irqchip: st: Supply new driver for STi based devices

This driver is used to enable System Configuration Register controlled
External, CTI (Core Sight), PMU (Performance Management), and PL310 L2
Cache IRQs prior to use.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lkml.kernel.org/r/1424272444-16230-3-git-send-email-lee.jones@linaro.org
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

3 files changed, 214 insertions, 0 deletions

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index cc79d2a5a8c2..c8d260e33a90 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -110,6 +110,13 @@ config RENESAS_IRQC
         bool
         select IRQ_DOMAIN
 
+config ST_IRQCHIP
+        bool
+        select REGMAP
+        select MFD_SYSCON
+        help
+          Enables SysCfg Controlled IRQs on STi based platforms.
+
 config TB10X_IRQC
         bool
         select IRQ_DOMAIN
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 42965d2476bb..9bb4fd191e94 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -33,6 +33,7 @@ obj-$(CONFIG_RENESAS_IRQC)		+= irq-renesas-irqc.o
 obj-$(CONFIG_VERSATILE_FPGA_IRQ)        += irq-versatile-fpga.o
 obj-$(CONFIG_ARCH_NSPIRE)               += irq-zevio.o
 obj-$(CONFIG_ARCH_VT8500)               += irq-vt8500.o
+obj-$(CONFIG_ST_IRQCHIP)                += irq-st.o
 obj-$(CONFIG_TB10X_IRQC)                += irq-tb10x.o
 obj-$(CONFIG_XTENSA)                    += irq-xtensa-pic.o
 obj-$(CONFIG_XTENSA_MX)                 += irq-xtensa-mx.o
diff --git a/drivers/irqchip/irq-st.c b/drivers/irqchip/irq-st.c
new file mode 100644
index 000000000000..9af48a85c16f
--- /dev/null
+++ b/drivers/irqchip/irq-st.c
@@ -0,0 +1,206 @@
+/*
+ *  Copyright (C) 2014 STMicroelectronics – All Rights Reserved
+ *
+ *  Author: Lee Jones <lee.jones@linaro.org>
+ *
+ *  This is a re-write of Christophe Kerello's PMU driver.
+ *
+ * This program 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.
+ */
+
+#include <dt-bindings/interrupt-controller/irq-st.h>
+#include <linux/err.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#define STIH415_SYSCFG_642              0x0a8
+#define STIH416_SYSCFG_7543             0x87c
+#define STIH407_SYSCFG_5102             0x198
+#define STID127_SYSCFG_734              0x088
+
+#define ST_A9_IRQ_MASK                  0x001FFFFF
+#define ST_A9_IRQ_MAX_CHANS             2
+
+#define ST_A9_IRQ_EN_CTI_0              BIT(0)
+#define ST_A9_IRQ_EN_CTI_1              BIT(1)
+#define ST_A9_IRQ_EN_PMU_0              BIT(2)
+#define ST_A9_IRQ_EN_PMU_1              BIT(3)
+#define ST_A9_IRQ_EN_PL310_L2           BIT(4)
+#define ST_A9_IRQ_EN_EXT_0              BIT(5)
+#define ST_A9_IRQ_EN_EXT_1              BIT(6)
+#define ST_A9_IRQ_EN_EXT_2              BIT(7)
+
+#define ST_A9_FIQ_N_SEL(dev, chan)      (dev << (8  + (chan * 3)))
+#define ST_A9_IRQ_N_SEL(dev, chan)      (dev << (14 + (chan * 3)))
+#define ST_A9_EXTIRQ_INV_SEL(dev)       (dev << 20)
+
+struct st_irq_syscfg {
+        struct regmap *regmap;
+        unsigned int syscfg;
+        unsigned int config;
+        bool ext_inverted;
+};
+
+static const struct of_device_id st_irq_syscfg_match[] = {
+        {
+                .compatible = "st,stih415-irq-syscfg",
+                .data = (void *)STIH415_SYSCFG_642,
+        },
+        {
+                .compatible = "st,stih416-irq-syscfg",
+                .data = (void *)STIH416_SYSCFG_7543,
+        },
+        {
+                .compatible = "st,stih407-irq-syscfg",
+                .data = (void *)STIH407_SYSCFG_5102,
+        },
+        {
+                .compatible = "st,stid127-irq-syscfg",
+                .data = (void *)STID127_SYSCFG_734,
+        },
+        {}
+};
+
+static int st_irq_xlate(struct platform_device *pdev,
+                        int device, int channel, bool irq)
+{
+        struct st_irq_syscfg *ddata = dev_get_drvdata(&pdev->dev);
+
+        /* Set the device enable bit. */
+        switch (device) {
+        case ST_IRQ_SYSCFG_EXT_0:
+                ddata->config |= ST_A9_IRQ_EN_EXT_0;
+                break;
+        case ST_IRQ_SYSCFG_EXT_1:
+                ddata->config |= ST_A9_IRQ_EN_EXT_1;
+                break;
+        case ST_IRQ_SYSCFG_EXT_2:
+                ddata->config |= ST_A9_IRQ_EN_EXT_2;
+                break;
+        case ST_IRQ_SYSCFG_CTI_0:
+                ddata->config |= ST_A9_IRQ_EN_CTI_0;
+                break;
+        case ST_IRQ_SYSCFG_CTI_1:
+                ddata->config |= ST_A9_IRQ_EN_CTI_1;
+                break;
+        case ST_IRQ_SYSCFG_PMU_0:
+                ddata->config |= ST_A9_IRQ_EN_PMU_0;
+                break;
+        case ST_IRQ_SYSCFG_PMU_1:
+                ddata->config |= ST_A9_IRQ_EN_PMU_1;
+                break;
+        case ST_IRQ_SYSCFG_pl310_L2:
+                ddata->config |= ST_A9_IRQ_EN_PL310_L2;
+                break;
+        case ST_IRQ_SYSCFG_DISABLED:
+                return 0;
+        default:
+                dev_err(&pdev->dev, "Unrecognised device %d\n", device);
+                return -EINVAL;
+        }
+
+        /* Select IRQ/FIQ channel for device. */
+        ddata->config |= irq ?
+                ST_A9_IRQ_N_SEL(device, channel) :
+                ST_A9_FIQ_N_SEL(device, channel);
+
+        return 0;
+}
+
+static int st_irq_syscfg_enable(struct platform_device *pdev)
+{
+        struct device_node *np = pdev->dev.of_node;
+        struct st_irq_syscfg *ddata = dev_get_drvdata(&pdev->dev);
+        int channels, ret, i;
+        u32 device, invert;
+
+        channels = of_property_count_u32_elems(np, "st,irq-device");
+        if (channels != ST_A9_IRQ_MAX_CHANS) {
+                dev_err(&pdev->dev, "st,enable-irq-device must have 2 elems\n");
+                return -EINVAL;
+        }
+
+        channels = of_property_count_u32_elems(np, "st,fiq-device");
+        if (channels != ST_A9_IRQ_MAX_CHANS) {
+                dev_err(&pdev->dev, "st,enable-fiq-device must have 2 elems\n");
+                return -EINVAL;
+        }
+
+        for (i = 0; i < ST_A9_IRQ_MAX_CHANS; i++) {
+                of_property_read_u32_index(np, "st,irq-device", i, &device);
+
+                ret = st_irq_xlate(pdev, device, i, true);
+                if (ret)
+                        return ret;
+
+                of_property_read_u32_index(np, "st,fiq-device", i, &device);
+
+                ret = st_irq_xlate(pdev, device, i, false);
+                if (ret)
+                        return ret;
+        }
+
+        /* External IRQs may be inverted. */
+        of_property_read_u32(np, "st,invert-ext", &invert);
+        ddata->config |= ST_A9_EXTIRQ_INV_SEL(invert);
+
+        return regmap_update_bits(ddata->regmap, ddata->syscfg,
+                                  ST_A9_IRQ_MASK, ddata->config);
+}
+
+static int st_irq_syscfg_probe(struct platform_device *pdev)
+{
+        struct device_node *np = pdev->dev.of_node;
+        const struct of_device_id *match;
+        struct st_irq_syscfg *ddata;
+
+        ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
+        if (!ddata)
+                return -ENOMEM;
+
+        match = of_match_device(st_irq_syscfg_match, &pdev->dev);
+        if (!match)
+                return -ENODEV;
+
+        ddata->syscfg = (unsigned int)match->data;
+
+        ddata->regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg");
+        if (IS_ERR(ddata->regmap)) {
+                dev_err(&pdev->dev, "syscfg phandle missing\n");
+                return PTR_ERR(ddata->regmap);
+        }
+
+        dev_set_drvdata(&pdev->dev, ddata);
+
+        return st_irq_syscfg_enable(pdev);
+}
+
+static int st_irq_syscfg_resume(struct device *dev)
+{
+        struct st_irq_syscfg *ddata = dev_get_drvdata(dev);
+
+        return regmap_update_bits(ddata->regmap, ddata->syscfg,
+                                  ST_A9_IRQ_MASK, ddata->config);
+}
+
+static SIMPLE_DEV_PM_OPS(st_irq_syscfg_pm_ops, NULL, st_irq_syscfg_resume);
+
+static struct platform_driver st_irq_syscfg_driver = {
+        .driver = {
+                .name = "st_irq_syscfg",
+                .pm = &st_irq_syscfg_pm_ops,
+                .of_match_table = st_irq_syscfg_match,
+        },
+        .probe = st_irq_syscfg_probe,
+};
+
+static int __init st_irq_syscfg_init(void)
+{
+        return platform_driver_register(&st_irq_syscfg_driver);
+}
+core_initcall(st_irq_syscfg_init);