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Date: Wed, 5 Jun 2013 08:50:34 +0530
From: amit daniel kachhap <amit.daniel@...sung.com>
To: Eduardo Valentin <eduardo.valentin@...com>
Cc: jonghwa3.lee@...sung.com, linux-pm@...r.kernel.org,
Zhang Rui <rui.zhang@...el.com>,
linux-samsung-soc@...r.kernel.org, linux-kernel@...r.kernel.org,
Kukjin Kim <kgene.kim@...sung.com>
Subject: Re: [PATCH V4 22/30] thermal: exynos: Add support for exynos5440 TMU sensor.
Hi Eduardo,
On Tue, Jun 4, 2013 at 6:25 PM, Eduardo Valentin
<eduardo.valentin@...com> wrote:
> On 04-06-2013 00:44, amit daniel kachhap wrote:
>> Hi Jonghwa,
>>
>> Sorry for the late reply as I was on leave.
>>
>> On Sat, May 18, 2013 at 10:53 AM, <jonghwa3.lee@...sung.com> wrote:
>>> On 2013년 05월 14일 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@...sung.com>
>>>> Signed-off-by: Amit Daniel Kachhap <amit.daniel@...sung.com>
>>>> ---
>>>> .../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@...C0000 {
>>>> compatible = "samsung,exynos4412-tmu";
>>>> @@ -23,3 +26,24 @@ Example:
>>>> clock-names = "tmu_apbif";
>>>> status = "disabled";
>>>> };
>>>> +
>>>> +Example 2):
>>>> +
>>>> + tmuctrl_0: tmuctrl@...118 {
>>>> + 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.
>>
>
> What is the relation TMU <--> temperature sensor? Is it one to one or
> one to many?
1 TMU --- > 1 temp sensor.(one to one)
Thanks,
Amit Daniel
>
>> 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)
>>>
>>>
>>
>>
>
>
> --
> You have got to be excited about what you are doing. (L. Lamport)
>
> Eduardo Valentin
>
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