mfd: intel_quark_i2c_gpio: Add Intel Quark X1000 I2C-GPIO MFD Driver

In Quark X1000, there's a single PCI device that provides both
an I2C controller and a GPIO controller. This MFD driver will
split the 2 devices for their respective drivers.

This patch is based on Josef Ahmad's initial work for Quark enabling.

Acked-by: Michael Turquette <mturquette@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Weike Chen <alvin.chen@intel.com>
Signed-off-by: Raymond Tan <raymond.tan@intel.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

3 files changed, 290 insertions, 0 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index f49f404c2004..b277f37ae3be 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -283,6 +283,18 @@ config HTC_I2CPLD
           This device provides input and output GPIOs through an I2C
           interface to one or more sub-chips.
 
+config MFD_INTEL_QUARK_I2C_GPIO
+        tristate "Intel Quark MFD I2C GPIO"
+        depends on PCI
+        depends on X86
+        depends on COMMON_CLK
+        select MFD_CORE
+        help
+          This MFD provides support for I2C and GPIO that exist only
+          in a single PCI device. It splits the 2 IO devices to
+          their respective IO driver.
+          The GPIO exports a total amount of 8 interrupt-capable GPIOs.
+
 config LPC_ICH
         tristate "Intel ICH LPC"
         depends on PCI
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 234998d77d43..5ebe443b595a 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -139,6 +139,7 @@ obj-$(CONFIG_AB8500_CORE)	+= ab8500-core.o ab8500-sysctrl.o
 obj-$(CONFIG_MFD_TIMBERDALE)    += timberdale.o
 obj-$(CONFIG_PMIC_ADP5520)      += adp5520.o
 obj-$(CONFIG_MFD_KEMPLD)        += kempld-core.o
+obj-$(CONFIG_MFD_INTEL_QUARK_I2C_GPIO)  += intel_quark_i2c_gpio.o
 obj-$(CONFIG_LPC_SCH)           += lpc_sch.o
 obj-$(CONFIG_LPC_ICH)           += lpc_ich.o
 obj-$(CONFIG_MFD_RDC321X)       += rdc321x-southbridge.o
diff --git a/drivers/mfd/intel_quark_i2c_gpio.c b/drivers/mfd/intel_quark_i2c_gpio.c
new file mode 100644
index 000000000000..006f2a1b1b1e
--- /dev/null
+++ b/drivers/mfd/intel_quark_i2c_gpio.c
@@ -0,0 +1,277 @@
+/*
+ * Intel Quark MFD PCI driver for I2C & GPIO
+ *
+ * Copyright(c) 2014 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.
+ *
+ * Intel Quark PCI device for I2C and GPIO controller sharing the same
+ * PCI function. This PCI driver will split the 2 devices into their
+ * respective drivers.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/mfd/core.h>
+#include <linux/clkdev.h>
+#include <linux/clk-provider.h>
+#include <linux/dmi.h>
+#include <linux/platform_data/gpio-dwapb.h>
+#include <linux/platform_data/i2c-designware.h>
+
+/* PCI BAR for register base address */
+#define MFD_I2C_BAR             0
+#define MFD_GPIO_BAR            1
+
+/* The base GPIO number under GPIOLIB framework */
+#define INTEL_QUARK_MFD_GPIO_BASE       8
+
+/* The default number of South-Cluster GPIO on Quark. */
+#define INTEL_QUARK_MFD_NGPIO           8
+
+/* The DesignWare GPIO ports on Quark. */
+#define INTEL_QUARK_GPIO_NPORTS 1
+
+#define INTEL_QUARK_IORES_MEM   0
+#define INTEL_QUARK_IORES_IRQ   1
+
+#define INTEL_QUARK_I2C_CONTROLLER_CLK "i2c_designware.0"
+
+/* The Quark I2C controller source clock */
+#define INTEL_QUARK_I2C_CLK_HZ  33000000
+
+#define INTEL_QUARK_I2C_NCLK    1
+
+struct intel_quark_mfd {
+        struct pci_dev          *pdev;
+        struct clk              *i2c_clk;
+        struct clk_lookup       *i2c_clk_lookup;
+};
+
+struct i2c_mode_info {
+        const char *name;
+        unsigned int i2c_scl_freq;
+};
+
+static const struct i2c_mode_info platform_i2c_mode_info[] = {
+        {
+                .name = "Galileo",
+                .i2c_scl_freq = 100000,
+        },
+        {
+                .name = "GalileoGen2",
+                .i2c_scl_freq = 400000,
+        },
+};
+
+static struct resource intel_quark_i2c_res[] = {
+        [INTEL_QUARK_IORES_MEM] = {
+                .flags = IORESOURCE_MEM,
+        },
+        [INTEL_QUARK_IORES_IRQ] = {
+                .flags = IORESOURCE_IRQ,
+        },
+};
+
+static struct resource intel_quark_gpio_res[] = {
+        [INTEL_QUARK_IORES_MEM] = {
+                .flags = IORESOURCE_MEM,
+        },
+};
+
+static struct mfd_cell intel_quark_mfd_cells[] = {
+        {
+                .id = MFD_I2C_BAR,
+                .name = "i2c_designware",
+                .num_resources = ARRAY_SIZE(intel_quark_i2c_res),
+                .resources = intel_quark_i2c_res,
+                .ignore_resource_conflicts = true,
+        },
+        {
+                .id = MFD_GPIO_BAR,
+                .name = "gpio-dwapb",
+                .num_resources = ARRAY_SIZE(intel_quark_gpio_res),
+                .resources = intel_quark_gpio_res,
+                .ignore_resource_conflicts = true,
+        },
+};
+
+static const struct pci_device_id intel_quark_mfd_ids[] = {
+        { PCI_VDEVICE(INTEL, 0x0934), },
+        {},
+};
+MODULE_DEVICE_TABLE(pci, intel_quark_mfd_ids);
+
+static int intel_quark_register_i2c_clk(struct intel_quark_mfd *quark_mfd)
+{
+        struct pci_dev *pdev = quark_mfd->pdev;
+        struct clk_lookup *i2c_clk_lookup;
+        struct clk *i2c_clk;
+        int ret;
+
+        i2c_clk_lookup = devm_kcalloc(&pdev->dev, INTEL_QUARK_I2C_NCLK,
+                                      sizeof(*i2c_clk_lookup), GFP_KERNEL);
+        if (!i2c_clk_lookup)
+                return -ENOMEM;
+
+        i2c_clk_lookup[0].dev_id = INTEL_QUARK_I2C_CONTROLLER_CLK;
+
+        i2c_clk = clk_register_fixed_rate(&pdev->dev,
+                                          INTEL_QUARK_I2C_CONTROLLER_CLK, NULL,
+                                          CLK_IS_ROOT, INTEL_QUARK_I2C_CLK_HZ);
+
+        quark_mfd->i2c_clk_lookup = i2c_clk_lookup;
+        quark_mfd->i2c_clk = i2c_clk;
+
+        ret = clk_register_clkdevs(i2c_clk, i2c_clk_lookup,
+                                   INTEL_QUARK_I2C_NCLK);
+        if (ret)
+                dev_err(&pdev->dev, "Fixed clk register failed: %d\n", ret);
+
+        return ret;
+}
+
+static void intel_quark_unregister_i2c_clk(struct pci_dev *pdev)
+{
+        struct intel_quark_mfd *quark_mfd = dev_get_drvdata(&pdev->dev);
+
+        if (!quark_mfd->i2c_clk || !quark_mfd->i2c_clk_lookup)
+                return;
+
+        clkdev_drop(quark_mfd->i2c_clk_lookup);
+        clk_unregister(quark_mfd->i2c_clk);
+}
+
+static int intel_quark_i2c_setup(struct pci_dev *pdev, struct mfd_cell *cell)
+{
+        const char *board_name = dmi_get_system_info(DMI_BOARD_NAME);
+        struct dw_i2c_platform_data *pdata;
+        struct resource *res = (struct resource *)cell->resources;
+        struct device *dev = &pdev->dev;
+        unsigned int i;
+
+        res[INTEL_QUARK_IORES_MEM].start =
+                pci_resource_start(pdev, MFD_I2C_BAR);
+        res[INTEL_QUARK_IORES_MEM].end =
+                pci_resource_end(pdev, MFD_I2C_BAR);
+
+        res[INTEL_QUARK_IORES_IRQ].start = pdev->irq;
+        res[INTEL_QUARK_IORES_IRQ].end = pdev->irq;
+
+        pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+        if (!pdata)
+                return -ENOMEM;
+
+        /* Fast mode by default */
+        pdata->i2c_scl_freq = 400000;
+
+        for (i = 0; i < ARRAY_SIZE(platform_i2c_mode_info); i++)
+                if (!strcmp(board_name, platform_i2c_mode_info[i].name))
+                        pdata->i2c_scl_freq
+                                = platform_i2c_mode_info[i].i2c_scl_freq;
+
+        cell->platform_data = pdata;
+        cell->pdata_size = sizeof(*pdata);
+
+        return 0;
+}
+
+static int intel_quark_gpio_setup(struct pci_dev *pdev, struct mfd_cell *cell)
+{
+        struct dwapb_platform_data *pdata;
+        struct resource *res = (struct resource *)cell->resources;
+        struct device *dev = &pdev->dev;
+
+        res[INTEL_QUARK_IORES_MEM].start =
+                pci_resource_start(pdev, MFD_GPIO_BAR);
+        res[INTEL_QUARK_IORES_MEM].end =
+                pci_resource_end(pdev, MFD_GPIO_BAR);
+
+        pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+        if (!pdata)
+                return -ENOMEM;
+
+        /* For intel quark x1000, it has only one port: portA */
+        pdata->nports = INTEL_QUARK_GPIO_NPORTS;
+        pdata->properties = devm_kcalloc(dev, pdata->nports,
+                                         sizeof(*pdata->properties),
+                                         GFP_KERNEL);
+        if (!pdata->properties)
+                return -ENOMEM;
+
+        /* Set the properties for portA */
+        pdata->properties->node         = NULL;
+        pdata->properties->name         = "intel-quark-x1000-gpio-portA";
+        pdata->properties->idx          = 0;
+        pdata->properties->ngpio        = INTEL_QUARK_MFD_NGPIO;
+        pdata->properties->gpio_base    = INTEL_QUARK_MFD_GPIO_BASE;
+        pdata->properties->irq          = pdev->irq;
+        pdata->properties->irq_shared   = true;
+
+        cell->platform_data = pdata;
+        cell->pdata_size = sizeof(*pdata);
+
+        return 0;
+}
+
+static int intel_quark_mfd_probe(struct pci_dev *pdev,
+                                 const struct pci_device_id *id)
+{
+        struct intel_quark_mfd *quark_mfd;
+        int ret;
+
+        ret = pcim_enable_device(pdev);
+        if (ret)
+                return ret;
+
+        quark_mfd = devm_kzalloc(&pdev->dev, sizeof(*quark_mfd), GFP_KERNEL);
+        if (!quark_mfd)
+                return -ENOMEM;
+        quark_mfd->pdev = pdev;
+
+        ret = intel_quark_register_i2c_clk(quark_mfd);
+        if (ret)
+                return ret;
+
+        dev_set_drvdata(&pdev->dev, quark_mfd);
+
+        ret = intel_quark_i2c_setup(pdev, &intel_quark_mfd_cells[MFD_I2C_BAR]);
+        if (ret)
+                return ret;
+
+        ret = intel_quark_gpio_setup(pdev,
+                                     &intel_quark_mfd_cells[MFD_GPIO_BAR]);
+        if (ret)
+                return ret;
+
+        return mfd_add_devices(&pdev->dev, 0, intel_quark_mfd_cells,
+                               ARRAY_SIZE(intel_quark_mfd_cells), NULL, 0,
+                               NULL);
+}
+
+static void intel_quark_mfd_remove(struct pci_dev *pdev)
+{
+        intel_quark_unregister_i2c_clk(pdev);
+        mfd_remove_devices(&pdev->dev);
+}
+
+static struct pci_driver intel_quark_mfd_driver = {
+        .name           = "intel_quark_mfd_i2c_gpio",
+        .id_table       = intel_quark_mfd_ids,
+        .probe          = intel_quark_mfd_probe,
+        .remove         = intel_quark_mfd_remove,
+};
+
+module_pci_driver(intel_quark_mfd_driver);
+
+MODULE_AUTHOR("Raymond Tan <raymond.tan@intel.com>");
+MODULE_DESCRIPTION("Intel Quark MFD PCI driver for I2C & GPIO");
+MODULE_LICENSE("GPL v2");