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Date: Tue, 27 May 2014 16:35:41 +0100
From: Lee Jones <lee.jones@...aro.org>
To: "Zhu, Lejun" <lejun.zhu@...ux.intel.com>
Cc: broonie@...nel.org, sameo@...ux.intel.com,
linux-kernel@...r.kernel.org, jacob.jun.pan@...ux.intel.com,
bin.yang@...el.com
Subject: Re: [PATCH v3 1/4] mfd: intel_soc_pmic: Core driver
> This patch provides the common code for the intel_soc_pmic MFD driver, such as read/write register and set up IRQ.
>
> v2:
> - Use regmap instead of our own callbacks for read/write.
> - Add one missing EXPORT_SYMBOL.
> - Remove some duplicate code and put them into pmic_regmap_load_from_hw.
> v3:
> - Use regmap-irq. Remove our own pmic_regmap_* and IRQ handling code.
> - Remove intel_soc_pmic_dev() because gpio driver no longer uses it.
> - Remove intel_soc_pmic_set_pdata() because currently it's not used.
> - Use EXPORT_SYMBOL_GPL for exposed APIs.
>
> Signed-off-by: Yang, Bin <bin.yang@...el.com>
> Signed-off-by: Zhu, Lejun <lejun.zhu@...ux.intel.com>
> ---
> drivers/mfd/intel_soc_pmic_core.c | 212 +++++++++++++++++++++++++++++++++++++
> drivers/mfd/intel_soc_pmic_core.h | 44 ++++++++
> include/linux/mfd/intel_soc_pmic.h | 27 +++++
> 3 files changed, 283 insertions(+)
> create mode 100644 drivers/mfd/intel_soc_pmic_core.c
> create mode 100644 drivers/mfd/intel_soc_pmic_core.h
> create mode 100644 include/linux/mfd/intel_soc_pmic.h
>
> diff --git a/drivers/mfd/intel_soc_pmic_core.c b/drivers/mfd/intel_soc_pmic_core.c
> new file mode 100644
> index 0000000..4f95a4a
> --- /dev/null
> +++ b/drivers/mfd/intel_soc_pmic_core.c
> @@ -0,0 +1,212 @@
> +/*
> + * intel_soc_pmic_core.c - Intel SoC PMIC Core Functions
> + *
> + * Copyright (C) 2013, 2014 Intel Corporation. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License version
> + * 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * Author: Yang, Bin <bin.yang@...el.com>
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/delay.h>
> +#include <linux/mutex.h>
> +#include <linux/mfd/core.h>
> +#include <linux/err.h>
> +#include <linux/irq.h>
> +#include <linux/interrupt.h>
> +#include <linux/workqueue.h>
> +#include <linux/acpi.h>
> +#include <linux/version.h>
> +#include <linux/gpio.h>
> +#include <linux/regmap.h>
> +#include <linux/mfd/intel_soc_pmic.h>
> +#include "intel_soc_pmic_core.h"
> +
> +static DEFINE_MUTEX(pmic_lock); /* protect pmic */
> +static struct intel_soc_pmic *pmic;
> +
> +/*
> + * Read from a PMIC register
> + */
> +int intel_soc_pmic_readb(int reg)
> +{
> + int ret;
> + unsigned int val;
> +
> + mutex_lock(&pmic_lock);
> +
> + if (!pmic) {
> + ret = -EIO;
> + } else {
> + ret = regmap_read(pmic->regmap, reg, &val);
> + if (!ret)
> + ret = val;
> + }
> +
> + mutex_unlock(&pmic_lock);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(intel_soc_pmic_readb);
> +
> +/*
> + * Write to a PMIC register
> + */
> +int intel_soc_pmic_writeb(int reg, u8 val)
> +{
> + int ret;
> +
> + mutex_lock(&pmic_lock);
> +
> + if (!pmic)
> + ret = -EIO;
> + else
> + ret = regmap_write(pmic->regmap, reg, val);
> +
> + mutex_unlock(&pmic_lock);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(intel_soc_pmic_writeb);
> +
> +/*
> + * Set 1 bit in a PMIC register
> + */
> +int intel_soc_pmic_setb(int reg, u8 mask)
> +{
> + int ret;
> +
> + mutex_lock(&pmic_lock);
> +
> + if (!pmic)
> + ret = -EIO;
> + else
> + ret = regmap_update_bits(pmic->regmap, reg, mask, mask);
> +
> + mutex_unlock(&pmic_lock);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(intel_soc_pmic_setb);
> +
> +/*
> + * Clear 1 bit in a PMIC register
> + */
> +int intel_soc_pmic_clearb(int reg, u8 mask)
> +{
> + int ret;
> +
> + mutex_lock(&pmic_lock);
> +
> + if (!pmic)
> + ret = -EIO;
> + else
> + ret = regmap_update_bits(pmic->regmap, reg, mask, 0);
> +
> + mutex_unlock(&pmic_lock);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(intel_soc_pmic_clearb);
> +
> +/*
> +* Set and clear multiple bits of a PMIC register
> +*/
> +int intel_soc_pmic_update(int reg, u8 val, u8 mask)
> +{
> + int ret;
> +
> + mutex_lock(&pmic_lock);
> +
> + if (!pmic)
> + ret = -EIO;
> + else
> + ret = regmap_update_bits(pmic->regmap, reg, mask, val);
> +
> + mutex_unlock(&pmic_lock);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(intel_soc_pmic_update);
I'm really not a fan of all these pointless agregation call-backs. I
see them as unesersary overhead. Just use the regmap API directly.
> +int intel_pmic_add(struct intel_soc_pmic *chip)
> +{
> + int ret;
> + struct intel_soc_pmic_config *cfg = chip->config;
> +
> + mutex_lock(&pmic_lock);
> +
> + if (pmic != NULL) {
if (pmic)
> + mutex_unlock(&pmic_lock);
> + return -EBUSY;
> + }
> +
> + pmic = chip;
> +
> + mutex_unlock(&pmic_lock);
> +
> + if (cfg->init) {
> + ret = cfg->init();
All this does is invokes a dev_info() message. Until this does
something useful, please remove it.
> + if (ret != 0)
if (ret)
Same with all "!= 0" checks.
> + goto err;
> + }
> +
> + ret = regmap_add_irq_chip(chip->regmap, chip->irq,
> + cfg->irq_flags | IRQF_ONESHOT,
> + 0, cfg->irq_chip,
> + &chip->irq_chip_data);
> + if (ret != 0)
> + goto err;
> +
> + ret = enable_irq_wake(chip->irq);
> + if (ret != 0)
> + dev_warn(chip->dev, "Can't enable IRQ as wake source: %d\n",
> + ret);
> +
> + ret = mfd_add_devices(chip->dev, -1, cfg->cell_dev,
> + cfg->n_cell_devs, NULL, 0,
> + regmap_irq_get_domain(chip->irq_chip_data));
> +
Remove this line.
> + if (ret)
> + goto err_del_irq_chip;
> +
> + return 0;
> +
> +err_del_irq_chip:
> + regmap_del_irq_chip(chip->irq, chip->irq_chip_data);
> +err:
> + mutex_lock(&pmic_lock);
> + if (pmic == chip)
> + pmic = NULL;
> + mutex_unlock(&pmic_lock);
I don't think this locking is required here, and won't pmic == chip
always be true?
> + return ret;
> +}
> +
> +int intel_pmic_remove(struct intel_soc_pmic *chip)
> +{
> + mutex_lock(&pmic_lock);
> +
> + if (pmic != chip) {
> + mutex_unlock(&pmic_lock);
> + return -ENODEV;
> + }
> +
> + pmic = NULL;
> +
> + mutex_unlock(&pmic_lock);
I'm not sure the locks are required here either.
> + regmap_del_irq_chip(chip->irq, chip->irq_chip_data);
> +
> + mfd_remove_devices(chip->dev);
> +
> + return 0;
> +}
[...]
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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