On Thu, Feb 8, 2018 at 4:27 PM, Amelie Delaunay <amelie.delaunay@xxxxxx> wrote: > ST Multi-Function eXpander (MFX) can be used as GPIO expander. > It has 16 fast GPIOs and can have 8 extra alternate GPIOs > when other MFX features are not enabled. > +config GPIO_ST_MFX > + bool "ST-MFX GPIOs" > + depends on MFD_ST_MFX > + depends on OF_GPIO > + select GPIOLIB_IRQCHIP > + help > + GPIO driver for STMicroelectronics Multi-Function eXpander. > + > + This provides GPIO interface supporting inputs and outputs. > +/* > + * STMicroelectronics Multi-Function eXpander (ST-MFX) - GPIO expander driver. > + * > + * Copyright (C) 2017, STMicroelectronics - All Rights Reserved > + * Author(s): Amelie Delaunay <amelie.delaunay@xxxxxx> for STMicroelectronics. > + * License terms: GPL V2.0. > + * > + * st-mfx-gpio 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. > + * > + * st-mfx-gpio 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. > + * > + * You should have received a copy of the GNU General Public License along with > + * st-mfx-gpio. If not, see <http://www.gnu.org/licenses/>. Use SPDX instead. > + */ > +#include <linux/of_gpio.h> > +/* MFX has a maximum of 24 gpios, with 8 gpios per bank, so 3 banks maximum */ > +#define NR_MAX_GPIOS 24 > +#define NR_GPIOS_PER_BANK 8 > +#define NR_MAX_BANKS (NR_MAX_GPIOS / NR_GPIOS_PER_BANK) > +#define get_bank(offset) ((u8)((offset) / NR_GPIOS_PER_BANK)) > +#define get_mask(offset) ((u8)BIT((offset) % NR_GPIOS_PER_BANK)) I would rather keep it consistent, i.e. get_bank() [as is] get_mask -> get_shift() [w/o BIT() macro] > +enum { REG_IRQ_SRC, REG_IRQ_EVT, REG_IRQ_TYPE, NR_CACHE_IRQ_REGS }; Please, do one item per line. > +/* > + * This is MFX-specific flags, overloading Linux-specific of_gpio_flags, > + * needed in of_xlate callback. > + * on MFX: - if GPIO is output: Split to two lines. > + * * (0) means PUSH_PULL > + * * OF_GPIO_SINGLE_ENDED (=2) means OPEN-DRAIN > + * - if GPIO is input: > + * * (0) means NO_PULL > + * * OF_MFX_GPI_PUSH_PULL (=2) means PUSH_PULL > + * > + * * OF_MFX_GPIO_PULL_UP programs pull up resistor on the GPIO, > + * whatever its direction, without this flag, depending on > + * GPIO type and direction, it programs either no pull or > + * pull down resistor. > + */ > +enum of_mfx_gpio_flags { > + OF_MFX_GPI_PUSH_PULL = 0x2, > + OF_MFX_GPIO_PULL_UP = 0x4, These have misleading prefix. OF_ is reserved for general OF stuff. > +}; > + > +struct mfx_gpio { > + struct gpio_chip gc; > + struct mfx *mfx; > + struct device *dev; Don't you have it in gc above as a parent device? > + struct mutex irq_lock; /* IRQ bus lock */ > + u32 flags[NR_MAX_GPIOS]; > + /* Caches of interrupt control registers for bus_lock */ > + u8 regs[NR_CACHE_IRQ_REGS][NR_MAX_BANKS]; > + u8 oldregs[NR_CACHE_IRQ_REGS][NR_MAX_BANKS]; > +}; > +static int mfx_gpio_direction_input(struct gpio_chip *gc, > + unsigned int offset) > +{ > + struct mfx_gpio *mfx_gpio = gpiochip_get_data(gc); > + struct mfx *mfx = mfx_gpio->mfx; > + u8 reg_type = MFX_REG_GPIO_TYPE + get_bank(offset); > + u8 reg_pupd = MFX_REG_GPIO_PUPD + get_bank(offset); > + u8 reg_dir = MFX_REG_GPIO_DIR + get_bank(offset); > + u8 mask = get_mask(offset); > + int ret; > + > + /* > + * In case of input direction, there is actually no way to apply some > + * configuration in hardware, as it can be done with > + * .set_config in case of output direction. That's why we apply > + * here the MFX specific-flags. > + */ > + if (mfx_gpio->flags[offset] & OF_MFX_GPI_PUSH_PULL) > + ret = mfx_set_bits(mfx, reg_type, mask, mask); > + else > + ret = mfx_set_bits(mfx, reg_type, mask, 0); > + Redundant empty line. > + if (ret) > + return ret; > + > + if (mfx_gpio->flags[offset] & OF_MFX_GPIO_PULL_UP) > + ret = mfx_set_bits(mfx, reg_pupd, mask, mask); > + else > + ret = mfx_set_bits(mfx, reg_pupd, mask, 0); > + Ditto. > + if (ret) > + return ret; > + > + return mfx_set_bits(mfx, reg_dir, mask, 0); > +} > +static void mfx_gpio_dbg_show(struct seq_file *s, struct gpio_chip *gc) > +{ > + struct mfx_gpio *mfx_gpio = gpiochip_get_data(gc); > + struct mfx *mfx = mfx_gpio->mfx; > + u16 i; > + > + for (i = 0; i < gc->ngpio; i++) { > + int gpio = i + gc->base; > + const char *label = gpiochip_is_requested(gc, i); > + int dir = mfx_gpio_get_direction(gc, i); > + int val = mfx_gpio_get(gc, i); > + u8 mask = get_mask(i); > + u8 reg; > + int type, pupd; > + int irqsrc, irqevt, irqtype, irqpending; > + if (!label) > + label = "Unrequested"; I would rather put label = gpiochip_...(); immediately before this condition for better readability. > + > + seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label); > + > + reg = MFX_REG_IRQ_GPI_PENDING + get_bank(i); > + irqpending = mfx_reg_read(mfx, reg); > + if (irqpending < 0) > + return; > + irqpending = !!(irqpending & mask); > + > + if (!dir) { Why not to use if (dir) { ? > + seq_printf(s, "out %s ", val ? "high" : "low"); > + if (type) > + seq_puts(s, "open drain "); > + else > + seq_puts(s, "push pull "); > + if (pupd && type) > + seq_puts(s, "with internal pull-up "); > + else > + seq_puts(s, "without internal pull-up "); > + } else { > + seq_printf(s, "in %s ", val ? "high" : "low"); > + if (type) > + seq_printf(s, "with internal pull-%s ", > + pupd ? "up" : "down"); > + else > + seq_printf(s, "%s ", > + pupd ? "floating" : "analog"); > + } > + > + if (irqsrc) { > + seq_printf(s, "IRQ generated on %s %s", > + !irqevt ? > + (!irqtype ? "Low level" : "High level") : > + (!irqtype ? "Falling edge" : "Rising edge"), > + irqpending ? "(pending)" : ""); Why do you use negative conditions? Use positive ones. > + } > + > + seq_puts(s, "\n"); > + } > +} > +static void mfx_gpio_irq_toggle_trigger(struct gpio_chip *gc, int offset) > +{ > + struct mfx_gpio *mfx_gpio = gpiochip_get_data(gc); > + struct mfx *mfx = mfx_gpio->mfx; > + u8 bank = get_bank(offset); > + u8 mask = get_mask(offset); > + int val = mfx_gpio_get(gc, offset); > + > + if (val < 0) { > + dev_err(mfx_gpio->dev, "can't get value of gpio%d: ret=%d\n", > + offset, val); Is it somehow useful on err level? > + return; > + } > +} > +static int mfx_gpio_irq_set_type(struct irq_data *d, unsigned int type) > +{ > + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); > + struct mfx_gpio *mfx_gpio = gpiochip_get_data(gc); > + int bank = get_bank(d->hwirq); > + int mask = get_mask(d->hwirq); > + > + if ((type & IRQ_TYPE_LEVEL_LOW) || (type & IRQ_TYPE_LEVEL_HIGH)) IRQ_TYPE_LEVEL_MASK? > + mfx_gpio->regs[REG_IRQ_EVT][bank] &= ~mask; > + else > + mfx_gpio->regs[REG_IRQ_EVT][bank] |= mask; > + > + if ((type & IRQ_TYPE_EDGE_RISING) || (type & IRQ_TYPE_LEVEL_HIGH)) IRQ_TYPE_EDGE_BOTH ? > + mfx_gpio->regs[REG_IRQ_TYPE][bank] |= mask; > + else > + mfx_gpio->regs[REG_IRQ_TYPE][bank] &= ~mask; > + > +} > +static void mfx_gpio_irq_lock(struct irq_data *d) Missed annotation that this acquires a lock. > +static void mfx_gpio_irq_sync_unlock(struct irq_data *d) Ditto for releasing lock. > +static irqreturn_t mfx_gpio_irq(int irq, void *dev) > +{ > + struct mfx_gpio *mfx_gpio = dev; > + struct mfx *mfx = mfx_gpio->mfx; > + int num_banks = mfx->num_gpio / 8; > + u8 status[num_banks]; > + int ret; > + u8 bank; Swap lines. > + > + ret = mfx_block_read(mfx, MFX_REG_IRQ_GPI_PENDING, ARRAY_SIZE(status), > + status); > + if (ret < 0) { > + dev_err(mfx_gpio->dev, "can't get IRQ_GPI_PENDING: %d\n", ret); In IRQ context on err level? Hmm... > + return IRQ_NONE; > + } > + > + for (bank = 0; bank < ARRAY_SIZE(status); bank++) { > + u8 stat = status[bank]; > + > + if (!stat) > + continue; > + > + while (stat) { > + int bit = __ffs(stat); for_each_set_bit() ? > + int offset = bank * NR_GPIOS_PER_BANK + bit; > + int gpio_irq = irq_find_mapping(mfx_gpio->gc.irq.domain, > + offset); > + int irq_trigger = irq_get_trigger_type(gpio_irq); > + > + handle_nested_irq(gpio_irq); > + stat &= ~(BIT(bit)); > + > + if (irq_trigger & IRQ_TYPE_EDGE_BOTH) > + mfx_gpio_irq_toggle_trigger(&mfx_gpio->gc, > + offset); > + } > + > + mfx_reg_write(mfx, MFX_REG_IRQ_GPI_ACK + bank, status[bank]); > + } > + > + return IRQ_HANDLED; > +} -- With Best Regards, Andy Shevchenko -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 3/6] gpio: Add GPIO support for the ST Multi-Function eXpander
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- Subject: Re: [PATCH 3/6] gpio: Add GPIO support for the ST Multi-Function eXpander
- From: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
- Date: Wed, 14 Feb 2018 17:30:22 +0200
- In-reply-to: <1518100057-23234-4-git-send-email-amelie.delaunay@st.com>
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