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Message-ID: <51ADE3B6.2050709@ti.com>
Date: Tue, 4 Jun 2013 08:55:18 -0400
From: Eduardo Valentin <eduardo.valentin@...com>
To: amit daniel kachhap <amit.daniel@...sung.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>,
Eduardo Valentin <eduardo.valentin@...com>
Subject: Re: [PATCH V4 22/30] thermal: exynos: Add support for exynos5440
TMU sensor.
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?
> 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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