Re: [PATCH v2 5/9] mfd: Add support for the MediaTek MT6358 PMIC

From: Nicolas Boichat
Date: Mon Mar 11 2019 - 04:22:20 EST

On Mon, Mar 11, 2019 at 11:48 AM Hsin-Hsiung Wang
<hsin-hsiung.wang@xxxxxxxxxxxx> wrote:
>
> This adds support for the MediaTek MT6358 PMIC. This is a
> multifunction device with the following sub modules:
>
> - Regulator
> - RTC
> - Codec
> - Interrupt
>
> It is interfaced to the host controller using SPI interface
> by a proprietary hardware called PMIC wrapper or pwrap.
> MT6358 MFD is a child device of the pwrap.
>
> Signed-off-by: Hsin-Hsiung Wang <hsin-hsiung.wang@xxxxxxxxxxxx>
> ---
> drivers/mfd/Makefile | 2 +-
> drivers/mfd/mt6358-irq.c | 236 +++++
> drivers/mfd/mt6397-core.c | 63 +-
> include/linux/mfd/mt6358/core.h | 158 +++
> include/linux/mfd/mt6358/registers.h | 1926 ++++++++++++++++++++++++++++++++++
> include/linux/mfd/mt6397/core.h | 3 +
> 6 files changed, 2386 insertions(+), 2 deletions(-)
> create mode 100644 drivers/mfd/mt6358-irq.c
> create mode 100644 include/linux/mfd/mt6358/core.h
> create mode 100644 include/linux/mfd/mt6358/registers.h
>
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index 088e249..50be021 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -230,7 +230,7 @@ obj-$(CONFIG_INTEL_SOC_PMIC) += intel-soc-pmic.o
> obj-$(CONFIG_INTEL_SOC_PMIC_BXTWC) += intel_soc_pmic_bxtwc.o
> obj-$(CONFIG_INTEL_SOC_PMIC_CHTWC) += intel_soc_pmic_chtwc.o
> obj-$(CONFIG_INTEL_SOC_PMIC_CHTDC_TI) += intel_soc_pmic_chtdc_ti.o
> -obj-$(CONFIG_MFD_MT6397) += mt6397-core.o mt6397-irq.o
> +obj-$(CONFIG_MFD_MT6397) += mt6397-core.o mt6397-irq.o mt6358-irq.o
>
> obj-$(CONFIG_MFD_ALTERA_A10SR) += altera-a10sr.o
> obj-$(CONFIG_MFD_SUN4I_GPADC) += sun4i-gpadc.o
> diff --git a/drivers/mfd/mt6358-irq.c b/drivers/mfd/mt6358-irq.c
> new file mode 100644
> index 0000000..2941d87
> --- /dev/null
> +++ b/drivers/mfd/mt6358-irq.c
> @@ -0,0 +1,236 @@
> +// SPDX-License-Identifier: GPL-2.0
> +//
> +// Copyright (c) 2019 MediaTek Inc.
> +
> +#include <linux/interrupt.h>
> +#include <linux/mfd/mt6358/core.h>
> +#include <linux/mfd/mt6358/registers.h>
> +#include <linux/mfd/mt6397/core.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/of_irq.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +
> +static struct irq_top_t mt6358_ints[] = {
> + MT6358_TOP_GEN(BUCK),
> + MT6358_TOP_GEN(LDO),
> + MT6358_TOP_GEN(PSC),
> + MT6358_TOP_GEN(SCK),
> + MT6358_TOP_GEN(BM),
> + MT6358_TOP_GEN(HK),
> + MT6358_TOP_GEN(AUD),
> + MT6358_TOP_GEN(MISC),
> +};
> +
> +static int parsing_hwirq_to_top_group(unsigned int hwirq)

I think mka@ already told you that, but I'd rename to something like
get_hwirq_top_group.

> +{
> + int top_group;
> +

Should we also add this? (I know that MT6358_TOP_GEN(BUCK).hwirq_base
== 0, but nothing really guarantees that.
if (mt6358_ints[0].hwirq_base < hwirq)
return -1;

> + for (top_group = 1; top_group < ARRAY_SIZE(mt6358_ints); top_group++) {
> + if (mt6358_ints[top_group].hwirq_base > hwirq) {
> + top_group--;
> + break;

More simply:
return top_group-1;

> + }
> + }
> + return top_group;

return -1 on error, and check for errors in the code below. If you
don't do that, you run the risk of accessing some array out of bounds.

> +}
> +
> +static void pmic_irq_enable(struct irq_data *data)
> +{
> + unsigned int hwirq = irqd_to_hwirq(data);
> + struct mt6397_chip *chip = irq_data_get_irq_chip_data(data);
> + struct pmic_irq_data *irqd = chip->irq_data;
> +
> + irqd->enable_hwirq[hwirq] = true;
> +}
> +
> +static void pmic_irq_disable(struct irq_data *data)
> +{
> + unsigned int hwirq = irqd_to_hwirq(data);
> + struct mt6397_chip *chip = irq_data_get_irq_chip_data(data);
> + struct pmic_irq_data *irqd = chip->irq_data;
> +
> + irqd->enable_hwirq[hwirq] = false;
> +}
> +
> +static void pmic_irq_lock(struct irq_data *data)
> +{
> + struct mt6397_chip *chip = irq_data_get_irq_chip_data(data);
> +
> + mutex_lock(&chip->irqlock);
> +}
> +
> +static void pmic_irq_sync_unlock(struct irq_data *data)
> +{
> + unsigned int i, top_gp, en_reg, int_regs, shift;
> + struct mt6397_chip *chip = irq_data_get_irq_chip_data(data);
> + struct pmic_irq_data *irqd = chip->irq_data;
> +
> + for (i = 0; i < irqd->num_pmic_irqs; i++) {
> + if (irqd->enable_hwirq[i] ==
> + irqd->cache_hwirq[i])

I think this fits in 80 chars.

> + continue;
> +
> + top_gp = parsing_hwirq_to_top_group(i);

This is quite inefficient: you keep going through mt6358_ints for all
i. Can you just figure out (and remember) which group we are currently
in in this loop?

outside the loop:
top_gp = 0;

here:
while ((top_gp+1) < ARRAY_SIZE(mt6358_ints) && i >=
mt6358_ints[top_gp+1].hwirq_base)
top_gp++;

> + int_regs = mt6358_ints[top_gp].num_int_bits / MT6358_REG_WIDTH;
> + en_reg = mt6358_ints[top_gp].en_reg +
> + mt6358_ints[top_gp].en_reg_shift * int_regs;
> + shift = (i - mt6358_ints[top_gp].hwirq_base) % MT6358_REG_WIDTH;
> + regmap_update_bits(chip->regmap, en_reg, BIT(shift),
> + irqd->enable_hwirq[i] << shift);
> + irqd->cache_hwirq[i] = irqd->enable_hwirq[i];
> + }
> + mutex_unlock(&chip->irqlock);
> +}
> +
> +static int pmic_irq_set_type(struct irq_data *data, unsigned int type)
> +{
> + return 0;
> +}

Why do you need to stub this function out? I think the core will
already check if the irq_chip supports this function or not. I think
you can just leave it as NULL in the struct below.

> +
> +static struct irq_chip mt6358_irq_chip = {
> + .name = "mt6358-irq",
> + .irq_enable = pmic_irq_enable,
> + .irq_disable = pmic_irq_disable,
> + .irq_bus_lock = pmic_irq_lock,
> + .irq_bus_sync_unlock = pmic_irq_sync_unlock,
> + .irq_set_type = pmic_irq_set_type,
> +};
> +
[snip]