mfd: Add driver for STA2X11 MFD block

This also introduces <asm/sta2x11.h> to export a function that is in
the base sta2x11 support patches. The header will increase with other
prototypes and constants over time.

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>
Acked-by: Giancarlo Asnaghi <giancarlo.asnaghi@st.com>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 467 insertions, 0 deletions

diff --git a/drivers/mfd/sta2x11-mfd.c b/drivers/mfd/sta2x11-mfd.c
new file mode 100644
index 000000000000..d31fed07aefb
--- /dev/null
+++ b/drivers/mfd/sta2x11-mfd.c
@@ -0,0 +1,467 @@
+/*
+ * Copyright (c) 2009-2011 Wind River Systems, Inc.
+ * Copyright (c) 2011 ST Microelectronics (Alessandro Rubini)
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/errno.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/pci.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/sta2x11-mfd.h>
+
+#include <asm/sta2x11.h>
+
+/* This describes STA2X11 MFD chip for us, we may have several */
+struct sta2x11_mfd {
+        struct sta2x11_instance *instance;
+        spinlock_t lock;
+        struct list_head list;
+        void __iomem *sctl_regs;
+        void __iomem *apbreg_regs;
+};
+
+static LIST_HEAD(sta2x11_mfd_list);
+
+/* Three functions to act on the list */
+static struct sta2x11_mfd *sta2x11_mfd_find(struct pci_dev *pdev)
+{
+        struct sta2x11_instance *instance;
+        struct sta2x11_mfd *mfd;
+
+        if (!pdev && !list_empty(&sta2x11_mfd_list)) {
+                pr_warning("%s: Unspecified device, "
+                            "using first instance\n", __func__);
+                return list_entry(sta2x11_mfd_list.next,
+                                  struct sta2x11_mfd, list);
+        }
+
+        instance = sta2x11_get_instance(pdev);
+        if (!instance)
+                return NULL;
+        list_for_each_entry(mfd, &sta2x11_mfd_list, list) {
+                if (mfd->instance == instance)
+                        return mfd;
+        }
+        return NULL;
+}
+
+static int __devinit sta2x11_mfd_add(struct pci_dev *pdev, gfp_t flags)
+{
+        struct sta2x11_mfd *mfd = sta2x11_mfd_find(pdev);
+        struct sta2x11_instance *instance;
+
+        if (mfd)
+                return -EBUSY;
+        instance = sta2x11_get_instance(pdev);
+        if (!instance)
+                return -EINVAL;
+        mfd = kzalloc(sizeof(*mfd), flags);
+        if (!mfd)
+                return -ENOMEM;
+        INIT_LIST_HEAD(&mfd->list);
+        spin_lock_init(&mfd->lock);
+        mfd->instance = instance;
+        list_add(&mfd->list, &sta2x11_mfd_list);
+        return 0;
+}
+
+static int __devexit mfd_remove(struct pci_dev *pdev)
+{
+        struct sta2x11_mfd *mfd = sta2x11_mfd_find(pdev);
+
+        if (!mfd)
+                return -ENODEV;
+        list_del(&mfd->list);
+        kfree(mfd);
+        return 0;
+}
+
+/* These two functions are exported and are not expected to fail */
+u32 sta2x11_sctl_mask(struct pci_dev *pdev, u32 reg, u32 mask, u32 val)
+{
+        struct sta2x11_mfd *mfd = sta2x11_mfd_find(pdev);
+        u32 r;
+        unsigned long flags;
+
+        if (!mfd) {
+                dev_warn(&pdev->dev, ": can't access sctl regs\n");
+                return 0;
+        }
+        if (!mfd->sctl_regs) {
+                dev_warn(&pdev->dev, ": system ctl not initialized\n");
+                return 0;
+        }
+        spin_lock_irqsave(&mfd->lock, flags);
+        r = readl(mfd->sctl_regs + reg);
+        r &= ~mask;
+        r |= val;
+        if (mask)
+                writel(r, mfd->sctl_regs + reg);
+        spin_unlock_irqrestore(&mfd->lock, flags);
+        return r;
+}
+EXPORT_SYMBOL(sta2x11_sctl_mask);
+
+u32 sta2x11_apbreg_mask(struct pci_dev *pdev, u32 reg, u32 mask, u32 val)
+{
+        struct sta2x11_mfd *mfd = sta2x11_mfd_find(pdev);
+        u32 r;
+        unsigned long flags;
+
+        if (!mfd) {
+                dev_warn(&pdev->dev, ": can't access apb regs\n");
+                return 0;
+        }
+        if (!mfd->apbreg_regs) {
+                dev_warn(&pdev->dev, ": apb bridge not initialized\n");
+                return 0;
+        }
+        spin_lock_irqsave(&mfd->lock, flags);
+        r = readl(mfd->apbreg_regs + reg);
+        r &= ~mask;
+        r |= val;
+        if (mask)
+                writel(r, mfd->apbreg_regs + reg);
+        spin_unlock_irqrestore(&mfd->lock, flags);
+        return r;
+}
+EXPORT_SYMBOL(sta2x11_apbreg_mask);
+
+/* Two debugfs files, for our registers (FIXME: one instance only) */
+#define REG(regname) {.name = #regname, .offset = SCTL_ ## regname}
+static struct debugfs_reg32 sta2x11_sctl_regs[] = {
+        REG(SCCTL), REG(ARMCFG), REG(SCPLLCTL), REG(SCPLLFCTRL),
+        REG(SCRESFRACT), REG(SCRESCTRL1), REG(SCRESXTRL2), REG(SCPEREN0),
+        REG(SCPEREN1), REG(SCPEREN2), REG(SCGRST), REG(SCPCIPMCR1),
+        REG(SCPCIPMCR2), REG(SCPCIPMSR1), REG(SCPCIPMSR2), REG(SCPCIPMSR3),
+        REG(SCINTREN), REG(SCRISR), REG(SCCLKSTAT0), REG(SCCLKSTAT1),
+        REG(SCCLKSTAT2), REG(SCRSTSTA),
+};
+#undef REG
+
+static struct debugfs_regset32 sctl_regset = {
+        .regs = sta2x11_sctl_regs,
+        .nregs = ARRAY_SIZE(sta2x11_sctl_regs),
+};
+
+#define REG(regname) {.name = #regname, .offset = regname}
+static struct debugfs_reg32 sta2x11_apbreg_regs[] = {
+        REG(APBREG_BSR), REG(APBREG_PAER), REG(APBREG_PWAC), REG(APBREG_PRAC),
+        REG(APBREG_PCG), REG(APBREG_PUR), REG(APBREG_EMU_PCG),
+};
+#undef REG
+
+static struct debugfs_regset32 apbreg_regset = {
+        .regs = sta2x11_apbreg_regs,
+        .nregs = ARRAY_SIZE(sta2x11_apbreg_regs),
+};
+
+static struct dentry *sta2x11_sctl_debugfs;
+static struct dentry *sta2x11_apbreg_debugfs;
+
+/* Probe for the two platform devices */
+static int sta2x11_sctl_probe(struct platform_device *dev)
+{
+        struct pci_dev **pdev;
+        struct sta2x11_mfd *mfd;
+        struct resource *res;
+
+        pdev = dev->dev.platform_data;
+        mfd = sta2x11_mfd_find(*pdev);
+        if (!mfd)
+                return -ENODEV;
+
+        res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+        if (!res)
+                return -ENOMEM;
+
+        if (!request_mem_region(res->start, resource_size(res),
+                                "sta2x11-sctl"))
+                return -EBUSY;
+
+        mfd->sctl_regs = ioremap(res->start, resource_size(res));
+        if (!mfd->sctl_regs) {
+                release_mem_region(res->start, resource_size(res));
+                return -ENOMEM;
+        }
+        sctl_regset.base = mfd->sctl_regs;
+        sta2x11_sctl_debugfs = debugfs_create_regset32("sta2x11-sctl",
+                                                  S_IFREG | S_IRUGO,
+                                                  NULL, &sctl_regset);
+        return 0;
+}
+
+static int sta2x11_apbreg_probe(struct platform_device *dev)
+{
+        struct pci_dev **pdev;
+        struct sta2x11_mfd *mfd;
+        struct resource *res;
+
+        pdev = dev->dev.platform_data;
+        dev_dbg(&dev->dev, "%s: pdata is %p\n", __func__, pdev);
+        dev_dbg(&dev->dev, "%s: *pdata is %p\n", __func__, *pdev);
+
+        mfd = sta2x11_mfd_find(*pdev);
+        if (!mfd)
+                return -ENODEV;
+
+        res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+        if (!res)
+                return -ENOMEM;
+
+        if (!request_mem_region(res->start, resource_size(res),
+                                "sta2x11-apbreg"))
+                return -EBUSY;
+
+        mfd->apbreg_regs = ioremap(res->start, resource_size(res));
+        if (!mfd->apbreg_regs) {
+                release_mem_region(res->start, resource_size(res));
+                return -ENOMEM;
+        }
+        dev_dbg(&dev->dev, "%s: regbase %p\n", __func__, mfd->apbreg_regs);
+
+        apbreg_regset.base = mfd->apbreg_regs;
+        sta2x11_apbreg_debugfs = debugfs_create_regset32("sta2x11-apbreg",
+                                                  S_IFREG | S_IRUGO,
+                                                  NULL, &apbreg_regset);
+        return 0;
+}
+
+/* The two platform drivers */
+static struct platform_driver sta2x11_sctl_platform_driver = {
+        .driver = {
+                .name   = "sta2x11-sctl",
+                .owner  = THIS_MODULE,
+        },
+        .probe          = sta2x11_sctl_probe,
+};
+
+static int __init sta2x11_sctl_init(void)
+{
+        pr_info("%s\n", __func__);
+        return platform_driver_register(&sta2x11_sctl_platform_driver);
+}
+
+static struct platform_driver sta2x11_platform_driver = {
+        .driver = {
+                .name   = "sta2x11-apbreg",
+                .owner  = THIS_MODULE,
+        },
+        .probe          = sta2x11_apbreg_probe,
+};
+
+static int __init sta2x11_apbreg_init(void)
+{
+        pr_info("%s\n", __func__);
+        return platform_driver_register(&sta2x11_platform_driver);
+}
+
+/*
+ * What follows is the PCI device that hosts the above two pdevs.
+ * Each logic block is 4kB and they are all consecutive: we use this info.
+ */
+
+/* Bar 0 */
+enum bar0_cells {
+        STA2X11_GPIO_0 = 0,
+        STA2X11_GPIO_1,
+        STA2X11_GPIO_2,
+        STA2X11_GPIO_3,
+        STA2X11_SCTL,
+        STA2X11_SCR,
+        STA2X11_TIME,
+};
+/* Bar 1 */
+enum bar1_cells {
+        STA2X11_APBREG = 0,
+};
+#define CELL_4K(_name, _cell) { \
+                .name = _name, \
+                .start = _cell * 4096, .end = _cell * 4096 + 4095, \
+                .flags = IORESOURCE_MEM, \
+                }
+
+static const __devinitconst struct resource gpio_resources[] = {
+        {
+                .name = "sta2x11_gpio", /* 4 consecutive cells, 1 driver */
+                .start = 0,
+                .end = (4 * 4096) - 1,
+                .flags = IORESOURCE_MEM,
+        }
+};
+static const __devinitconst struct resource sctl_resources[] = {
+        CELL_4K("sta2x11-sctl", STA2X11_SCTL),
+};
+static const __devinitconst struct resource scr_resources[] = {
+        CELL_4K("sta2x11-scr", STA2X11_SCR),
+};
+static const __devinitconst struct resource time_resources[] = {
+        CELL_4K("sta2x11-time", STA2X11_TIME),
+};
+
+static const __devinitconst struct resource apbreg_resources[] = {
+        CELL_4K("sta2x11-apbreg", STA2X11_APBREG),
+};
+
+#define DEV(_name, _r) \
+        { .name = _name, .num_resources = ARRAY_SIZE(_r), .resources = _r, }
+
+static __devinitdata struct mfd_cell sta2x11_mfd_bar0[] = {
+        DEV("sta2x11-gpio", gpio_resources), /* offset 0: we add pdata later */
+        DEV("sta2x11-sctl", sctl_resources),
+        DEV("sta2x11-scr", scr_resources),
+        DEV("sta2x11-time", time_resources),
+};
+
+static __devinitdata struct mfd_cell sta2x11_mfd_bar1[] = {
+        DEV("sta2x11-apbreg", apbreg_resources),
+};
+
+static int sta2x11_mfd_suspend(struct pci_dev *pdev, pm_message_t state)
+{
+        pci_save_state(pdev);
+        pci_disable_device(pdev);
+        pci_set_power_state(pdev, pci_choose_state(pdev, state));
+
+        return 0;
+}
+
+static int sta2x11_mfd_resume(struct pci_dev *pdev)
+{
+        int err;
+
+        pci_set_power_state(pdev, 0);
+        err = pci_enable_device(pdev);
+        if (err)
+                return err;
+        pci_restore_state(pdev);
+
+        return 0;
+}
+
+static int __devinit sta2x11_mfd_probe(struct pci_dev *pdev,
+                                       const struct pci_device_id *pci_id)
+{
+        int err, i;
+        struct sta2x11_gpio_pdata *gpio_data;
+
+        dev_info(&pdev->dev, "%s\n", __func__);
+
+        err = pci_enable_device(pdev);
+        if (err) {
+                dev_err(&pdev->dev, "Can't enable device.\n");
+                return err;
+        }
+
+        err = pci_enable_msi(pdev);
+        if (err)
+                dev_info(&pdev->dev, "Enable msi failed\n");
+
+        /* Read gpio config data as pci device's platform data */
+        gpio_data = dev_get_platdata(&pdev->dev);
+        if (!gpio_data)
+                dev_warn(&pdev->dev, "no gpio configuration\n");
+
+        dev_dbg(&pdev->dev, "%s, gpio_data = %p (%p)\n", __func__,
+                gpio_data, &gpio_data);
+        dev_dbg(&pdev->dev, "%s, pdev = %p (%p)\n", __func__,
+                pdev, &pdev);
+
+        /* platform data is the pci device for all of them */
+        for (i = 0; i < ARRAY_SIZE(sta2x11_mfd_bar0); i++) {
+                sta2x11_mfd_bar0[i].pdata_size = sizeof(pdev);
+                sta2x11_mfd_bar0[i].platform_data = &pdev;
+        }
+        sta2x11_mfd_bar1[0].pdata_size = sizeof(pdev);
+        sta2x11_mfd_bar1[0].platform_data = &pdev;
+
+        /* Record this pdev before mfd_add_devices: their probe looks for it */
+        sta2x11_mfd_add(pdev, GFP_ATOMIC);
+
+
+        err = mfd_add_devices(&pdev->dev, -1,
+                              sta2x11_mfd_bar0,
+                              ARRAY_SIZE(sta2x11_mfd_bar0),
+                              &pdev->resource[0],
+                              0);
+        if (err) {
+                dev_err(&pdev->dev, "mfd_add_devices[0] failed: %d\n", err);
+                goto err_disable;
+        }
+
+        err = mfd_add_devices(&pdev->dev, -1,
+                              sta2x11_mfd_bar1,
+                              ARRAY_SIZE(sta2x11_mfd_bar1),
+                              &pdev->resource[1],
+                              0);
+        if (err) {
+                dev_err(&pdev->dev, "mfd_add_devices[1] failed: %d\n", err);
+                goto err_disable;
+        }
+
+        return 0;
+
+err_disable:
+        mfd_remove_devices(&pdev->dev);
+        pci_disable_device(pdev);
+        pci_disable_msi(pdev);
+        return err;
+}
+
+static DEFINE_PCI_DEVICE_TABLE(sta2x11_mfd_tbl) = {
+        {PCI_DEVICE(PCI_VENDOR_ID_STMICRO, PCI_DEVICE_ID_STMICRO_GPIO)},
+        {0,},
+};
+
+static struct pci_driver sta2x11_mfd_driver = {
+        .name =         "sta2x11-mfd",
+        .id_table =     sta2x11_mfd_tbl,
+        .probe =        sta2x11_mfd_probe,
+        .suspend =      sta2x11_mfd_suspend,
+        .resume =       sta2x11_mfd_resume,
+};
+
+static int __init sta2x11_mfd_init(void)
+{
+        pr_info("%s\n", __func__);
+        return pci_register_driver(&sta2x11_mfd_driver);
+}
+
+/*
+ * All of this must be ready before "normal" devices like MMCI appear.
+ * But MFD (the pci device) can't be too early. The following choice
+ * prepares platform drivers very early and probe the PCI device later,
+ * but before other PCI devices.
+ */
+subsys_initcall(sta2x11_apbreg_init);
+subsys_initcall(sta2x11_sctl_init);
+rootfs_initcall(sta2x11_mfd_init);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Wind River");
+MODULE_DESCRIPTION("STA2x11 mfd for GPIO, SCTL and APBREG");
+MODULE_DEVICE_TABLE(pci, sta2x11_mfd_tbl);