[RFC 5/9] usb: gadget: function: mud: Add gpio support
Noralf Trønnes
noralf at tronnes.org
Sun Feb 16 17:21:13 UTC 2020
Add optional gpio functionality to the Multifunction USB Device.
Signed-off-by: Noralf Trønnes <noralf at tronnes.org>
---
drivers/usb/gadget/Kconfig | 14 +
drivers/usb/gadget/function/Makefile | 2 +
drivers/usb/gadget/function/f_mud_pins.c | 962 +++++++++++++++++++++++
3 files changed, 978 insertions(+)
create mode 100644 drivers/usb/gadget/function/f_mud_pins.c
diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index 9551876ffe08..d6285146ec76 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -219,6 +219,9 @@ config USB_F_TCM
config USB_F_MUD
tristate
+config USB_F_MUD_PINS
+ tristate
+
# this first set of drivers all depend on bulk-capable hardware.
config USB_CONFIGFS
@@ -493,6 +496,17 @@ menuconfig USB_CONFIGFS_F_MUD
help
Core support for the Multifunction USB Device.
+if USB_F_MUD
+
+config USB_CONFIGFS_F_MUD_PINS
+ bool "Multifunction USB Device GPIO"
+ depends on PINCTRL
+ select USB_F_MUD_PINS
+ help
+ GPIO support for the Multifunction USB Device.
+
+endif # USB_F_MUD
+
choice
tristate "USB Gadget precomposed configurations"
default USB_ETH
diff --git a/drivers/usb/gadget/function/Makefile b/drivers/usb/gadget/function/Makefile
index b6e31b511521..2e24227fcc12 100644
--- a/drivers/usb/gadget/function/Makefile
+++ b/drivers/usb/gadget/function/Makefile
@@ -52,3 +52,5 @@ usb_f_tcm-y := f_tcm.o
obj-$(CONFIG_USB_F_TCM) += usb_f_tcm.o
usb_f_mud-y := f_mud.o mud_regmap.o
obj-$(CONFIG_USB_F_MUD) += usb_f_mud.o
+usb_f_mud_pins-y := f_mud_pins.o
+obj-$(CONFIG_USB_F_MUD_PINS) += usb_f_mud_pins.o
diff --git a/drivers/usb/gadget/function/f_mud_pins.c b/drivers/usb/gadget/function/f_mud_pins.c
new file mode 100644
index 000000000000..b3466804ad5e
--- /dev/null
+++ b/drivers/usb/gadget/function/f_mud_pins.c
@@ -0,0 +1,962 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2020 Noralf Trønnes
+ */
+
+#include <linux/bitmap.h>
+#include <linux/configfs.h>
+#include <linux/device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/gpio/machine.h>
+#include <linux/idr.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+#include "f_mud.h"
+#include "../../../pinctrl/pinctrl-mud.h"
+
+/*
+ * Even though the host side is a pinctrl driver, the device side is a gpio consumer.
+ * That's because not all boards have a pin controller.
+ */
+
+/* Temporary debugging aid */
+#define fmdebug(fmt, ...) \
+do { \
+ if (1) \
+ printk(KERN_DEBUG fmt, ##__VA_ARGS__); \
+} while (0)
+
+static DEFINE_IDA(f_mud_pins_ida);
+
+struct f_mud_pins_cell_item {
+ struct list_head node;
+ unsigned int index;
+ struct config_group group;
+
+ struct mutex lock; /* Protect the values below */
+ int refcnt;
+
+ const char *name;
+ const char *chip;
+ int offset;
+};
+
+static inline struct f_mud_pins_cell_item *ci_to_f_mud_pins_cell_item(struct config_item *item)
+{
+ return container_of(to_config_group(item), struct f_mud_pins_cell_item, group);
+}
+
+struct f_mud_pins_lookup_device {
+ struct device dev;
+ int id;
+ struct f_mud_cell *cell;
+ struct gpiod_lookup_table *lookup;
+ const char **names;
+ unsigned int count;
+};
+
+struct f_mud_pins_pin {
+ struct f_mud_pins_cell *parent;
+ unsigned int index;
+ struct gpio_desc *gpio;
+ unsigned long dflags;
+ unsigned int debounce;
+#define DEBOUNCE_NOT_SET UINT_MAX
+ bool config_requested;
+ int irq;
+ int irqflags;
+};
+
+struct f_mud_pins_cell {
+ struct f_mud_cell cell;
+
+ struct mutex lock; /* Protect refcnt and items */
+ int refcnt;
+ struct list_head items;
+
+ struct f_mud_pins_lookup_device *ldev;
+ struct f_mud_pins_pin *pins;
+ unsigned int count;
+ spinlock_t irq_status_lock;
+ unsigned long *irq_status;
+};
+
+static inline struct f_mud_pins_cell *ci_to_f_mud_pins_cell(struct config_item *item)
+{
+ return container_of(to_config_group(item), struct f_mud_pins_cell, cell.group);
+}
+
+static inline struct f_mud_pins_cell *cell_to_pcell(struct f_mud_cell *cell)
+{
+ return container_of(cell, struct f_mud_pins_cell, cell);
+}
+
+static irqreturn_t f_mud_pins_gpio_irq_thread(int irq, void *p)
+{
+ struct f_mud_pins_pin *pin = p;
+ struct f_mud_pins_cell *pcell = pin->parent;
+
+ spin_lock(&pcell->irq_status_lock);
+ set_bit(pin->index, pcell->irq_status);
+ spin_unlock(&pcell->irq_status_lock);
+
+ fmdebug("%s(index=%u): irq_status=%*pb\n", __func__, pin->index,
+ pcell->count, pcell->irq_status);
+
+ f_mud_irq(pcell->ldev->cell);
+
+ return IRQ_HANDLED;
+}
+
+static int f_mud_pins_gpio_irq_request(struct f_mud_pins_cell *pcell, unsigned int index)
+{
+ struct f_mud_pins_pin *pin = &pcell->pins[index];
+ int ret, irq;
+
+ fmdebug("%s(index=%u)\n", __func__, index);
+
+ if (pin->irq)
+ return 0;
+
+ if (!pin->gpio || !pin->irqflags)
+ return -EINVAL;
+
+ ret = gpiod_get_direction(pin->gpio);
+ if (ret < 0)
+ return ret;
+ if (ret != 1)
+ return -EINVAL;
+
+ irq = gpiod_to_irq(pin->gpio);
+ fmdebug(" irq=%d\n", irq);
+ if (irq <= 0)
+ return -ENODEV;
+
+ ret = request_threaded_irq(irq, NULL, f_mud_pins_gpio_irq_thread,
+ pin->irqflags | IRQF_ONESHOT,
+ dev_name(&pcell->ldev->dev), pin);
+ if (ret)
+ return ret;
+
+ pin->irq = irq;
+
+ return 0;
+}
+
+static void f_mud_pins_gpio_irq_free(struct f_mud_pins_cell *pcell, unsigned int index)
+{
+ struct f_mud_pins_pin *pin = &pcell->pins[index];
+
+ fmdebug("%s(index=%u): irq=%d\n", __func__, index, pin->irq);
+
+ if (pin->irq) {
+ free_irq(pin->irq, pin);
+ pin->irq = 0;
+ }
+}
+
+static void f_mud_pins_gpio_irq_free_all(struct f_mud_pins_cell *pcell)
+{
+ unsigned int i;
+
+ for (i = 0; i < pcell->count; i++)
+ f_mud_pins_gpio_irq_free(pcell, i);
+}
+
+static int f_mud_pins_gpio_irq_type(struct f_mud_pins_cell *pcell, unsigned int index,
+ unsigned int val)
+{
+ struct f_mud_pins_pin *pin = &pcell->pins[index];
+
+ fmdebug("%s(index=%u, val=%u)\n", __func__, index, val);
+
+ switch (val) {
+ case MUD_PIN_IRQ_TYPE_EDGE_RISING:
+ pin->irqflags = IRQF_TRIGGER_RISING;
+ break;
+ case MUD_PIN_IRQ_TYPE_EDGE_FALLING:
+ pin->irqflags = IRQF_TRIGGER_FALLING;
+ break;
+ case MUD_PIN_IRQ_TYPE_EDGE_BOTH:
+ pin->irqflags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;
+ break;
+ case MUD_PIN_IRQ_TYPE_NONE:
+ pin->irqflags = IRQF_TRIGGER_NONE;
+ break;
+ default:
+ return -EINVAL;
+ };
+
+ return 0;
+}
+
+static void f_mud_pins_gpio_free(struct f_mud_pins_cell *pcell, unsigned int index)
+{
+ struct f_mud_pins_pin *pin = &pcell->pins[index];
+
+ fmdebug("%s(index=%u): gpio=%d, config_requested=%u\n", __func__, index,
+ pin->gpio ? desc_to_gpio(pin->gpio) : -1, pin->config_requested);
+
+ if (pin->config_requested)
+ return;
+
+ if (pin->gpio)
+ gpiod_put(pin->gpio);
+ pin->gpio = NULL;
+}
+
+/* When flags change re-request the gpio to enable the settings */
+static int f_mud_pins_gpio_request_do(struct f_mud_pins_cell *pcell, unsigned int index,
+ bool config, unsigned int debounce)
+{
+ struct f_mud_pins_pin *pin = &pcell->pins[index];
+ struct gpio_desc *gpio;
+ int ret;
+
+ fmdebug("%s(index=%u): lflags=%lu dflags=%lu\n", __func__, index,
+ pcell->ldev->lookup->table[index].flags, pin->dflags);
+
+ if (!pcell->pins[index].gpio && config)
+ pin->config_requested = true;
+
+ if (pcell->pins[index].gpio) {
+ gpiod_put(pcell->pins[index].gpio);
+ pcell->pins[index].gpio = NULL;
+ }
+
+ gpio = gpiod_get_index(&pcell->ldev->dev, NULL, index, pin->dflags);
+ if (IS_ERR(gpio)) {
+ ret = PTR_ERR(gpio);
+ fmdebug("failed to get gpio %u: ret=%d\n", index, ret);
+ return ret;
+ }
+ pin->gpio = gpio;
+ fmdebug(" gpios[%u]: gpionr %d\n", index, desc_to_gpio(gpio));
+
+ /* Debounce can be set through pinconf so it must be stored */
+ if (debounce == DEBOUNCE_NOT_SET)
+ debounce = pin->debounce;
+
+ if (debounce != DEBOUNCE_NOT_SET) {
+ ret = gpiod_set_debounce(pin->gpio, debounce);
+ if (ret)
+ return ret;
+
+ pin->debounce = debounce ? debounce : DEBOUNCE_NOT_SET;
+ }
+
+ return 0;
+}
+
+static int f_mud_pins_gpio_request_debounce(struct f_mud_pins_cell *pcell,
+ unsigned int index, unsigned int debounce)
+{
+ struct f_mud_pins_pin *pin = &pcell->pins[index];
+
+ if (pin->debounce == debounce)
+ return 0;
+
+ return f_mud_pins_gpio_request_do(pcell, index, true, debounce);
+}
+
+static int f_mud_pins_gpio_request_dflag(struct f_mud_pins_cell *pcell, unsigned int index,
+ enum gpiod_flags dflag, bool dval, bool config)
+{
+ struct f_mud_pins_pin *pin = &pcell->pins[index];
+ bool curr_dflag = pin->dflags & dflag;
+ bool changed = false;
+
+ fmdebug("%s(index=%u): dflag=%u dval=%u\n", __func__, index, dflag, dval);
+
+ if (curr_dflag != dval) {
+ if (dval)
+ pin->dflags |= dflag;
+ else
+ pin->dflags &= ~dflag;
+ changed = true;
+ }
+
+ if (pin->gpio && !changed)
+ return 0;
+
+ return f_mud_pins_gpio_request_do(pcell, index, config, DEBOUNCE_NOT_SET);
+}
+
+static int f_mud_pins_gpio_request_lflag(struct f_mud_pins_cell *pcell, unsigned int index,
+ enum gpio_lookup_flags lflag, bool lval,
+ bool config)
+{
+ struct gpiod_lookup *lentry = &pcell->ldev->lookup->table[index];
+ struct f_mud_pins_pin *pin = &pcell->pins[index];
+ bool curr_lflag = lentry->flags & lflag;
+ bool changed = false;
+
+ fmdebug("%s(index=%u): lflag=%u lval=%u\n", __func__, index, lflag, lval);
+
+ if (curr_lflag != lval) {
+ if (lval)
+ lentry->flags |= lflag;
+ else
+ lentry->flags &= ~lflag;
+ changed = true;
+ }
+
+ if (pin->gpio && !changed)
+ return 0;
+
+ return f_mud_pins_gpio_request_do(pcell, index, config, DEBOUNCE_NOT_SET);
+}
+
+static int f_mud_pins_write_gpio_config(struct f_mud_pins_cell *pcell, unsigned int index,
+ unsigned int offset, unsigned int val)
+{
+ struct f_mud_pins_pin *pin;
+ int ret = -ENOTSUPP;
+
+ fmdebug("%s(index=%u, offset=0x%02x, val=%u)\n", __func__, index, offset, val);
+
+ pin = &pcell->pins[index];
+
+ switch (offset) {
+ case MUD_PIN_CONFIG_BIAS_PULL_DOWN:
+ if (!val)
+ return -ENOTSUPP;
+ ret = f_mud_pins_gpio_request_lflag(pcell, index, GPIO_PULL_DOWN, val, true);
+ break;
+ case MUD_PIN_CONFIG_BIAS_PULL_UP:
+ if (!val)
+ return -ENOTSUPP;
+ ret = f_mud_pins_gpio_request_lflag(pcell, index, GPIO_PULL_UP, val, true);
+ break;
+ case MUD_PIN_CONFIG_DRIVE_OPEN_DRAIN:
+ ret = f_mud_pins_gpio_request_lflag(pcell, index, GPIO_OPEN_DRAIN, 1, true);
+ break;
+ case MUD_PIN_CONFIG_DRIVE_OPEN_SOURCE:
+ ret = f_mud_pins_gpio_request_lflag(pcell, index, GPIO_OPEN_SOURCE, 1, true);
+ break;
+ case MUD_PIN_CONFIG_DRIVE_PUSH_PULL:
+ ret = f_mud_pins_gpio_request_dflag(pcell, index, GPIOD_IN, 0, true);
+ break;
+ case MUD_PIN_CONFIG_INPUT_DEBOUNCE:
+ ret = f_mud_pins_gpio_request_debounce(pcell, index, val);
+ break;
+ case MUD_PIN_CONFIG_INPUT_ENABLE:
+ ret = f_mud_pins_gpio_request_dflag(pcell, index, GPIOD_IN, val, true);
+ break;
+ case MUD_PIN_CONFIG_OUTPUT:
+ val = val ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
+ ret = f_mud_pins_gpio_request_dflag(pcell, index, val, 1, true);
+ break;
+ case MUD_PIN_CONFIG_PERSIST_STATE:
+ ret = f_mud_pins_gpio_request_lflag(pcell, index, GPIO_TRANSITORY, val, true);
+ break;
+ }
+
+ return ret;
+}
+
+static int f_mud_pins_write_gpio(struct f_mud_pins_cell *pcell, unsigned int regnr,
+ const void *buf, size_t len)
+{
+ unsigned int regbase = regnr - MUD_PINCTRL_REG_PIN_BASE;
+ unsigned int offset = regbase % MUD_PINCTRL_PIN_BLOCK_SIZE;
+ unsigned int index = regbase / MUD_PINCTRL_PIN_BLOCK_SIZE;
+ size_t count = len / sizeof(u32);
+ struct f_mud_pins_pin *pin;
+ const __le32 *buf32 = buf;
+ u32 val;
+ int ret;
+
+ fmdebug("%s(len=%zu): offset=0x%02x index=%u\n", __func__, len, offset, index);
+
+ if (index >= pcell->count) {
+ fmdebug("%s: gpio index out of bounds: %u\n", __func__, index);
+ return -EINVAL;
+ }
+
+ while (count--) {
+ pin = &pcell->pins[index];
+ val = le32_to_cpup(buf32++);
+ ret = 0;
+
+ switch (offset++) {
+ case MUD_PIN_CONFIG_BIAS_BUS_HOLD ... MUD_PIN_CONFIG_END:
+ return f_mud_pins_write_gpio_config(pcell, index, offset - 1, val);
+
+ case MUD_PIN_GPIO_REQUEST:
+ if (val != 1)
+ return -EINVAL;
+ /* Persistence is the default so set it from the start */
+ ret = f_mud_pins_gpio_request_lflag(pcell, index, GPIO_TRANSITORY,
+ 0, false);
+ break;
+ case MUD_PIN_GPIO_FREE:
+ if (val != 1)
+ return -EINVAL;
+ f_mud_pins_gpio_free(pcell, index);
+ break;
+
+ case MUD_PIN_DIRECTION:
+ if (!pin)
+ return -EINVAL;
+
+ if (val == MUD_PIN_DIRECTION_INPUT) {
+ ret = gpiod_direction_input(pin->gpio);
+ } else {
+ int value = !!(val & MUD_PIN_DIRECTION_OUTPUT_HIGH);
+
+ ret = gpiod_direction_output(pin->gpio, value);
+ }
+ break;
+ case MUD_PIN_LEVEL:
+ if (pin)
+ gpiod_set_value_cansleep(pin->gpio, val);
+ break;
+ case MUD_PIN_IRQ_TYPE:
+ ret = f_mud_pins_gpio_irq_type(pcell, index, val);
+ break;
+ case MUD_PIN_IRQ_ENABLED:
+ if (val)
+ ret = f_mud_pins_gpio_irq_request(pcell, index);
+ else
+ f_mud_pins_gpio_irq_free(pcell, index);
+ break;
+ default:
+ pr_err("%s: unknown register: 0x%x\n", __func__, regnr);
+ return -EINVAL;
+ }
+
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int f_mud_pins_writereg(struct f_mud_cell *cell, unsigned int regnr,
+ const void *buf, size_t len, u8 compression)
+{
+ struct f_mud_pins_cell *pcell = cell_to_pcell(cell);
+
+ fmdebug("%s(regnr=0x%02x, len=%zu)\n", __func__, regnr, len);
+
+ if (regnr >= MUD_PINCTRL_REG_PIN_BASE)
+ return f_mud_pins_write_gpio(pcell, regnr, buf, len);
+
+ return -EINVAL;
+}
+
+static int f_mud_pins_read_gpio(struct f_mud_pins_cell *pcell, unsigned int regnr,
+ void *buf, size_t len)
+{
+ unsigned int regbase = regnr - MUD_PINCTRL_REG_PIN_BASE;
+ unsigned int offset = regbase % MUD_PINCTRL_PIN_BLOCK_SIZE;
+ unsigned int index = regbase / MUD_PINCTRL_PIN_BLOCK_SIZE;
+ size_t count = len / sizeof(u32);
+ struct f_mud_pins_pin *pin;
+ struct gpio_desc *gpio;
+ __le32 *buf32 = buf;
+ u32 val;
+ int ret;
+
+ fmdebug("%s(len=%zu): offset=0x%02x index=%u\n", __func__, len, offset, index);
+
+ if (index >= pcell->count) {
+ fmdebug("%s: gpio index out of bounds: %u\n", __func__, index);
+ return -EINVAL;
+ }
+
+ if (offset >= MUD_PIN_NAME && (offset + count - 1) <= MUD_PIN_NAME_END) {
+ size_t start = (offset - MUD_PIN_NAME) * sizeof(u32);
+ char name[MUD_PIN_NAME_LEN];
+
+ strscpy_pad(name, pcell->ldev->names[index], MUD_PIN_NAME_LEN);
+ fmdebug(" name=%*ph\n", MUD_PIN_NAME_LEN, name);
+ memcpy(buf, name + start, len);
+
+ return 0;
+ }
+
+ pin = &pcell->pins[index];
+
+ while (count--) {
+ switch (offset++) {
+ case MUD_PIN_DIRECTION:
+ /*
+ * Host side gpiochip_add_data_with_key() calls ->get_direction
+ * without requesting the gpio first.
+ */
+ gpio = pin->gpio;
+ if (!gpio) {
+ /* non gpio pins will fail here, but that's fine */
+ ret = f_mud_pins_gpio_request_lflag(pcell, index,
+ 0, 0, false);
+ if (ret)
+ return ret;
+ }
+ ret = gpiod_get_direction(pin->gpio);
+ if (!gpio)
+ f_mud_pins_gpio_free(pcell, index);
+ if (ret < 0)
+ return ret;
+ val = ret ? MUD_PIN_DIRECTION_INPUT : MUD_PIN_DIRECTION_OUTPUT;
+ break;
+ case MUD_PIN_LEVEL:
+ if (!pin->gpio)
+ return -EINVAL;
+ ret = gpiod_get_value_cansleep(pin->gpio);
+ if (ret < 0)
+ return ret;
+ val = ret;
+ break;
+ case MUD_PIN_IRQ_TYPES:
+ /* FIXME: Is it possible to get this info somewhere? */
+ val = MUD_PIN_IRQ_TYPE_EDGE_BOTH;
+ break;
+ default:
+ pr_err("%s: unknown register: 0x%x\n", __func__, regnr);
+ return -EINVAL;
+ }
+
+ *(buf32++) = cpu_to_le32(val);
+ }
+
+ return 0;
+}
+
+static int f_mud_pins_readreg(struct f_mud_cell *cell, unsigned int regnr,
+ void *buf, size_t *len, u8 compression)
+{
+ struct f_mud_pins_cell *pcell = cell_to_pcell(cell);
+ size_t count = *len / sizeof(u32);
+ __le32 *buf32 = buf;
+
+ fmdebug("%s(regnr=0x%02x, len=%zu)\n", __func__, regnr, *len);
+
+ if (regnr >= MUD_PINCTRL_REG_PIN_BASE)
+ return f_mud_pins_read_gpio(pcell, regnr, buf, *len);
+
+ if (regnr >= MUD_PINCTRL_REG_IRQ_STATUS &&
+ regnr <= MUD_PINCTRL_REG_IRQ_STATUS_END) {
+ unsigned int nregs = DIV_ROUND_UP(pcell->count, sizeof(u32));
+ unsigned int offset = regnr - MUD_PINCTRL_REG_IRQ_STATUS;
+ unsigned int i, end = min_t(unsigned int, count, nregs);
+ u32 irqvals[MUD_PINCTRL_MAX_NUM_PINS / sizeof(u32)];
+
+ if (count > (nregs - offset))
+ return -EINVAL;
+
+ bitmap_to_arr32(irqvals, pcell->irq_status, pcell->count);
+
+ fmdebug(" irq_status=%*pb irqvals=%*ph\n", pcell->count,
+ pcell->irq_status, nregs, irqvals);
+
+ for (i = offset; i < end; i++)
+ *buf32++ = cpu_to_le32(irqvals[i]);
+
+ return 0;
+ }
+
+ if (regnr == MUD_PINCTRL_REG_NUM_PINS && count == 1) {
+ *buf32 = cpu_to_le32(pcell->count);
+ return 0;
+ }
+
+ fmdebug("%s: unknown register 0x%x\n", __func__, regnr);
+
+ return -EINVAL;
+}
+
+static void f_mud_pins_disable(struct f_mud_cell *cell)
+{
+ struct f_mud_pins_cell *pcell = cell_to_pcell(cell);
+
+ f_mud_pins_gpio_irq_free_all(pcell);
+ /*
+ * FIXME: Free requested gpios as well?
+ * Or should they survive on unplug on a powered board?
+ */
+}
+
+static void f_mud_pins_lookup_device_release(struct device *dev)
+{
+ struct f_mud_pins_lookup_device *ldev =
+ container_of(dev, struct f_mud_pins_lookup_device, dev);
+
+ fmdebug("%s: ldev=%px\n", __func__, ldev);
+
+ if (ldev->lookup) {
+ struct gpiod_lookup *p;
+
+ if (ldev->lookup->dev_id)
+ gpiod_remove_lookup_table(ldev->lookup);
+
+ for (p = &ldev->lookup->table[0]; p->chip_label; p++)
+ kfree(p->chip_label);
+ kfree(ldev->lookup);
+ }
+
+ if (ldev->names) {
+ unsigned int i;
+
+ for (i = 0; i < ldev->count; i++)
+ kfree(ldev->names[i]);
+ kfree(ldev->names);
+ }
+
+ ida_free(&f_mud_pins_ida, ldev->id);
+ kfree(ldev);
+}
+
+static int f_mud_pins_looup_device_create(struct f_mud_pins_cell *pcell)
+{
+ struct f_mud_pins_lookup_device *ldev;
+ struct f_mud_pins_cell_item *fitem;
+ unsigned int max_index = 0;
+ int ret;
+
+ fmdebug("%s: %px\n", __func__, pcell);
+
+ ldev = kzalloc(sizeof(*ldev), GFP_KERNEL);
+ if (!ldev)
+ return -ENOMEM;
+
+ fmdebug("%s: ldev=%px\n", __func__, ldev);
+
+ ldev->id = ida_alloc(&f_mud_pins_ida, GFP_KERNEL);
+ if (ldev->id < 0) {
+ kfree(ldev);
+ return ldev->id;
+ }
+
+ ldev->cell = &pcell->cell;
+ ldev->dev.release = f_mud_pins_lookup_device_release;
+ dev_set_name(&ldev->dev, "f_mud_pins-%d", ldev->id);
+
+ ret = device_register(&ldev->dev);
+ if (ret) {
+ put_device(&ldev->dev);
+ return ret;
+ }
+
+ mutex_lock(&pcell->lock);
+
+ list_for_each_entry(fitem, &pcell->items, node) {
+ max_index = max(max_index, fitem->index);
+ ldev->count++;
+ }
+
+ if (!ldev->count) {
+ ret = -ENOENT;
+ goto out_unlock;
+ }
+
+ if (ldev->count != max_index + 1) {
+ pr_err("Pin indices are not continuous\n");
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+
+ ldev->names = kcalloc(ldev->count, sizeof(*ldev->names), GFP_KERNEL);
+ ldev->lookup = kzalloc(struct_size(ldev->lookup, table, ldev->count + 1),
+ GFP_KERNEL);
+ if (!ldev->lookup || !ldev->names) {
+ ret = -ENOMEM;
+ goto out_unlock;
+ }
+
+ ret = 0;
+ list_for_each_entry(fitem, &pcell->items, node) {
+ struct gpiod_lookup *entry = &ldev->lookup->table[fitem->index];
+
+ mutex_lock(&fitem->lock);
+
+ if (!fitem->name) {
+ pr_err("Missing name for pin %u\n", fitem->index);
+ ret = -EINVAL;
+ goto out_unlock_pin;
+ }
+
+ ldev->names[fitem->index] = kstrdup(fitem->name, GFP_KERNEL);
+ if (!ldev->names[fitem->index]) {
+ ret = -ENOMEM;
+ goto out_unlock_pin;
+ }
+
+ /* Skip adding to lookup if the pin has no gpio function */
+ if (!fitem->chip)
+ goto out_unlock_pin;
+
+ entry->idx = fitem->index;
+ entry->chip_hwnum = fitem->offset;
+
+ entry->chip_label = kstrdup(fitem->chip, GFP_KERNEL);
+ if (!entry->chip_label) {
+ ret = -ENOMEM;
+ goto out_unlock_pin;
+ }
+
+ fmdebug(" %u: chip=%s hwnum=%u name=%s\n", entry->idx,
+ entry->chip_label, entry->chip_hwnum, ldev->names[fitem->index]);
+out_unlock_pin:
+ mutex_unlock(&fitem->lock);
+ if (ret)
+ goto out_unlock;
+ }
+
+ ldev->lookup->dev_id = dev_name(&ldev->dev);
+ gpiod_add_lookup_table(ldev->lookup);
+
+ pcell->ldev = ldev;
+ pcell->count = ldev->count;
+
+out_unlock:
+ mutex_unlock(&pcell->lock);
+
+ if (ret)
+ device_unregister(&ldev->dev);
+
+ return ret;
+}
+
+static void f_mud_pins_lookup_device_destroy(struct f_mud_pins_cell *pcell)
+{
+ if (pcell->ldev) {
+ device_unregister(&pcell->ldev->dev);
+ pcell->ldev = NULL;
+ }
+}
+
+static int f_mud_pins_bind(struct f_mud_cell *cell)
+{
+ struct f_mud_pins_cell *pcell = cell_to_pcell(cell);
+ unsigned int i;
+ int ret;
+
+ fmdebug("%s: %px\n", __func__, pcell);
+
+ ret = f_mud_pins_looup_device_create(pcell);
+ if (ret)
+ return ret;
+
+ spin_lock_init(&pcell->irq_status_lock);
+ pcell->irq_status = bitmap_zalloc(pcell->count, GFP_KERNEL);
+ if (!pcell->irq_status) {
+ ret = -ENOMEM;
+ goto error_free;
+ }
+
+ pcell->pins = kcalloc(pcell->count, sizeof(*pcell->pins), GFP_KERNEL);
+ if (!pcell->pins) {
+ ret = -ENOMEM;
+ goto error_free;
+ }
+
+ for (i = 0; i < pcell->count; i++) {
+ struct f_mud_pins_pin *pin = &pcell->pins[i];
+
+ pin->parent = pcell;
+ pin->index = i;
+ pin->debounce = DEBOUNCE_NOT_SET;
+ }
+
+ return 0;
+
+error_free:
+ kfree(pcell->pins);
+ f_mud_pins_lookup_device_destroy(pcell);
+
+ return ret;
+}
+
+static void f_mud_pins_unbind(struct f_mud_cell *cell)
+{
+ struct f_mud_pins_cell *pcell = cell_to_pcell(cell);
+ unsigned int i;
+
+ fmdebug("%s:\n", __func__);
+
+ if (pcell->pins) {
+ for (i = 0; i < pcell->count; i++) {
+ if (pcell->pins[i].gpio) {
+ fmdebug(" gpiod_put: %u\n", i);
+ gpiod_put(pcell->pins[i].gpio);
+ }
+ }
+
+ kfree(pcell->pins);
+ }
+
+ bitmap_free(pcell->irq_status);
+
+ f_mud_pins_lookup_device_destroy(pcell);
+}
+
+static void f_mud_pins_cell_item_item_release(struct config_item *item)
+{
+ struct f_mud_pins_cell_item *fitem = ci_to_f_mud_pins_cell_item(item);
+
+ fmdebug("%s: fitem=%px\n", __func__, fitem);
+
+ kfree(fitem->name);
+ kfree(fitem->chip);
+ kfree(fitem);
+}
+
+F_MUD_OPT_STR(f_mud_pins_cell_item, name);
+F_MUD_OPT_STR(f_mud_pins_cell_item, chip);
+F_MUD_OPT_INT(f_mud_pins_cell_item, offset, 0, INT_MAX);
+
+static struct configfs_attribute *f_mud_pins_cell_item_attrs[] = {
+ &f_mud_pins_cell_item_attr_name,
+ &f_mud_pins_cell_item_attr_chip,
+ &f_mud_pins_cell_item_attr_offset,
+ NULL,
+};
+
+static struct configfs_item_operations f_mud_pins_cell_item_item_ops = {
+ .release = f_mud_pins_cell_item_item_release,
+};
+
+static const struct config_item_type f_mud_pins_cell_item_func_type = {
+ .ct_item_ops = &f_mud_pins_cell_item_item_ops,
+ .ct_attrs = f_mud_pins_cell_item_attrs,
+ .ct_owner = THIS_MODULE,
+};
+
+static struct config_group *f_mud_pins_make_group(struct config_group *group,
+ const char *name)
+{
+ struct f_mud_pins_cell *pcell = ci_to_f_mud_pins_cell(&group->cg_item);
+ struct f_mud_pins_cell_item *fitem;
+ const char *prefix = "pin.";
+ struct config_group *grp;
+ int ret, index;
+
+ fmdebug("%s: name=%s\n", __func__, name);
+
+ mutex_lock(&pcell->lock);
+ fmdebug("%s: pcell=%px pcell->refcnt=%d\n", __func__, pcell, pcell->refcnt);
+ if (pcell->refcnt) {
+ grp = ERR_PTR(-EBUSY);
+ goto out_unlock;
+ }
+
+ if (strstr(name, prefix) != name) {
+ pr_err("Missing prefix '%s' in name: '%s'\n", prefix, name);
+ grp = ERR_PTR(-EINVAL);
+ goto out_unlock;
+ }
+
+ ret = kstrtoint(name + strlen(prefix), 10, &index);
+ if (ret) {
+ pr_err("Failed to parse index in name: '%s'\n", name);
+ grp = ERR_PTR(ret);
+ goto out_unlock;
+ }
+
+ fitem = kzalloc(sizeof(*fitem), GFP_KERNEL);
+ fmdebug(" pin=%px\n", fitem);
+ if (!fitem) {
+ grp = ERR_PTR(-ENOMEM);
+ goto out_unlock;
+ }
+
+ fitem->index = index;
+ grp = &fitem->group;
+
+ config_group_init_type_name(grp, "", &f_mud_pins_cell_item_func_type);
+
+ list_add(&fitem->node, &pcell->items);
+out_unlock:
+ mutex_unlock(&pcell->lock);
+
+ return grp;
+}
+
+static void f_mud_pins_drop_item(struct config_group *group, struct config_item *item)
+{
+ struct f_mud_pins_cell *pcell = ci_to_f_mud_pins_cell(&group->cg_item);
+ struct f_mud_pins_cell_item *fitem = ci_to_f_mud_pins_cell_item(item);
+
+ fmdebug("%s: pcell=%px fitem=%px\n", __func__, pcell, fitem);
+
+ mutex_lock(&pcell->lock);
+ list_del(&fitem->node);
+ mutex_unlock(&pcell->lock);
+
+ config_item_put(item);
+}
+
+static struct configfs_group_operations f_mud_pins_group_ops = {
+ .make_group = f_mud_pins_make_group,
+ .drop_item = f_mud_pins_drop_item,
+};
+
+static struct configfs_item_operations f_mud_pins_item_ops = {
+ .release = f_mud_cell_item_release,
+};
+
+static const struct config_item_type f_mud_pins_func_type = {
+ .ct_item_ops = &f_mud_pins_item_ops,
+ .ct_group_ops = &f_mud_pins_group_ops,
+ .ct_owner = THIS_MODULE,
+};
+
+static void f_mud_pins_free(struct f_mud_cell *cell)
+{
+ struct f_mud_pins_cell *pcell = container_of(cell, struct f_mud_pins_cell, cell);
+
+ fmdebug("%s: pcell=%px\n", __func__, pcell);
+
+ mutex_destroy(&pcell->lock);
+ kfree(pcell);
+}
+
+static struct f_mud_cell *f_mud_pins_alloc(void)
+{
+ struct f_mud_pins_cell *pcell;
+
+ pcell = kzalloc(sizeof(*pcell), GFP_KERNEL);
+ fmdebug("%s: pcell=%px\n", __func__, pcell);
+ if (!pcell)
+ return ERR_PTR(-ENOMEM);
+
+ mutex_init(&pcell->lock);
+ INIT_LIST_HEAD(&pcell->items);
+ config_group_init_type_name(&pcell->cell.group, "", &f_mud_pins_func_type);
+
+ fmdebug("%s: cell=%px\n", __func__, &pcell->cell);
+
+ return &pcell->cell;
+}
+
+static const struct f_mud_cell_ops f_mud_pins_ops = {
+ .name = "mud-pins",
+ .owner = THIS_MODULE,
+
+ .interrupt_interval_ms = 100,
+
+ .alloc = f_mud_pins_alloc,
+ .free = f_mud_pins_free,
+ .bind = f_mud_pins_bind,
+ .unbind = f_mud_pins_unbind,
+
+ .regval_bytes = 4,
+ .max_transfer_size = 64,
+
+ .disable = f_mud_pins_disable,
+ .readreg = f_mud_pins_readreg,
+ .writereg = f_mud_pins_writereg,
+};
+
+DECLARE_F_MUD_CELL_INIT(f_mud_pins_ops);
+
+MODULE_AUTHOR("Noralf Trønnes");
+MODULE_LICENSE("GPL");
--
2.23.0
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