diff options
author | viresh kumar <viresh.kumar@st.com> | 2010-05-03 09:24:30 +0100 |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2010-05-04 16:54:54 +0100 |
commit | 4c18e77f718cdda33363132127db4df795eadbd9 (patch) | |
tree | bbecdc08f487246049bb6d0c212d338a9056597a /arch/arm/plat-spear/shirq.c | |
parent | ff37f6e5910c4fd7ad42063d89c0687def665941 (diff) | |
download | op-kernel-dev-4c18e77f718cdda33363132127db4df795eadbd9.zip op-kernel-dev-4c18e77f718cdda33363132127db4df795eadbd9.tar.gz |
ARM: 6091/1: ST SPEAr: Adding support for shared irq layer
Multiple peripherals in SPEAr share common hardware interrupt lines.
This patch adds support for a shared irq layer, which registers hardware
irqs by itself and exposes virtual irq numbers to peripherals.
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/plat-spear/shirq.c')
-rw-r--r-- | arch/arm/plat-spear/shirq.c | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/arch/arm/plat-spear/shirq.c b/arch/arm/plat-spear/shirq.c new file mode 100644 index 0000000..2172d69 --- /dev/null +++ b/arch/arm/plat-spear/shirq.c @@ -0,0 +1,118 @@ +/* + * arch/arm/plat-spear/shirq.c + * + * SPEAr platform shared irq layer source file + * + * Copyright (C) 2009 ST Microelectronics + * Viresh Kumar<viresh.kumar@st.com> + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include <linux/err.h> +#include <linux/io.h> +#include <linux/irq.h> +#include <linux/spinlock.h> +#include <plat/shirq.h> + +struct spear_shirq *shirq; +static DEFINE_SPINLOCK(lock); + +static void shirq_irq_mask(unsigned irq) +{ + struct spear_shirq *shirq = get_irq_chip_data(irq); + u32 val, id = irq - shirq->dev_config[0].virq; + unsigned long flags; + + if ((shirq->regs.enb_reg == -1) || shirq->dev_config[id].enb_mask == -1) + return; + + spin_lock_irqsave(&lock, flags); + val = readl(shirq->regs.base + shirq->regs.enb_reg); + if (shirq->regs.reset_to_enb) + val |= shirq->dev_config[id].enb_mask; + else + val &= ~(shirq->dev_config[id].enb_mask); + writel(val, shirq->regs.base + shirq->regs.enb_reg); + spin_unlock_irqrestore(&lock, flags); +} + +static void shirq_irq_unmask(unsigned irq) +{ + struct spear_shirq *shirq = get_irq_chip_data(irq); + u32 val, id = irq - shirq->dev_config[0].virq; + unsigned long flags; + + if ((shirq->regs.enb_reg == -1) || shirq->dev_config[id].enb_mask == -1) + return; + + spin_lock_irqsave(&lock, flags); + val = readl(shirq->regs.base + shirq->regs.enb_reg); + if (shirq->regs.reset_to_enb) + val &= ~(shirq->dev_config[id].enb_mask); + else + val |= shirq->dev_config[id].enb_mask; + writel(val, shirq->regs.base + shirq->regs.enb_reg); + spin_unlock_irqrestore(&lock, flags); +} + +static struct irq_chip shirq_chip = { + .name = "spear_shirq", + .ack = shirq_irq_mask, + .mask = shirq_irq_mask, + .unmask = shirq_irq_unmask, +}; + +static void shirq_handler(unsigned irq, struct irq_desc *desc) +{ + u32 i, val, mask; + struct spear_shirq *shirq = get_irq_data(irq); + + desc->chip->ack(irq); + while ((val = readl(shirq->regs.base + shirq->regs.status_reg) & + shirq->regs.status_reg_mask)) { + for (i = 0; (i < shirq->dev_count) && val; i++) { + if (!(shirq->dev_config[i].status_mask & val)) + continue; + + generic_handle_irq(shirq->dev_config[i].virq); + + /* clear interrupt */ + val &= ~shirq->dev_config[i].status_mask; + if ((shirq->regs.clear_reg == -1) || + shirq->dev_config[i].clear_mask == -1) + continue; + mask = readl(shirq->regs.base + shirq->regs.clear_reg); + if (shirq->regs.reset_to_clear) + mask &= ~shirq->dev_config[i].clear_mask; + else + mask |= shirq->dev_config[i].clear_mask; + writel(mask, shirq->regs.base + shirq->regs.clear_reg); + } + } + desc->chip->unmask(irq); +} + +int spear_shirq_register(struct spear_shirq *shirq) +{ + int i; + + if (!shirq || !shirq->dev_config || !shirq->regs.base) + return -EFAULT; + + if (!shirq->dev_count) + return -EINVAL; + + set_irq_chained_handler(shirq->irq, shirq_handler); + for (i = 0; i < shirq->dev_count; i++) { + set_irq_chip(shirq->dev_config[i].virq, &shirq_chip); + set_irq_handler(shirq->dev_config[i].virq, handle_simple_irq); + set_irq_flags(shirq->dev_config[i].virq, IRQF_VALID); + set_irq_chip_data(shirq->dev_config[i].virq, shirq); + } + + set_irq_data(shirq->irq, shirq); + return 0; +} |