Re: [PATCH] gpio: Add support for Intel SoC PMIC (Crystal Cove)

From: Zhu, Lejun
Date: Sun May 18 2014 - 20:27:18 EST

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In reply to: Linus Walleij: "Re: [PATCH] gpio: Add support for Intel SoC PMIC (Crystal Cove)"
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On 5/17/2014 1:33 AM, Linus Walleij wrote:
> On Wed, May 14, 2014 at 5:44 PM, Zhu, Lejun <lejun.zhu@xxxxxxxxxxxxxxx> wrote:
>
>> Devices based on Intel SoC products such as Baytrail have a Power
>> Management IC. In the PMIC there are subsystems for voltage regulation,
>> A/D conversion, GPIO and PWMs. The PMIC in Baytrail-T platform is called
>> Crystal Cove.
>>
>> This patch adds support for the GPIO function in Crystal Cove.
>>
>> Signed-off-by: Yang, Bin <bin.yang@xxxxxxxxx>
>> Signed-off-by: Zhu, Lejun <lejun.zhu@xxxxxxxxxxxxxxx>
>
> (...)
>
>> +config GPIO_INTEL_SOC_PMIC
>> + bool "GPIO on Intel SoC PMIC"
>> + depends on INTEL_SOC_PMIC
>
> select GPIOLIB_IRQCHIP
>
> and use the infrastructure from commit
> 1425052097b53de841e064dc190a9009480c208c
> "gpio: add IRQ chip helpers in gpiolib"
>
> Some fixes for sleeping chips have been merged and are available
> on the "devel" branch in the GPIO tree, so you may need to base
> your development on that.
>
> Adding some kerneldoc to the below struct will maybe make you
> realize whether you actually need it or not.
>
>> +struct crystalcove_gpio {
>> + struct mutex buslock; /* irq_bus_lock */
>> + struct gpio_chip chip;
>> + int irq;
>> + int irq_base;
>
> You should not have hardcoded IRQ bases around. Use an irqdomain
> to map IRQs, and even better: use the one provided in
> chip->irqdomain by GPIOLIB_IRQCHIP. (It's a requirement.)
>
>> + int update;
>> + int trigger_type;
>> + int irq_mask;
>
> Should this be a bool since you just set it to 0 or 1?
>
>> +};
>> +static struct crystalcove_gpio gpio_info;
>> +
>> +static void __crystalcove_irq_mask(int gpio, int mask)
>
> I don't really like __doubleunderscore specifiers, can you use a
> unique name or something instead.
>
>> +{
>> + u8 mirqs0 = gpio < 8 ? MGPIO0IRQS0 : MGPIO1IRQS0;
>> + int offset = gpio < 8 ? gpio : gpio - 8;
>
> Meh.
> unsigned int offset = gpio%8;
>
>> +
>> + if (mask)
>> + intel_soc_pmic_setb(mirqs0, 1 << offset);
>
> Use
> #include <linux/bitops.h>
>
> intel_soc_pmic_setb(mirqs0, BIT(offset));
>
> I really like the BIT() macros.
>
>> + else
>> + intel_soc_pmic_clearb(mirqs0, 1 << offset);
>
> Dito.
>
>> +static void __crystalcove_irq_type(int gpio, int type)
>> +{
>> + u8 ctli = gpio < 8 ? GPIO0P0CTLI + gpio : GPIO1P0CTLI + (gpio - 8);
>
> Do it like the first time instead, this is hard to read.
>
>> + type &= IRQ_TYPE_EDGE_BOTH;
>> + intel_soc_pmic_clearb(ctli, CTLI_INTCNT_BE);
>> +
>> + if (type == IRQ_TYPE_EDGE_BOTH)
>> + intel_soc_pmic_setb(ctli, CTLI_INTCNT_BE);
>> + else if (type == IRQ_TYPE_EDGE_RISING)
>> + intel_soc_pmic_setb(ctli, CTLI_INTCNT_PE);
>> + else if (type & IRQ_TYPE_EDGE_FALLING)
>> + intel_soc_pmic_setb(ctli, CTLI_INTCNT_NE);
>> +}
>> +
>> +static int crystalcove_gpio_direction_input(struct gpio_chip *chip,
>> + unsigned gpio)
>> +{
>> + u8 ctlo = gpio < 8 ? GPIO0P0CTLO + gpio : GPIO1P0CTLO + (gpio - 8);
>
> Dito.
>
>> +
>> + intel_soc_pmic_writeb(ctlo, CTLO_INPUT_DEF);
>> + return 0;
>> +}
>> +
>> +static int crystalcove_gpio_direction_output(struct gpio_chip *chip,
>> + unsigned gpio, int value)
>> +{
>> + u8 ctlo = gpio < 8 ? GPIO0P0CTLO + gpio : GPIO1P0CTLO + (gpio - 8);
>
> Dito. (etc for all)
>
>> +
>> + intel_soc_pmic_writeb(ctlo, CTLO_OUTPUT_DEF | value);
>> + return 0;
>> +}
>> +
>> +static int crystalcove_gpio_get(struct gpio_chip *chip, unsigned gpio)
>> +{
>> + u8 ctli = gpio < 8 ? GPIO0P0CTLI + gpio : GPIO1P0CTLI + (gpio - 8);
>> +
>> + return intel_soc_pmic_readb(ctli) & 0x1;
>> +}
>> +
>> +static void crystalcove_gpio_set(struct gpio_chip *chip,
>> + unsigned gpio, int value)
>> +{
>> + u8 ctlo = gpio < 8 ? GPIO0P0CTLO + gpio : GPIO1P0CTLO + (gpio - 8);
>> +
>> + if (value)
>> + intel_soc_pmic_setb(ctlo, 1);
>> + else
>> + intel_soc_pmic_clearb(ctlo, 1);
>> +}
>> +
>> +static int crystalcove_irq_type(struct irq_data *data, unsigned type)
>> +{
>> + struct crystalcove_gpio *cg = irq_data_get_irq_chip_data(data);
>> +
>> + cg->trigger_type = type;
>> + cg->update |= UPDATE_TYPE;
>> +
>> + return 0;
>> +}
>> +
>> +static int crystalcove_gpio_to_irq(struct gpio_chip *chip, unsigned gpio)
>> +{
>> + struct crystalcove_gpio *cg =
>> + container_of(chip, struct crystalcove_gpio, chip);
>> +
>> + return cg->irq_base + gpio;
>> +}
>
> Nope. Use the irqdomain in chip->irqdomain.
>
>> +static void crystalcove_bus_lock(struct irq_data *data)
>> +{
>> + struct crystalcove_gpio *cg = irq_data_get_irq_chip_data(data);
>
> This and all IRQ function callbacks needs to use a construct like
> this:
>
> struct gpio_chip *gc = irq_data_get_irq_chip_data(data);
> struct crystalcove_gpio *cg = container_of(gc, struct crystalcove_gpio, chip);
>
>> +
>> + mutex_lock(&cg->buslock);
>> +}
>> +
>> +static void crystalcove_bus_sync_unlock(struct irq_data *data)
>> +{
>
> The same here and for each irq function, as the irqchip helpers pass
> struct gpio_chip* as irq_chip_data.
>
>> + struct crystalcove_gpio *cg = irq_data_get_irq_chip_data(data);
>> + int gpio = data->irq - cg->irq_base;
>> +
>> + if (cg->update & UPDATE_TYPE)
>> + __crystalcove_irq_type(gpio, cg->trigger_type);
>> + if (cg->update & UPDATE_MASK)
>> + __crystalcove_irq_mask(gpio, cg->irq_mask);
>> + cg->update = 0;
>> +
>> + mutex_unlock(&cg->buslock);
>> +}
>> +
>> +static void crystalcove_irq_unmask(struct irq_data *data)
>> +{
>> + struct crystalcove_gpio *cg = irq_data_get_irq_chip_data(data);
>> +
>> + cg->irq_mask = 0;
>> + cg->update |= UPDATE_MASK;
>> +}
>> +
>> +static void crystalcove_irq_mask(struct irq_data *data)
>> +{
>> + struct crystalcove_gpio *cg = irq_data_get_irq_chip_data(data);
>> +
>> + cg->irq_mask = 1;
>> + cg->update |= UPDATE_MASK;
>> +}
>> +
>> +static struct irq_chip crystalcove_irqchip = {
>> + .name = "PMIC-GPIO",
>> + .irq_mask = crystalcove_irq_mask,
>> + .irq_unmask = crystalcove_irq_unmask,
>> + .irq_set_type = crystalcove_irq_type,
>> + .irq_bus_lock = crystalcove_bus_lock,
>> + .irq_bus_sync_unlock = crystalcove_bus_sync_unlock,
>> +};
>> +
>> +static irqreturn_t crystalcove_gpio_irq_handler(int irq, void *data)
>> +{
>> + struct crystalcove_gpio *cg = data;
>
> If you also use gpiochip_set_chained_irqchip() you need something like
> this here:
>
> struct gpio_chip *gc = data;
> then the container_of() construction.
>
>> + int pending;
>> + int gpio;
>> +
>> + pending = intel_soc_pmic_readb(GPIO0IRQ) & 0xff;
>> + pending |= (intel_soc_pmic_readb(GPIO1IRQ) & 0xff) << 8;
>> + intel_soc_pmic_writeb(GPIO0IRQ, pending & 0xff);
>> + intel_soc_pmic_writeb(GPIO1IRQ, (pending >> 8) & 0xff);
>> +
>> + local_irq_disable();
>> + for (gpio = 0; gpio < cg->chip.ngpio; gpio++)
>> + if (pending & (1 << gpio))
>> + generic_handle_irq(cg->irq_base + gpio);
>> + local_irq_enable();
>> +
>> + return IRQ_HANDLED;
>> +}
>> +
>> +static void crystalcove_gpio_dbg_show(struct seq_file *s,
>> + struct gpio_chip *chip)
>> +{
>> + struct crystalcove_gpio *cg =
>> + container_of(chip, struct crystalcove_gpio, chip);
>> + int gpio, offset;
>> + u8 ctlo, ctli, mirqs0, mirqsx, irq;
>> +
>> + for (gpio = 0; gpio < cg->chip.ngpio; gpio++) {
>> + offset = gpio < 8 ? gpio : gpio - 8;
>> + ctlo = intel_soc_pmic_readb(
>> + (gpio < 8 ? GPIO0P0CTLO : GPIO1P0CTLO) + offset);
>> + ctli = intel_soc_pmic_readb(
>> + (gpio < 8 ? GPIO0P0CTLI : GPIO1P0CTLI) + offset);
>> + mirqs0 = intel_soc_pmic_readb(
>> + gpio < 8 ? MGPIO0IRQS0 : MGPIO1IRQS0);
>> + mirqsx = intel_soc_pmic_readb(
>> + gpio < 8 ? MGPIO0IRQSX : MGPIO1IRQSX);
>> + irq = intel_soc_pmic_readb(
>> + gpio < 8 ? GPIO0IRQ : GPIO1IRQ);
>> + seq_printf(s, " gpio-%-2d %s %s %s %s ctlo=%2x,%s %s %s\n",
>> + gpio, ctlo & CTLO_DIR_OUT ? "out" : "in ",
>> + ctli & 0x1 ? "hi" : "lo",
>> + ctli & CTLI_INTCNT_NE ? "fall" : " ",
>> + ctli & CTLI_INTCNT_PE ? "rise" : " ",
>> + ctlo,
>> + mirqs0 & (1 << offset) ? "s0 mask " : "s0 unmask",
>> + mirqsx & (1 << offset) ? "sx mask " : "sx unmask",
>> + irq & (1 << offset) ? "pending" : " ");
>> + }
>> +}
>
> Looks helpful!
>
>> +static int crystalcove_gpio_probe(struct platform_device *pdev)
>> +{
>> + int irq = platform_get_irq(pdev, 0);
>> + struct crystalcove_gpio *cg = &gpio_info;
>> + int retval;
>> + int i;
>> + struct device *dev = intel_soc_pmic_dev();
>> +
>> + mutex_init(&cg->buslock);
>> + cg->chip.label = "intel_crystalcove";
>> + cg->chip.direction_input = crystalcove_gpio_direction_input;
>> + cg->chip.direction_output = crystalcove_gpio_direction_output;
>> + cg->chip.get = crystalcove_gpio_get;
>> + cg->chip.set = crystalcove_gpio_set;
>> + cg->chip.to_irq = crystalcove_gpio_to_irq;
>
> You don't define to_irq when using GPIOLIB_IRQCHIP.
>
>> + cg->chip.base = -1;
>> + cg->chip.ngpio = NUM_GPIO;
>> + cg->chip.can_sleep = 1;
>
> true. Set it to true. This is a bool.
>
>> + cg->chip.dev = dev;
>> + cg->chip.dbg_show = crystalcove_gpio_dbg_show;
>> +
>> + retval = gpiochip_add(&cg->chip);
>> + if (retval) {
>> + dev_warn(&pdev->dev, "add gpio chip error: %d\n", retval);
>> + goto out;
>> + }
>
> Skip from here:
>
>> + cg->irq_base = irq_alloc_descs(-1, 0, NUM_GPIO, 0);
>> + if (cg->irq_base < 0) {
>> + retval = cg->irq_base;
>> + cg->irq_base = 0;
>> + dev_warn(&pdev->dev, "irq_alloc_descs error: %d\n", retval);
>> + goto out_remove_gpio;
>> + }
>> +
>> + for (i = 0; i < NUM_GPIO; i++) {
>> + irq_set_chip_data(i + cg->irq_base, cg);
>> + irq_set_chip_and_handler_name(i + cg->irq_base,
>> + &crystalcove_irqchip,
>> + handle_simple_irq, "demux");
>> + }
>
> To here, replace with:
>
> gpiochip_irqchip_add(&cg->chip, &crystalcove_irqchip, cg->irq_base,
> handle_simple_irq, IRQ_TYPE_NONE);
>
>> + retval = request_threaded_irq(irq, NULL, crystalcove_gpio_irq_handler,
>> + IRQF_ONESHOT, "crystalcove_gpio", cg);
>> +
>> + if (retval) {
>> + dev_warn(&pdev->dev, "request irq failed: %d\n", retval);
>> + goto out_free_desc;
>> + }
>
> Maybe use
> gpiochip_set_chained_irqchip() here.
>
> Yours,
> Linus Walleij
>

Thank you. That's a long list and all of them indeed need to be fixed.
I'll work on them and submit v2 when ready.

Best Regards
Lejun

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Next message: Zhu, Lejun: "Re: [PATCH] gpio: Add support for Intel SoC PMIC (Crystal Cove)"
Previous message: Ming Lei: "Re: [PATCH] virtio_blk: fix race between start and stop queue"
In reply to: Linus Walleij: "Re: [PATCH] gpio: Add support for Intel SoC PMIC (Crystal Cove)"
Next in thread: Mathias Nyman: "Re: [PATCH] gpio: Add support for Intel SoC PMIC (Crystal Cove)"
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