From patchwork Mon Oct 6 16:48:57 2008 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anton Vorontsov X-Patchwork-Id: 2932 X-Patchwork-Delegate: galak@kernel.crashing.org Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from ozlabs.org (localhost [127.0.0.1]) by ozlabs.org (Postfix) with ESMTP id A088CDE199 for ; Tue, 7 Oct 2008 03:49:36 +1100 (EST) X-Original-To: linuxppc-dev@ozlabs.org Delivered-To: linuxppc-dev@ozlabs.org Received: from buildserver.ru.mvista.com (unknown [85.21.88.6]) by ozlabs.org (Postfix) with ESMTP id 6F248DDE06 for ; Tue, 7 Oct 2008 03:48:59 +1100 (EST) Received: from localhost (unknown [10.150.0.9]) by buildserver.ru.mvista.com (Postfix) with ESMTP id B548F881D; Mon, 6 Oct 2008 21:48:57 +0500 (SAMST) Date: Mon, 6 Oct 2008 20:48:57 +0400 From: Anton Vorontsov To: Kumar Gala Subject: [PATCH 2/2] powerpc/QE: implement QE Pin Multiplexing API Message-ID: <20081006164857.GB17942@oksana.dev.rtsoft.ru> References: <20081006164802.GA7105@oksana.dev.rtsoft.ru> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20081006164802.GA7105@oksana.dev.rtsoft.ru> User-Agent: Mutt/1.5.18 (2008-05-17) Cc: David Brownell , Timur Tabi , linuxppc-dev@ozlabs.org, Paul Mackerras , David Miller X-BeenThere: linuxppc-dev@ozlabs.org X-Mailman-Version: 2.1.11 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@ozlabs.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@ozlabs.org With this API we're able to set a QE pin to the GPIO mode or a dedicated peripheral function. The API relies on the fact that QE gpio controllers are registered. If they aren't, the API won't work (gracefully though). There is one caveat though: if anybody occupied the node->data before us, or overwrote it, then bad things will happen. Luckily this is all in the platform code that we fully control, so this should never happen. I could implement more checks (for example we could create a list of successfully registered QE controllers, and compare the node->data in the qe_pin_request()), but this is unneeded if nobody is going to do silly things behind our back. Signed-off-by: Anton Vorontsov --- arch/powerpc/include/asm/qe.h | 9 ++ arch/powerpc/sysdev/qe_lib/gpio.c | 195 +++++++++++++++++++++++++++++++++++++ 2 files changed, 204 insertions(+), 0 deletions(-) diff --git a/arch/powerpc/include/asm/qe.h b/arch/powerpc/include/asm/qe.h index edee15d..31ddbc9 100644 --- a/arch/powerpc/include/asm/qe.h +++ b/arch/powerpc/include/asm/qe.h @@ -112,6 +112,15 @@ extern int par_io_config_pin(u8 port, u8 pin, int dir, int open_drain, int assignment, int has_irq); extern int par_io_data_set(u8 port, u8 pin, u8 val); +/* + * Pin multiplexing functions. + */ +struct qe_pin; +extern struct qe_pin *qe_pin_request(struct device_node *np, int index); +extern void qe_pin_free(struct qe_pin *qe_pin); +extern void qe_pin_set_gpio(struct qe_pin *qe_pin); +extern void qe_pin_set_dedicated(struct qe_pin *pin); + /* QE internal API */ int qe_issue_cmd(u32 cmd, u32 device, u8 mcn_protocol, u32 cmd_input); enum qe_clock qe_clock_source(const char *source); diff --git a/arch/powerpc/sysdev/qe_lib/gpio.c b/arch/powerpc/sysdev/qe_lib/gpio.c index 8e5a0bc..7f10b18 100644 --- a/arch/powerpc/sysdev/qe_lib/gpio.c +++ b/arch/powerpc/sysdev/qe_lib/gpio.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include #include @@ -24,8 +25,14 @@ struct qe_gpio_chip { struct of_mm_gpio_chip mm_gc; spinlock_t lock; + unsigned long pin_flags[QE_PIO_PINS]; +#define QE_PIN_REQUESTED 0 + /* shadowed data register to clear/set bits safely */ u32 cpdata; + + /* saved_regs used to restore dedicated functions */ + struct qe_pio_regs saved_regs; }; static inline struct qe_gpio_chip * @@ -40,6 +47,12 @@ static void qe_gpio_save_regs(struct of_mm_gpio_chip *mm_gc) struct qe_pio_regs __iomem *regs = mm_gc->regs; qe_gc->cpdata = in_be32(®s->cpdata); + qe_gc->saved_regs.cpdata = qe_gc->cpdata; + qe_gc->saved_regs.cpdir1 = in_be32(®s->cpdir1); + qe_gc->saved_regs.cpdir2 = in_be32(®s->cpdir2); + qe_gc->saved_regs.cppar1 = in_be32(®s->cppar1); + qe_gc->saved_regs.cppar2 = in_be32(®s->cppar2); + qe_gc->saved_regs.cpodr = in_be32(®s->cpodr); } static int qe_gpio_get(struct gpio_chip *gc, unsigned int gpio) @@ -103,6 +116,188 @@ static int qe_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val) return 0; } +struct qe_pin { + /* + * The qe_gpio_chip name is unfortunate, we should change that to + * something like qe_pio_controller. Someday. + */ + struct qe_gpio_chip *controller; + int num; +}; + +/** + * qe_pin_request - Request a QE pin + * @np: device node to get a pin from + * @index: index of a pin in the device tree + * Context: non-atomic + * + * This function return qe_pin so that you could use it with the rest of + * the QE Pin Multiplexing API. + */ +struct qe_pin *qe_pin_request(struct device_node *np, int index) +{ + struct qe_pin *qe_pin; + struct device_node *gc; + struct of_gpio_chip *of_gc = NULL; + struct of_mm_gpio_chip *mm_gc; + struct qe_gpio_chip *qe_gc; + int err; + int size; + const void *gpio_spec; + const u32 *gpio_cells; + unsigned long flags; + + qe_pin = kzalloc(sizeof(*qe_pin), GFP_KERNEL); + if (!qe_pin) { + pr_debug("%s: can't allocate memory\n", __func__); + return ERR_PTR(-ENOMEM); + } + + err = of_parse_phandles_with_args(np, "gpios", "#gpio-cells", index, + &gc, &gpio_spec); + if (err) { + pr_debug("%s: can't parse gpios property\n", __func__); + goto err0; + } + + if (!of_device_is_compatible(gc, "fsl,mpc8323-qe-pario-bank")) { + pr_debug("%s: tried to get a non-qe pin\n", __func__); + err = -EINVAL; + goto err1; + } + + of_gc = gc->data; + if (!of_gc) { + pr_debug("%s: gpio controller %s isn't registered\n", + np->full_name, gc->full_name); + err = -ENODEV; + goto err1; + } + + gpio_cells = of_get_property(gc, "#gpio-cells", &size); + if (!gpio_cells || size != sizeof(*gpio_cells) || + *gpio_cells != of_gc->gpio_cells) { + pr_debug("%s: wrong #gpio-cells for %s\n", + np->full_name, gc->full_name); + err = -EINVAL; + goto err1; + } + + err = of_gc->xlate(of_gc, np, gpio_spec); + if (err < 0) + goto err1; + + mm_gc = to_of_mm_gpio_chip(&of_gc->gc); + qe_gc = to_qe_gpio_chip(mm_gc); + + spin_lock_irqsave(&qe_gc->lock, flags); + + if (test_and_set_bit(QE_PIN_REQUESTED, &qe_gc->pin_flags[err]) == 0) { + qe_pin->controller = qe_gc; + qe_pin->num = err; + err = 0; + } else { + err = -EBUSY; + } + + spin_unlock_irqrestore(&qe_gc->lock, flags); + + if (!err) + return qe_pin; +err1: + of_node_put(gc); +err0: + kfree(qe_pin); + pr_debug("%s failed with status %d\n", __func__, err); + return ERR_PTR(err); +} +EXPORT_SYMBOL(qe_pin_request); + +/** + * qe_pin_free - Free a pin + * @qe_pin: pointer to the qe_pin structure + * Context: any + * + * This function frees the qe_pin structure and makes a pin available + * for further qe_pin_request() calls. + */ +void qe_pin_free(struct qe_pin *qe_pin) +{ + struct qe_gpio_chip *qe_gc = qe_pin->controller; + unsigned long flags; + const int pin = qe_pin->num; + + spin_lock_irqsave(&qe_gc->lock, flags); + test_and_clear_bit(QE_PIN_REQUESTED, &qe_gc->pin_flags[pin]); + spin_unlock_irqrestore(&qe_gc->lock, flags); + + kfree(qe_pin); +} +EXPORT_SYMBOL(qe_pin_free); + +/** + * qe_pin_set_dedicated - Revert a pin to a dedicated peripheral function mode + * @qe_pin: pointer to the qe_pin structure + * Context: any + * + * This function resets a pin to a dedicated peripheral function that + * has been set up by the firmware. + */ +void qe_pin_set_dedicated(struct qe_pin *qe_pin) +{ + struct qe_gpio_chip *qe_gc = qe_pin->controller; + struct qe_pio_regs __iomem *regs = qe_gc->mm_gc.regs; + struct qe_pio_regs *sregs = &qe_gc->saved_regs; + int pin = qe_pin->num; + u32 mask1 = 1 << (QE_PIO_PINS - (pin + 1)); + u32 mask2 = 0x3 << (QE_PIO_PINS - (pin % (QE_PIO_PINS / 2) + 1) * 2); + bool second_reg = pin > (QE_PIO_PINS / 2) - 1; + unsigned long flags; + + spin_lock_irqsave(&qe_gc->lock, flags); + + if (second_reg) { + clrsetbits_be32(®s->cpdir2, mask2, sregs->cpdir2 & mask2); + clrsetbits_be32(®s->cppar2, mask2, sregs->cppar2 & mask2); + } else { + clrsetbits_be32(®s->cpdir1, mask2, sregs->cpdir1 & mask2); + clrsetbits_be32(®s->cppar1, mask2, sregs->cppar1 & mask2); + } + + if (sregs->cpdata & mask1) + qe_gc->cpdata |= mask1; + else + qe_gc->cpdata &= ~mask1; + + out_be32(®s->cpdata, qe_gc->cpdata); + clrsetbits_be32(®s->cpodr, mask1, sregs->cpodr & mask1); + + spin_unlock_irqrestore(&qe_gc->lock, flags); +} +EXPORT_SYMBOL(qe_pin_set_dedicated); + +/** + * qe_pin_set_gpio - Set a pin to the GPIO mode + * @qe_pin: pointer to the qe_pin structure + * Context: any + * + * This function sets a pin to the GPIO mode. + */ +void qe_pin_set_gpio(struct qe_pin *qe_pin) +{ + struct qe_gpio_chip *qe_gc = qe_pin->controller; + struct qe_pio_regs __iomem *regs = qe_gc->mm_gc.regs; + unsigned long flags; + + spin_lock_irqsave(&qe_gc->lock, flags); + + /* Let's make it input by default, GPIO API is able to change that. */ + __par_io_config_pin(regs, qe_pin->num, QE_PIO_DIR_IN, 0, 0, 0); + + spin_unlock_irqrestore(&qe_gc->lock, flags); +} +EXPORT_SYMBOL(qe_pin_set_gpio); + static int __init qe_add_gpiochips(void) { struct device_node *np;