Find which sensor generated this interrupt */
>> + if (reg->tmu_irqstatus) {
>> + val_type = readl(data->base_common + reg->tmu_irqstatus);
>> + if (!((val_type >> data->id) & 0x1))
>> + goto out;
>
>
> I have a question about your implementation for supporting EXYNOS5440.
> I don't know exactly how EXYNO5440's tmu is working, but just guess it would be
> similar with other EXYNOS series's without number of thermal sensors. (exclusive
> register map and threshold level). Due to the multiple number of thermal sensor
> in EXYNOS5440, it have multiple thermal zone devices and that's why it just
> leave interrupt pin in pending if interrupt is not its, right?
Yes in 5440 the interrupt line is shared so pending bit is left uncleared.
>
> So, my curious is, why we make all platform devices for each of thermal zone
> devices? Why don't you just handle all thermal zone devices with one platform
> device?
Your doubt is genuine. Let me justify my design decision.
Initially I also thought of making a single platform device but since
there are 3 different TMU controllers and register maps for 4 more so
I followed this design as the driver looks clean and can be scalable
easily. Also I agree that some resources like IRQ line is shared but
it is due to h/w limitation.
Also it is easy to cleanly control each TMU instance with the device
tree data similar to I2C/SPI/MMC instance based device driver. Say I
do not want to use 2nd sensor then just pass device tree data for 1st
and 3rd sensor.
>
> Yes, It's probably right to make multiple devices node to support them, because
> it has different physical hardware(sensors). But we have one TMU , don't we?
> (Maybe my assumption is wrong, I assume that it has one TMU because it looks
> like it has only one irq line.). If I'm right, I think it is better to manage
> all thermal zone devices with one platform device. Then, we don't need to leave
> irq handler with leaving it pendded like above and also we may not need other
> your patches like adding base_common iomem variable.
Agreed that base_common variables is extra and present to handle the
common part. I will further analyse your suggestion.
Thanks,
Amit Daniel
>
> I'd like to listen your opinion about this.
>
> Thanks,
> Jonghwa
>
>> + }
>>
>> exynos_report_trigger(data->reg_conf);
>> mutex_lock(&data->lock);
>> @@ -358,7 +390,7 @@ static void exynos_tmu_work(struct work_struct *work)
>>
>> clk_disable(data->clk);
>> mutex_unlock(&data->lock);
>> -
>> +out:
>> enable_irq(data->irq);
>> }
>>
>> @@ -520,7 +552,8 @@ static int exynos_tmu_probe(struct platform_device *pdev)
>> return ret;
>>
>> if (pdata->type == SOC_ARCH_EXYNOS ||
>> - pdata->type == SOC_ARCH_EXYNOS4210)
>> + pdata->type == SOC_ARCH_EXYNOS4210 ||
>> + pdata->type == SOC_ARCH_EXYNOS5440)
>> data->soc = pdata->type;
>> else {
>> ret = -EINVAL;
>> diff --git a/drivers/thermal/samsung/exynos_tmu.h b/drivers/thermal/samsung/exynos_tmu.h
>> index 65443d7..9151a30 100644
>> --- a/drivers/thermal/samsung/exynos_tmu.h
>> +++ b/drivers/thermal/samsung/exynos_tmu.h
>> @@ -44,6 +44,7 @@ enum trigger_type {
>> enum soc_type {
>> SOC_ARCH_EXYNOS4210 = 1,
>> SOC_ARCH_EXYNOS,
>> + SOC_ARCH_EXYNOS5440,
>> };
>>
>> /**
>> @@ -132,6 +133,8 @@ enum soc_type {
>> * @emul_temp_shift: shift bits of emulation temperature.
>> * @emul_time_shift: shift bits of emulation time.
>> * @emul_time_mask: mask bits of emulation time.
>> + * @tmu_irqstatus: register to find which TMU generated interrupts.
>> + * @tmu_pmin: register to get/set the Pmin value.
>> */
>> struct exynos_tmu_registers {
>> u32 triminfo_data;
>> @@ -199,6 +202,9 @@ struct exynos_tmu_registers {
>> u32 emul_temp_shift;
>> u32 emul_time_shift;
>> u32 emul_time_mask;
>> +
>> + u32 tmu_irqstatus;
>> + u32 tmu_pmin;
>> };
>>
>> /**
>> diff --git a/drivers/thermal/samsung/exynos_tmu_data.h b/drivers/thermal/samsung/exynos_tmu_data.h
>> index 0e2244f..4acf070 100644
>> --- a/drivers/thermal/samsung/exynos_tmu_data.h
>> +++ b/drivers/thermal/samsung/exynos_tmu_data.h
>> @@ -91,6 +91,8 @@
>> #define EXYNOS_EMUL_DATA_MASK 0xFF
>> #define EXYNOS_EMUL_ENABLE 0x1
>>
>> +#define EXYNOS_MAX_TRIGGER_PER_REG 4
>> +
>> #if defined(CONFIG_CPU_EXYNOS4210)
>> extern struct exynos_tmu_platform_data const exynos4210_default_tmu_data;
>> #define EXYNOS4210_TMU_DRV_DATA (&exynos4210_default_tmu_data)
>
>
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