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Date:      Mon, 9 Jan 2017 01:54:36 +0000 (UTC)
From:      Ian Lepore <ian@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r311734 - in head/sys: conf dev/sdhci
Message-ID:  <201701090154.v091saIa006231@repo.freebsd.org>

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Author: ian
Date: Mon Jan  9 01:54:36 2017
New Revision: 311734
URL: https://svnweb.freebsd.org/changeset/base/311734

Log:
  Add new helper routines for sdhci bridge drivers that use gpio pins for
  card presence and write protect switch detection.
  
  A bridge driver just needs to call the setup routine in its attach(), the
  teardown in its detach(), and write a couple tiny glue functions to connect
  the sdhci interface functions to the new helper functions.  This is not
  extensively documented, but multiple examples will exist real soon.

Added:
  head/sys/dev/sdhci/sdhci_fdt_gpio.c   (contents, props changed)
  head/sys/dev/sdhci/sdhci_fdt_gpio.h   (contents, props changed)
Modified:
  head/sys/conf/files

Modified: head/sys/conf/files
==============================================================================
--- head/sys/conf/files	Mon Jan  9 01:47:00 2017	(r311733)
+++ head/sys/conf/files	Mon Jan  9 01:54:36 2017	(r311734)
@@ -2824,6 +2824,7 @@ dev/scc/scc_dev_quicc.c		optional scc qu
 dev/scc/scc_dev_sab82532.c	optional scc
 dev/scc/scc_dev_z8530.c		optional scc
 dev/sdhci/sdhci.c		optional sdhci
+dev/sdhci/sdhci_fdt_gpio.c	optional sdhci fdt gpio
 dev/sdhci/sdhci_if.m		optional sdhci
 dev/sdhci/sdhci_pci.c		optional sdhci pci
 dev/sf/if_sf.c			optional sf pci

Added: head/sys/dev/sdhci/sdhci_fdt_gpio.c
==============================================================================
--- /dev/null	00:00:00 1970	(empty, because file is newly added)
+++ head/sys/dev/sdhci/sdhci_fdt_gpio.c	Mon Jan  9 01:54:36 2017	(r311734)
@@ -0,0 +1,256 @@
+/*-
+ * Copyright (c) 2017 Ian Lepore <ian@freebsd.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/*
+ * Support routines usable by any SoC sdhci bridge driver that uses gpio pins
+ * for card detect and write protect, and uses FDT data to describe those pins.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/bus.h>
+#include <sys/gpio.h>
+#include <sys/sysctl.h>
+#include <sys/taskqueue.h>
+
+#include <dev/gpio/gpiobusvar.h>
+#include <dev/mmc/bridge.h>
+#include <dev/ofw/ofw_bus.h>
+#include <dev/ofw/ofw_bus_subr.h>
+#include <dev/sdhci/sdhci.h>
+#include <dev/sdhci/sdhci_fdt_gpio.h>
+
+struct sdhci_fdt_gpio {
+	device_t		dev;
+	struct sdhci_slot *	slot;
+	gpio_pin_t		wp_pin;
+	gpio_pin_t		cd_pin;
+	void *			cd_ihandler;
+	struct resource *	cd_ires;
+	int			cd_irid;
+	bool			wp_disabled;
+	bool			wp_inverted;
+	bool			cd_disabled;
+	bool			cd_inverted;
+};
+
+/*
+ * Card detect interrupt handler.
+ */
+static void
+cd_intr(void *arg)
+{
+	struct sdhci_fdt_gpio *gpio = arg;
+
+	sdhci_handle_card_present(gpio->slot, sdhci_fdt_gpio_get_present(gpio));
+}
+
+/*
+ * Card detect setup.
+ */
+static void
+cd_setup(struct sdhci_fdt_gpio *gpio, phandle_t node)
+{
+	int pincaps;
+	device_t dev;
+	const char *cd_mode_str;
+
+	dev = gpio->dev;
+
+	/*
+	 * If the device is flagged as non-removable, set that slot option, and
+	 * set a flag to make sdhci_fdt_gpio_get_present() always return true.
+	 */
+	if (OF_hasprop(node, "non-removable")) {
+		gpio->slot->opt |= SDHCI_NON_REMOVABLE;
+		gpio->cd_disabled = true;
+		if (bootverbose)
+			device_printf(dev, "Non-removable media");
+		return;
+	}
+
+	/*
+	 * If there is no cd-gpios property, then presumably the hardware
+	 * PRESENT_STATE register and interrupts will reflect card state
+	 * properly, and there's nothing more for us to do.  Our get_present()
+	 * will return sdhci_generic_get_card_present() because cd_pin is NULL.
+	 *
+	 * If there is a property, make sure we can read the pin.
+	 */
+	if (gpio_pin_get_by_ofw_property(dev, node, "cd-gpios", &gpio->cd_pin))
+		return;
+
+	if (gpio_pin_getcaps(gpio->cd_pin, &pincaps) != 0 ||
+	    !(pincaps & GPIO_PIN_INPUT)) {
+		device_printf(dev, "Cannot read card-detect gpio pin; "
+		    "setting card-always-present flag.\n");
+		gpio->cd_disabled = true;
+		return;
+	}
+
+	if (OF_hasprop(node, "cd-inverted"))
+		gpio->cd_inverted = true;
+
+	/*
+	 * If the pin can trigger an interrupt on both rising and falling edges,
+	 * we can use it to detect card presence changes.  If not, we'll request
+	 * card presence polling instead of using interrupts.
+	 */
+	if (!(pincaps & GPIO_INTR_EDGE_BOTH)) {
+		if (bootverbose)
+			device_printf(dev, "Cannot configure "
+			    "GPIO_INTR_EDGE_BOTH for card detect\n");
+		goto without_interrupts;
+	}
+
+	/*
+	 * Create an interrupt resource from the pin and set up the interrupt.
+	 */
+	if ((gpio->cd_ires = gpio_alloc_intr_resource(dev, &gpio->cd_irid,
+	    RF_ACTIVE, gpio->cd_pin, GPIO_INTR_EDGE_BOTH)) == NULL) {
+		if (bootverbose)
+			device_printf(dev, "Cannot allocate an IRQ for card "
+			    "detect GPIO\n");
+		goto without_interrupts;
+	}
+
+	if (bus_setup_intr(dev, gpio->cd_ires, INTR_TYPE_BIO | INTR_MPSAFE,
+	    NULL, cd_intr, gpio, &gpio->cd_ihandler) != 0) {
+		device_printf(dev, "Unable to setup card-detect irq handler\n");
+		gpio->cd_ihandler = NULL;
+		goto without_interrupts;
+	}
+
+without_interrupts:
+
+	/*
+	 * If we have a readable gpio pin, but didn't successfully configure
+	 * gpio interrupts, ask the sdhci driver to poll from a callout.
+	 */
+	if (gpio->cd_ihandler == NULL) {
+		cd_mode_str = "polling";
+		gpio->slot->quirks |= SDHCI_QUIRK_POLL_CARD_PRESENT;
+	} else {
+		cd_mode_str = "interrupts";
+	}
+
+	if (bootverbose) {
+		device_printf(dev, "Card presence detect on %s pin %u, "
+		    "configured for %s.\n",
+		    device_get_nameunit(gpio->cd_pin->dev), gpio->cd_pin->pin,
+		    cd_mode_str);
+	}
+}
+
+/*
+ * Write protect setup.
+ */
+static void
+wp_setup(struct sdhci_fdt_gpio *gpio, phandle_t node)
+{
+	device_t dev;
+
+	dev = gpio->dev;
+
+	if (OF_hasprop(node, "wp-disable"))
+		return;
+
+	if (gpio_pin_get_by_ofw_property(dev, node, "wp-gpios", &gpio->wp_pin))
+		return;
+
+	if (OF_hasprop(node, "wp-inverted"))
+		gpio->wp_inverted = true;
+
+	if (bootverbose)
+		device_printf(dev, "Write protect switch on %s pin %u\n",
+		    device_get_nameunit(gpio->cd_pin->dev), gpio->cd_pin->pin);
+}
+
+struct sdhci_fdt_gpio *
+sdhci_fdt_gpio_setup(device_t dev, struct sdhci_slot *slot)
+{
+	phandle_t node;
+	struct sdhci_fdt_gpio *gpio;
+
+	gpio = malloc(sizeof(*gpio), M_DEVBUF, M_ZERO | M_WAITOK);
+	gpio->dev  = dev;
+	gpio->slot = slot;
+
+	node = ofw_bus_get_node(dev);
+
+	wp_setup(gpio, node);
+	cd_setup(gpio, node);
+
+	return (gpio);
+}
+
+void
+sdhci_fdt_gpio_teardown(struct sdhci_fdt_gpio *gpio)
+{
+
+	if (gpio == NULL)
+		return;
+
+	if (gpio->cd_ihandler != NULL) {
+		bus_teardown_intr(gpio->dev, gpio->cd_ires, gpio->cd_ihandler);
+	}
+
+	free(gpio, M_DEVBUF);
+}
+
+bool
+sdhci_fdt_gpio_get_present(struct sdhci_fdt_gpio *gpio)
+{
+	bool pinstate;
+
+	if (gpio->cd_disabled)
+		return (true);
+
+	if (gpio->cd_pin == NULL)
+		return (sdhci_generic_get_card_present(gpio->slot->bus,
+		    gpio->slot));
+
+	gpio_pin_is_active(gpio->cd_pin, &pinstate);
+
+	return (pinstate ^ gpio->cd_inverted);
+}
+
+int
+sdhci_fdt_gpio_get_readonly(struct sdhci_fdt_gpio *gpio)
+{
+	bool pinstate;
+
+	if (gpio->wp_disabled)
+		return (false);
+
+	if (gpio->wp_pin == NULL)
+		return (sdhci_generic_get_ro(gpio->slot->bus, gpio->slot->dev));
+
+	gpio_pin_is_active(gpio->wp_pin, &pinstate);
+
+	return (pinstate ^ gpio->wp_inverted);
+}

Added: head/sys/dev/sdhci/sdhci_fdt_gpio.h
==============================================================================
--- /dev/null	00:00:00 1970	(empty, because file is newly added)
+++ head/sys/dev/sdhci/sdhci_fdt_gpio.h	Mon Jan  9 01:54:36 2017	(r311734)
@@ -0,0 +1,69 @@
+/*-
+ * Copyright (c) 2017 Ian Lepore <ian@freebsd.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+/*
+ * Support routines usable by any SoC sdhci bridge driver that uses gpio pins
+ * for card detect and/or write protect, and uses FDT data to describe those
+ * pins.  A bridge driver need only supply a couple 2-line forwarding functions
+ * to connect the get_present and get_readonly accessors to the corresponding
+ * driver interface functions, and add setup/teardown calls to its attach and
+ * detach functions.
+ */
+
+#ifndef	_SDHCI_FDT_GPIO_H_
+#define	_SDHCI_FDT_GPIO_H_
+
+struct sdhci_slot;
+struct sdhci_fdt_gpio;
+
+/*
+ * sdhci_fdt_gpio_setup()
+ * sdhci_fdt_gpio_teardown()
+ *
+ * Process FDT properties that use gpio pins and set up interrupt handling (if
+ * supported by hardware) and accessor functions to read the pins.
+ *
+ * Setup cannot fail.  If the properties are not present, the accessors will
+ * return the values from standard sdhci registers.  If the gpio controller
+ * can't trigger interrupts on both edges, it configures the slot to use polling
+ * for card presence detection.  If it can't access the gpio pin at all it sets
+ * up the get_present() accessor to always return true.  Likewise the
+ * get_readonly() accessor always returns false if its pin can't be accessed.
+ */
+struct sdhci_fdt_gpio *sdhci_fdt_gpio_setup(device_t dev, struct sdhci_slot *slot);
+void sdhci_fdt_gpio_teardown(struct sdhci_fdt_gpio *gpio);
+
+/*
+ * sdhci_fdt_gpio_get_present()
+ * sdhci_fdt_gpio_get_readonly()
+ *
+ * Gpio pin state accessor functions.
+ */
+bool sdhci_fdt_gpio_get_present(struct sdhci_fdt_gpio *gpio);
+int  sdhci_fdt_gpio_get_readonly(struct sdhci_fdt_gpio *gpio);
+
+#endif



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