[PATCH 1/4] mfd: Kontron PLD mfd driver

From: Kevin Strasser
Date: Mon Apr 08 2013 - 13:18:38 EST


From: Michael Brunner <michael.brunner@xxxxxxxxxxx>

Add core MFD driver for the on-board PLD found on some Kontron embedded
modules. The PLD device may provide functions like watchdog, GPIO, UART
and I2C bus.

The following modules are supported:
* COMe-bIP#
* COMe-bPC2 (ETXexpress-PC)
* COMe-bSC# (ETXexpress-SC T#)
* COMe-cCT6
* COMe-cDC2 (microETXexpress-DC)
* COMe-cPC2 (microETXexpress-PC)
* COMe-mCT10
* COMe-mSP1 (nanoETXexpress-SP)
* COMe-mTT10 (nanoETXexpress-TT)
* ETX-OH

Signed-off-by: Michael Brunner <michael.brunner@xxxxxxxxxxx>
Signed-off-by: Kevin Strasser <kevin.strasser@xxxxxxxxxxxxxxx>
---
drivers/mfd/Kconfig | 23 +
drivers/mfd/Makefile | 1 +
drivers/mfd/kempld-core.c | 1088 ++++++++++++++++++++++++++++++++++++++++++++
include/linux/mfd/kempld.h | 152 +++++++
4 files changed, 1264 insertions(+)
create mode 100644 drivers/mfd/kempld-core.c
create mode 100644 include/linux/mfd/kempld.h

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index c346941..2491843 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -912,6 +912,29 @@ config MFD_TIMBERDALE
The timberdale FPGA can be found on the Intel Atom development board
for in-vehicle infontainment, called Russellville.

+config MFD_KEMPLD
+ tristate "Support for Kontron module PLD device"
+ select MFD_CORE
+ help
+ This is the core driver for the PLD device found on some Kontron
+ ETX and COMexpress (ETXexpress) modules. The PLD device may provide
+ functions like watchdog, GPIO, UART and I2C bus.
+
+ The following modules are supported:
+ * COMe-bIP#
+ * COMe-bPC2 (ETXexpress-PC)
+ * COMe-bSC# (ETXexpress-SC T#)
+ * COMe-cCT6
+ * COMe-cDC2 (microETXexpress-DC)
+ * COMe-cPC2 (microETXexpress-PC)
+ * COMe-mCT10
+ * COMe-mSP1 (nanoETXexpress-SP)
+ * COMe-mTT10 (nanoETXexpress-TT)
+ * ETX-OH
+
+ This driver can also be built as a module. If so, the module
+ will be called kempld-core.
+
config LPC_SCH
tristate "Intel SCH LPC"
depends on PCI && GENERIC_HARDIRQS
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index b90409c..cb1cb16 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -123,6 +123,7 @@ obj-$(CONFIG_MFD_DB8500_PRCMU) += db8500-prcmu.o
obj-$(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_LPC_SCH) += lpc_sch.o
obj-$(CONFIG_LPC_ICH) += lpc_ich.o
obj-$(CONFIG_MFD_RDC321X) += rdc321x-southbridge.o
diff --git a/drivers/mfd/kempld-core.c b/drivers/mfd/kempld-core.c
new file mode 100644
index 0000000..778e26b
--- /dev/null
+++ b/drivers/mfd/kempld-core.c
@@ -0,0 +1,1088 @@
+/*
+ * kempld-core.c - Kontron PLD MFD core driver
+ *
+ * Copyright (c) 2010-2013 Kontron Europe GmbH
+ * Author: Michael Brunner <michael.brunner@xxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License 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; see the file COPYING. If not, write to
+ * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/dmi.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/sched.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/kempld.h>
+
+#define KEMPLD_MAINTAIN_EFT_COMPATIBILITY 1
+
+static int kempld_platform_device_register(const struct dmi_system_id *id);
+static int kempld_get_mutex_set_index_generic(struct kempld_device_data *pld,
+ u8 index, unsigned int timeout);
+static void kempld_release_mutex_generic(struct kempld_device_data *pld);
+
+static int kempld_get_info(struct kempld_device_data *pld);
+static int kempld_get_info_NOW1(struct kempld_device_data *pld);
+static int kempld_get_info_generic(struct kempld_device_data *pld);
+static int kempld_get_features(struct kempld_device_data *pld);
+static int kempld_register_cells_generic(struct kempld_device_data *pld);
+static int kempld_register_cells_NOW1(struct kempld_device_data *pld);
+
+#define MAX_IDENT_LEN 4
+static char force_ident[MAX_IDENT_LEN + 1] = "";
+module_param_string(force_ident, force_ident, sizeof(force_ident), 0);
+MODULE_PARM_DESC(force_ident, "Force detection of specific product");
+
+/* this option is only here for debugging and should never be needed in
+ * production environments */
+static bool force_unlock;
+module_param(force_unlock, bool, 0);
+MODULE_PARM_DESC(force_unlock, "Force breaking the semaphore on driver load");
+
+/* this is the default CPLD configuration unless something else is defined */
+static const struct kempld_platform_data kempld_platform_data_generic = {
+ .pld_clock = 33333333,
+ .ioport = 0xa80,
+ .force_index_write = 0,
+ .get_mutex_set_index = kempld_get_mutex_set_index_generic,
+ .release_mutex = kempld_release_mutex_generic,
+ .get_info = kempld_get_info_generic,
+ .register_cells = kempld_register_cells_generic,
+};
+
+/* the COMe-mSP1 (nanoETXexpress-SP) has an earlier version of the CPLD that
+ * works a bit different */
+static const struct kempld_platform_data kempld_platform_data_NOW1 = {
+ .pld_clock = 33333333,
+ .ioport = 0xa80,
+ .force_index_write = 1,
+ .get_mutex_set_index = NULL,
+ .release_mutex = NULL,
+ .get_info = kempld_get_info_NOW1,
+ .register_cells = kempld_register_cells_NOW1,
+};
+
+static const struct dmi_system_id kempld_boardids[] = {
+ {
+ .callback = kempld_platform_device_register,
+ .ident = "CCR2",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
+ DMI_MATCH(DMI_BOARD_NAME, "COMe-bIP2"),
+ },
+ },
+ {
+ .callback = kempld_platform_device_register,
+ .ident = "CCR6",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
+ DMI_MATCH(DMI_BOARD_NAME, "COMe-bIP6"),
+ },
+ },
+ {
+ .callback = kempld_platform_device_register,
+ .ident = "CHR2",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
+ DMI_MATCH(DMI_BOARD_NAME, "ETXexpress-SC T2"),
+ },
+ },
+ {
+ .callback = kempld_platform_device_register,
+ .ident = "CHR2",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
+ DMI_MATCH(DMI_BOARD_NAME, "ETXe-SC T2"),
+ },
+ },
+ {
+ .callback = kempld_platform_device_register,
+ .ident = "CHR2",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
+ DMI_MATCH(DMI_BOARD_NAME, "COMe-bSC2"),
+ },
+ },
+ {
+ .callback = kempld_platform_device_register,
+ .ident = "CHR6",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
+ DMI_MATCH(DMI_BOARD_NAME, "ETXexpress-SC T6"),
+ },
+ },
+ {
+ .callback = kempld_platform_device_register,
+ .ident = "CHR6",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
+ DMI_MATCH(DMI_BOARD_NAME, "ETXe-SC T6"),
+ },
+ },
+ {
+ .callback = kempld_platform_device_register,
+ .ident = "CHR6",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
+ DMI_MATCH(DMI_BOARD_NAME, "COMe-bSC6"),
+ },
+ },
+ {
+ .callback = kempld_platform_device_register,
+ .ident = "CNTG",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
+ DMI_MATCH(DMI_BOARD_NAME, "ETXexpress-PC"),
+ },
+ },
+ {
+ .callback = kempld_platform_device_register,
+ .ident = "CNTG",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
+ DMI_MATCH(DMI_BOARD_NAME, "COMe-bPC2"),
+ },
+ },
+ {
+ .callback = kempld_platform_device_register,
+ .ident = "CNTX",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
+ DMI_MATCH(DMI_BOARD_NAME, "PXT"),
+ },
+ },
+ {
+ .callback = kempld_platform_device_register,
+ .ident = "FRI2",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
+ DMI_MATCH(DMI_BIOS_VERSION, "FRI2"),
+ },
+ },
+ {
+ .callback = kempld_platform_device_register,
+ .ident = "FRI2",
+ .matches = {
+ DMI_MATCH(DMI_PRODUCT_NAME, "Fish River Island II"),
+ },
+ },
+ {
+ .callback = kempld_platform_device_register,
+ .ident = "MBR1",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
+ DMI_MATCH(DMI_BOARD_NAME, "ETX-OH"),
+ },
+ },
+ {
+ .callback = kempld_platform_device_register,
+ .ident = "NOW1",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
+ DMI_MATCH(DMI_BOARD_NAME, "nanoETXexpress-SP"),
+ },
+ .driver_data = (void *)&kempld_platform_data_NOW1,
+ },
+ {
+ .callback = kempld_platform_device_register,
+ .ident = "NOW1",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
+ DMI_MATCH(DMI_BOARD_NAME, "COMe-mSP1"),
+ },
+ .driver_data = (void *)&kempld_platform_data_NOW1,
+ },
+ {
+ .callback = kempld_platform_device_register,
+ .ident = "NTC1",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
+ DMI_MATCH(DMI_BOARD_NAME, "nanoETXexpress-TT"),
+ },
+ },
+ {
+ .callback = kempld_platform_device_register,
+ .ident = "NTC1",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
+ DMI_MATCH(DMI_BOARD_NAME, "nETXe-TT"),
+ },
+ },
+ {
+ .callback = kempld_platform_device_register,
+ .ident = "NTC1",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
+ DMI_MATCH(DMI_BOARD_NAME, "COMe-mTT"),
+ },
+ },
+ {
+ .callback = kempld_platform_device_register,
+ .ident = "NUP1",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
+ DMI_MATCH(DMI_BOARD_NAME, "COMe-mCT"),
+ },
+ },
+ {
+ .callback = kempld_platform_device_register,
+ .ident = "UNP1",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
+ DMI_MATCH(DMI_BOARD_NAME, "microETXexpress-DC"),
+ },
+ },
+ {
+ .callback = kempld_platform_device_register,
+ .ident = "UNP1",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
+ DMI_MATCH(DMI_BOARD_NAME, "COMe-cDC2"),
+ },
+ },
+ {
+ .callback = kempld_platform_device_register,
+ .ident = "UNTG",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
+ DMI_MATCH(DMI_BOARD_NAME, "microETXexpress-PC"),
+ },
+ },
+ {
+ .callback = kempld_platform_device_register,
+ .ident = "UNTG",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
+ DMI_MATCH(DMI_BOARD_NAME, "COMe-cPC2"),
+ },
+ },
+ {
+ .callback = kempld_platform_device_register,
+ .ident = "UUP6",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "Kontron"),
+ DMI_MATCH(DMI_BOARD_NAME, "COMe-cCT6"),
+ },
+ },
+ {}
+};
+
+static struct kempld_platform_data kempld_platform_data;
+
+static struct mfd_cell kempld_cell_i2c = {
+ .name = "kempld-i2c",
+};
+
+static struct mfd_cell kempld_cell_wdt = {
+ .name = "kempld-wdt",
+};
+
+static struct mfd_cell kempld_cell_NOW1_wdt = {
+ .name = "kempld_now1-wdt",
+};
+
+static struct mfd_cell kempld_cell_gpio = {
+ .name = "kempld-gpio",
+};
+
+static struct mfd_cell kempld_cell_uart = {
+ .name = "kempld-uart",
+};
+
+static struct mfd_cell kempld_cell_NOW1_gpio = {
+ .name = "kempld_now1-gpio",
+};
+
+static struct platform_device *kempld_pdev;
+
+/**
+ * kempld_read8 - read 8 bit register
+ * @pld: kempld_device_data structure describing the PLD
+ * @index: register index on the chip
+ *
+ * This function reads an 8 bit register of the PLD and returns its value.
+ *
+ * In order for this function to work correctly, kempld_try_get_mutex_set_index
+ * or kempld_get_mutex_set_index has to be called before calling the function
+ * to acquire the mutex. Afterwards the mutex has to be released with
+ * kempld_release_mutex.
+ */
+u8 kempld_read8(struct kempld_device_data *pld, u8 index)
+{
+ kempld_set_index(pld, index);
+
+ return ioread8(pld->io_data);
+}
+EXPORT_SYMBOL(kempld_read8);
+
+/**
+ * kempld_write8 - write 8 bit register
+ * @pld: kempld_device_data structure describing the PLD
+ * @index: register index on the chip
+ * @data: new register value
+ *
+ * This function writes an 8 bit register of the PLD.
+ *
+ * In order for this function to work correctly, kempld_try_get_mutex_set_index
+ * or kempld_get_mutex_set_index has to be called before calling the function
+ * to acquire the mutex. Afterwards the mutex has to be released with
+ * kempld_release_mutex.
+ */
+void kempld_write8(struct kempld_device_data *pld, u8 index, u8 data)
+{
+ kempld_set_index(pld, index);
+
+ iowrite8(data, pld->io_data);
+}
+EXPORT_SYMBOL(kempld_write8);
+
+/**
+ * kempld_read16 - read 16 bit register
+ * @pld: kempld_device_data structure describing the PLD
+ * @index: register index on the chip
+ *
+ * This function reads a 16 bit register of the PLD and returns its value.
+ *
+ * In order for this function to work correctly, kempld_try_get_mutex_set_index
+ * or kempld_get_mutex_set_index has to be called before calling the function
+ * to acquire the mutex. Afterwards the mutex has to be released with
+ * kempld_release_mutex.
+ */
+u16 kempld_read16(struct kempld_device_data *pld, u8 index)
+{
+ BUG_ON(index+1 < index);
+
+ return kempld_read8(pld, index) | kempld_read8(pld, index+1) << 8;
+}
+EXPORT_SYMBOL(kempld_read16);
+
+/**
+ * kempld_write16 - write 16 bit register
+ * @pld: kempld_device_data structure describing the PLD
+ * @index: register index on the chip
+ * @data: new register value
+ *
+ * This function writes a 16 bit register of the PLD.
+ *
+ * In order for this function to work correctly, kempld_try_get_mutex_set_index
+ * or kempld_get_mutex_set_index has to be called before calling the function
+ * to acquire the mutex. Afterwards the mutex has to be released with
+ * kempld_release_mutex.
+ */
+void kempld_write16(struct kempld_device_data *pld, u8 index, u16 data)
+{
+ BUG_ON(index+1 < index);
+
+ kempld_write8(pld, index, (u8)data);
+ kempld_write8(pld, index+1, (u8)(data>>8));
+}
+EXPORT_SYMBOL(kempld_write16);
+
+/**
+ * kempld_read32 - read 32 bit register
+ * @pld: kempld_device_data structure describing the PLD
+ * @index: register index on the chip
+ *
+ * This function reads a 32 bit register of the PLD and returns its value.
+ *
+ * In order for this function to work correctly, kempld_try_get_mutex_set_index
+ * or kempld_get_mutex_set_index has to be called before calling the function
+ * to acquire the mutex. Afterwards the mutex has to be released with
+ * kempld_release_mutex.
+ */
+u32 kempld_read32(struct kempld_device_data *pld, u8 index)
+{
+ BUG_ON(index+3 < index);
+
+ return kempld_read16(pld, index) | kempld_read16(pld, index+2) << 16;
+}
+EXPORT_SYMBOL(kempld_read32);
+
+/**
+ * kempld_write32 - write 32 bit register
+ * @pld: kempld_device_data structure describing the PLD
+ * @index: register index on the chip
+ * @data: new register value
+ *
+ * This function writes a 32 bit register of the PLD.
+ *
+ * In order for this function to work correctly, kempld_try_get_mutex_set_index
+ * or kempld_get_mutex_set_index has to be called before calling the function
+ * to acquire the mutex. Afterwards the mutex has to be released with
+ * kempld_release_mutex.
+ */
+void kempld_write32(struct kempld_device_data *pld, u8 index, u32 data)
+{
+ BUG_ON(index+3 < index);
+
+ kempld_write16(pld, index, (u16)data);
+ kempld_write16(pld, index+2, (u16)(data>>16));
+}
+EXPORT_SYMBOL(kempld_write32);
+
+/**
+ * kempld_set_index - change the current register index of the PLD
+ * @pld: kempld_device_data structure describing the PLD
+ * @index: register index on the chip
+ *
+ * This function changes the register index of the PLD.
+ *
+ * If the PLD mutex has been acquired the whole time and the desired index is
+ * already set there might be no actual hardware access done in this function.
+ *
+ * In order for this function to work correctly, kempld_try_get_mutex_set_index
+ * or kempld_get_mutex_set_index has to be called before calling the function
+ * to acquire the mutex. Afterwards the mutex has to be released with
+ * kempld_release_mutex.
+ */
+void kempld_set_index(struct kempld_device_data *pld, u8 index)
+{
+ struct kempld_platform_data *pdata = pld->dev->platform_data;
+
+ BUG_ON(pld->have_mutex == 0);
+
+ if (pld->last_index != index || pdata->force_index_write) {
+ iowrite8(index, pld->io_index);
+ pld->last_index = index;
+ }
+}
+EXPORT_SYMBOL(kempld_set_index);
+
+static int kempld_get_mutex_set_index_generic(struct kempld_device_data *pld,
+ u8 index, unsigned int timeout)
+{
+ struct kempld_platform_data *pdata = pld->dev->platform_data;
+ int data;
+
+ if (!pld->have_mutex) {
+ unsigned long loop_timeout = jiffies + (HZ*timeout)/1000;
+
+ while ((((data = ioread8(pld->io_index)) & KEMPLD_MUTEX_KEY)
+ == KEMPLD_MUTEX_KEY)) {
+ if (timeout != KEMPLD_MUTEX_NOTIMEOUT)
+ if (!time_before(jiffies, loop_timeout))
+ return -ETIMEDOUT;
+
+ /* we will have to wait until mutex is free */
+ spin_unlock_irqrestore(&pld->lock, pld->lock_flags);
+
+ /* give other tasks a chance to release the mutex */
+ schedule_timeout_interruptible(0);
+
+ spin_lock_irqsave(&pld->lock, pld->lock_flags);
+ }
+ } else
+ data = ioread8(pld->io_index);
+
+ if (KEMPLD_MAINTAIN_EFT_COMPATIBILITY
+ || ((pld->last_index != (data & ~KEMPLD_MUTEX_KEY))
+ || pdata->force_index_write)) {
+ iowrite8(index, pld->io_index);
+ pld->last_index = index;
+ }
+
+ return 0;
+}
+
+/**
+ * kempld_get_mutex_set_index - acquire the PLD mutex and set register index
+ * @pld: kempld_device_data structure describing the PLD
+ * @index: register index on the chip
+ *
+ * This function acquires a PLD spinlock and the PLD mutex, additionally it
+ * also changes the register index. In order to do no unnecessary write cycles
+ * the index provided to this function should be the same that will be used
+ * with the first PLD access that is done afterwards.
+ *
+ * The function will block for at least 10 seconds if the mutex can't be
+ * acquired and issue a warning in that case. In order to not lock the device,
+ * the function assumes that the mutex has been acquired in that case.
+ *
+ * To release the spinlock and mutex kempld_release_mutex can be called.
+ * The spinlock and mutex should only be kept for a few milliseconds, in order
+ * to give other drivers a chance to work with the PLD.
+ */
+inline void kempld_get_mutex_set_index(struct kempld_device_data *pld,
+ u8 index)
+{
+ struct kempld_platform_data *pdata = pld->dev->platform_data;
+
+ spin_lock_irqsave(&pld->lock, pld->lock_flags);
+
+ if (pdata->get_mutex_set_index) {
+ /* use a long timeout here as this shouldn't fail */
+ if (pdata->get_mutex_set_index(pld, index, 10000))
+ dev_warn(pld->dev, "semaphore broken!\n");
+
+ pld->have_mutex = 1;
+ } else {
+ pld->have_mutex = 1;
+ kempld_set_index(pld, index);
+ }
+}
+EXPORT_SYMBOL(kempld_get_mutex_set_index);
+
+/**
+ * kempld_try_get_mutex_set_index - try to acquire the PLD mutex and set
+ * register index
+ * @pld: kempld_device_data structure describing the PLD
+ * @index: register index on the chip
+ * @timeout: timeout value
+ *
+ * This function tries to acquire a PLD spinlock and the PLD mutex,
+ * additionally it also changes the register index. In order to do no
+ * unnecessary write cycles the index provided to this function should be the
+ * same that will be used with the first PLD access that is done afterwards.
+ *
+ * The function will try to get the mutex for the time defined with the timeout
+ * parameter until it returns with -ETIMEDOUT. When the mutex is successfully
+ * acquired the function returns immediately with the return value 0.
+ *
+ * To release the spinlock and mutex kempld_release_mutex can be called.
+ * The spinlock and mutex should only be kept for a few milliseconds, in order
+ * to give other drivers a chance to work with the PLD.
+ */
+inline int kempld_try_get_mutex_set_index(struct kempld_device_data *pld,
+ u8 index, unsigned int timeout)
+{
+ int ret;
+ struct kempld_platform_data *pdata = pld->dev->platform_data;
+
+ spin_lock_irqsave(&pld->lock, pld->lock_flags);
+
+ if (pdata->get_mutex_set_index) {
+ ret = pdata->get_mutex_set_index(pld, index, timeout);
+ if (ret == 0)
+ pld->have_mutex = 1;
+ } else {
+ pld->have_mutex = 1;
+ kempld_set_index(pld, index);
+ ret = 0;
+ }
+
+ if (ret != 0)
+ spin_unlock_irqrestore(&pld->lock, pld->lock_flags);
+
+ return ret;
+}
+EXPORT_SYMBOL(kempld_try_get_mutex_set_index);
+
+static void kempld_release_mutex_generic(struct kempld_device_data *pld)
+{
+ iowrite8(pld->last_index | KEMPLD_MUTEX_KEY, pld->io_index);
+}
+
+/**
+ * kempld_release_mutex - release PLD mutex
+ * @pld: kempld_device_data structure describing the PLD
+ *
+ * This function releases the spinlock und mutex previously acquired with the
+ * kempld_get_mutex_set_index or kempld_try_get_mutex_set_index functions.
+ */
+inline void kempld_release_mutex(struct kempld_device_data *pld)
+{
+ struct kempld_platform_data *pdata = pld->dev->platform_data;
+
+ BUG_ON(pld->have_mutex == 0);
+
+ if (pdata->release_mutex)
+ pdata->release_mutex(pld);
+
+ pld->have_mutex = 0;
+
+ spin_unlock_irqrestore(&pld->lock, pld->lock_flags);
+}
+EXPORT_SYMBOL(kempld_release_mutex);
+
+/**
+ * kempld_get_info - update device specific information
+ * @pld: kempld_device_data structure describing the PLD
+ *
+ * This function calls the configured board specific kempld_get_info_XXXX
+ * function which is responsible for gathering information about the specific
+ * hardware. The information is then stored within the pld structure.
+ */
+static int kempld_get_info(struct kempld_device_data *pld)
+{
+ struct kempld_platform_data *pdata = pld->dev->platform_data;
+
+ BUG_ON(pdata->get_info == NULL);
+
+ if (pdata->get_info)
+ return pdata->get_info(pld);
+
+ return -EIO;
+}
+
+static int kempld_get_info_NOW1(struct kempld_device_data *pld)
+{
+ kempld_get_mutex_set_index(pld, KEMPLD_VERSION_NOW1);
+
+ pld->info.major = kempld_read8(pld, KEMPLD_VERSION_NOW1);
+ pld->info.minor = 0;
+
+ pld->info.buildnr = kempld_read8(pld, KEMPLD_BUILDNR_NOW1);
+
+ pld->info.number = 0;
+ pld->info.type = 0x0;
+
+ pld->info.spec_major = 0;
+ pld->info.spec_minor = 0;
+
+ kempld_release_mutex(pld);
+
+ return 0;
+}
+
+static int kempld_get_info_generic(struct kempld_device_data *pld)
+{
+ u16 data;
+
+ kempld_get_mutex_set_index(pld, KEMPLD_VERSION);
+
+ data = kempld_read16(pld, KEMPLD_VERSION);
+ pld->info.minor = KEMPLD_VERSION_GET_MINOR(data);
+ pld->info.major = KEMPLD_VERSION_GET_MAJOR(data);
+ pld->info.number = KEMPLD_VERSION_GET_NUMBER(data);
+ pld->info.type = KEMPLD_VERSION_GET_TYPE(data);
+ pld->info.buildnr = kempld_read16(pld, KEMPLD_BUILDNR);
+
+ data = kempld_read8(pld, KEMPLD_SPEC);
+ if (data == 0xff) {
+ pld->info.spec_minor = 0;
+ pld->info.spec_major = 1;
+ } else {
+ pld->info.spec_minor = KEMPLD_SPEC_GET_MINOR(data);
+ pld->info.spec_major = KEMPLD_SPEC_GET_MAJOR(data);
+ }
+
+ kempld_release_mutex(pld);
+
+ return 0;
+}
+
+/**
+ * kempld_get_features - retrieve features supported by device
+ * @pld: kempld_device_data structure describing the PLD
+ *
+ * This function tries to detect the features supported by the PLD device
+ */
+static int kempld_get_features(struct kempld_device_data *pld)
+{
+ if (pld->info.spec_major > 0) {
+ kempld_get_mutex_set_index(pld, KEMPLD_FEATURE);
+
+ pld->feature_mask = kempld_read16(pld, KEMPLD_FEATURE);
+
+ kempld_release_mutex(pld);
+ } else {
+ /* No way to automatically detect the features, they have to
+ * be specified during cell registration */
+ pld->feature_mask = 0;
+ }
+
+ return 0;
+}
+
+/*
+ * kempld_register_cells - register cell drivers
+ *
+ * This function registers cell drivers for the detected hardware by calling
+ * the configured kempld_register_cells_XXXX function which is responsible
+ * to detect and register the needed cell drivers.
+ */
+static int kempld_register_cells(struct kempld_device_data *pld)
+{
+ struct kempld_platform_data *pdata = pld->dev->platform_data;
+
+ if (pdata->register_cells)
+ return pdata->register_cells(pld);
+
+ dev_warn(pld->dev, "no subdevices are supported\n");
+
+ return -ENODEV;
+}
+
+static int kempld_register_cells_NOW1(struct kempld_device_data *pld)
+{
+
+ /* The NOW1 has a fixed feature set that cannot be detected */
+
+ pld->feature_mask = KEMPLD_FEATURE_BIT_WATCHDOG
+ | KEMPLD_FEATURE_BIT_GPIO;
+
+ mfd_add_devices(pld->dev, -1, &kempld_cell_NOW1_wdt,
+ 1, NULL, 0, NULL);
+ dev_info(pld->dev, "registered watchdog support\n");
+
+ mfd_add_devices(pld->dev, -1, &kempld_cell_NOW1_gpio,
+ 1, NULL, 0, NULL);
+ dev_info(pld->dev, "registered GPIO support\n");
+
+ return 0;
+}
+
+static int kempld_register_cells_generic(struct kempld_device_data *pld)
+{
+ if (pld->feature_mask & KEMPLD_FEATURE_BIT_I2C) {
+ mfd_add_devices(pld->dev, -1, &kempld_cell_i2c,
+ 1, NULL, 0, NULL);
+ dev_info(pld->dev, "registered I2C support\n");
+ }
+
+ if (pld->feature_mask & KEMPLD_FEATURE_BIT_WATCHDOG) {
+ mfd_add_devices(pld->dev, -1, &kempld_cell_wdt,
+ 1, NULL, 0, NULL);
+ dev_info(pld->dev, "registered watchdog support\n");
+ }
+
+ if (pld->feature_mask & KEMPLD_FEATURE_BIT_GPIO) {
+ mfd_add_devices(pld->dev, -1, &kempld_cell_gpio,
+ 1, NULL, 0, NULL);
+ dev_info(pld->dev, "registered GPIO support\n");
+ }
+
+ if (pld->feature_mask & KEMPLD_FEATURE_MASK_UART) {
+ mfd_add_devices(pld->dev, -1, &kempld_cell_uart,
+ 1, NULL, 0, NULL);
+ dev_info(pld->dev, "registered UART support\n");
+ }
+
+ return 0;
+}
+
+static int kempld_detect_device(struct kempld_device_data *pld)
+{
+ struct kempld_platform_data *pdata = pld->dev->platform_data;
+ int ret;
+ u8 index_reg;
+ int lock_broken = 0;
+ char *typestring;
+
+ spin_lock_irqsave(&pld->lock, pld->lock_flags);
+
+ /* Check for empty IO space */
+ index_reg = ioread8(pld->io_index);
+ if ((index_reg == 0xff) && (ioread8(pld->io_data) == 0xff)) {
+ ret = -ENODEV;
+ spin_unlock_irqrestore(&pld->lock, pld->lock_flags);
+ goto err_empty_io;
+ }
+
+ pld->last_index = index_reg & ~KEMPLD_MUTEX_KEY;
+
+ if ((index_reg & KEMPLD_MUTEX_KEY) == 0x00) {
+ /* lock is currently not acquired by anyone else */
+ /* on some PLD revisions we now already have acquired the
+ * mutex, so release it before continuing */
+
+ /* We have to set the index first, to be sure to have the
+ * lock in all HW revisions */
+ iowrite8(pld->last_index, pld->io_index);
+
+ if (pdata->release_mutex)
+ pdata->release_mutex(pld);
+ }
+
+ spin_unlock_irqrestore(&pld->lock, pld->lock_flags);
+
+ /* Now really try to get the mutex, but use a timeout for the case it
+ * doesn't work */
+ ret = kempld_try_get_mutex_set_index(pld, pld->last_index, 1000);
+ if (ret) {
+ dev_warn(pld->dev,
+ "timeout while waiting for device semaphore\n");
+ if (force_unlock) {
+ /* We pretend to have aqcuired the lock and go on in
+ * the hope that it was only a single error */
+ dev_warn(pld->dev,
+ "force_unlock enabled - ignoring semaphore\n");
+ spin_lock_irqsave(&pld->lock, pld->lock_flags);
+ pld->have_mutex = 1;
+ lock_broken = 1;
+ } else
+ goto err_get_mutex;
+ }
+
+ /* Check if the mutex works as expected */
+ /* This check is left out if the lock has been broken, as it may fail
+ * if the lock gets released in the meantime by a parallel process */
+ if (pdata->get_mutex_set_index && !lock_broken) {
+ /* pretend to not have the mutex and try to get it, which
+ * should fail if everything works */
+ pld->have_mutex = 0;
+ if (pdata->get_mutex_set_index(pld, pld->last_index, 0)
+ != -ETIMEDOUT) {
+ dev_err(pld->dev, "semaphore function check failed\n");
+ ret = -EIO;
+
+ /* release the mutex anyway to be sure everything is
+ * cleaned up */
+ kempld_release_mutex(pld);
+
+ goto err_check_mutex;
+ }
+ pld->have_mutex = 1;
+ }
+
+ kempld_release_mutex(pld);
+
+ /* from here on it should be save to rely on the device semaphore */
+
+ ret = kempld_get_info(pld);
+ if (ret)
+ goto err_get_info;
+
+ switch (pld->info.type) {
+ case 0:
+ typestring = "release";
+ break;
+ case 1:
+ typestring = "debug";
+ break;
+ case 2:
+ typestring = "custom";
+ break;
+ default:
+ dev_warn(pld->dev, "PLD type not specified");
+ typestring = "unspecified";
+ }
+
+ ret = kempld_get_features(pld);
+ if (ret)
+ goto err_get_features;
+
+ dev_info(pld->dev, "found Kontron PLD %d\n", pld->info.number);
+ dev_info(pld->dev, "%s version %d.%d build %d, specification %d.%d\n",
+ typestring, pld->info.major, pld->info.minor,
+ pld->info.buildnr, pld->info.spec_major,
+ pld->info.spec_minor);
+
+ ret = kempld_register_cells(pld);
+ if (ret)
+ goto err_register_functions;
+
+ return 0;
+
+err_register_functions:
+err_get_features:
+err_get_info:
+err_check_mutex:
+err_get_mutex:
+err_empty_io:
+ return ret;
+}
+
+static int kempld_probe(struct platform_device *pdev)
+{
+ struct kempld_platform_data *pdata = pdev->dev.platform_data;
+ struct resource *ioport;
+ struct kempld_device_data *pld;
+ int ret;
+
+ dev_dbg(&pdev->dev, "probing for Kontron PLD on %s\n",
+ pdata->board_id->ident);
+
+ pld = kzalloc(sizeof(struct kempld_device_data), GFP_KERNEL);
+ if (pld == NULL) {
+ dev_err(&pdev->dev, "unable to get memory for device data\n");
+ ret = -ENOMEM;
+ goto err_alloc_dev_data;
+ }
+
+ ioport = platform_get_resource(pdev, IORESOURCE_IO, 0);
+ if (!ioport) {
+ ret = -EINVAL;
+ goto err_get_resource;
+ }
+
+ pld->io_base = ioport_map(ioport->start, ioport->end - ioport->start);
+ if (!pld->io_base) {
+ ret = -ENOMEM;
+ goto err_iomap;
+ }
+
+ pld->io_index = pld->io_base;
+ pld->io_data = pld->io_base + 1;
+
+ pld->pld_clock = pdata->pld_clock;
+
+ spin_lock_init(&pld->lock);
+
+ pld->dev = &pdev->dev;
+
+ platform_set_drvdata(pdev, pld);
+
+ ret = kempld_detect_device(pld);
+ if (ret)
+ goto err_detect_device;
+
+ return 0;
+
+err_detect_device:
+ ioport_unmap(pld->io_base);
+err_iomap:
+err_get_resource:
+ kfree(pld);
+err_alloc_dev_data:
+ return ret;
+}
+
+static int kempld_remove(struct platform_device *pdev)
+{
+ struct kempld_device_data *pld = platform_get_drvdata(pdev);
+
+ if (pld->have_mutex)
+ kempld_release_mutex(pld);
+
+ mfd_remove_devices(&pdev->dev);
+ platform_set_drvdata(pdev, NULL);
+
+ ioport_unmap(pld->io_base);
+
+ kfree(pld);
+
+ return 0;
+}
+
+static struct platform_driver kempld_driver = {
+ .driver = {
+ .name = "kempld",
+ .owner = THIS_MODULE,
+ },
+ .probe = kempld_probe,
+ .remove = kempld_remove,
+};
+
+static int kempld_platform_device_register(const struct dmi_system_id *id)
+{
+ struct platform_device *pdev;
+ static struct resource resource[1];
+ int ret = 0;
+
+ /* check if we already registered a kempld platform device,
+ * there can only be one */
+ if (kempld_pdev != NULL) {
+ ret = -EINVAL;
+ goto err_device_already_registered;
+ }
+
+ /* use the generic platform data unless something else is specified */
+ if (id->driver_data != NULL)
+ memcpy(&kempld_platform_data, id->driver_data,
+ sizeof(kempld_platform_data));
+ else
+ memcpy(&kempld_platform_data, &kempld_platform_data_generic,
+ sizeof(kempld_platform_data));
+
+
+ pdev = platform_device_alloc("kempld", -1);
+ if (!pdev) {
+ ret = -ENOMEM;
+ goto err_device_alloc_failed;
+ }
+
+ kempld_platform_data.board_id = id;
+
+ ret = platform_device_add_data(pdev, &kempld_platform_data,
+ sizeof(kempld_platform_data));
+ if (ret)
+ goto err_add_data_failed;
+
+ resource[0].start = kempld_platform_data.ioport;
+ resource[0].end = kempld_platform_data.ioport + 1;
+ resource[0].flags = IORESOURCE_IO;
+
+ ret = platform_device_add_resources(pdev, resource, 1);
+ if (ret)
+ goto err_device_add_resources;
+
+ ret = platform_device_add(pdev);
+ if (ret)
+ goto err_device_register_failed;
+
+ kempld_pdev = pdev;
+
+ return 0;
+
+err_device_register_failed:
+err_device_add_resources:
+err_add_data_failed:
+ platform_device_put(pdev);
+err_device_alloc_failed:
+err_device_already_registered:
+ return ret;
+}
+
+static int __init kempld_init(void)
+{
+ int ret;
+
+ ret = platform_driver_register(&kempld_driver);
+ if (ret)
+ goto err_platform_driver_register;
+
+ /* check force parameter if a specific implementation should be
+ * probed */
+ if (force_ident[0]) {
+ int found = 0;
+ const struct dmi_system_id *d;
+ for (d = kempld_boardids; d->matches[0].slot != DMI_NONE; d++)
+ if (strstr(d->ident, force_ident)) {
+ found++;
+ if (d->callback && d->callback(d))
+ break;
+ }
+
+ if (!found)
+ goto err_device_not_found;
+
+ return 0;
+ }
+
+ /* try to autodetect the board */
+ if (dmi_check_system(kempld_boardids))
+ return 0;
+
+err_device_not_found:
+ platform_driver_unregister(&kempld_driver);
+ ret = -ENODEV;
+err_platform_driver_register:
+ return ret;
+}
+
+static void __exit kempld_exit(void)
+{
+ /* unregister device first */
+ if (kempld_pdev) {
+ platform_device_unregister(kempld_pdev);
+ kempld_pdev = NULL;
+ }
+
+ platform_driver_unregister(&kempld_driver);
+}
+
+module_init(kempld_init);
+module_exit(kempld_exit);
+
+MODULE_DESCRIPTION("KEM PLD Core Driver");
+MODULE_AUTHOR("Michael Brunner <michael.brunner@xxxxxxxxxxx>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:kempld-core");
diff --git a/include/linux/mfd/kempld.h b/include/linux/mfd/kempld.h
new file mode 100644
index 0000000..58ebba5
--- /dev/null
+++ b/include/linux/mfd/kempld.h
@@ -0,0 +1,152 @@
+/*
+ * linux/mfd/kempld.h - Kontron PLD driver definitions
+ *
+ * Copyright (c) 2010-2012 Kontron Europe GmbH
+ * Author: Michael Brunner <michael.brunner@xxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License 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; see the file COPYING. If not, write to
+ * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef _LINUX_MFD_KEMPLD_H_
+#define _LINUX_MFD_KEMPLD_H_
+
+/* COMe-mSP1 (nanoETXexpress) specific definitions */
+#define KEMPLD_VERSION_NOW1 0x00
+#define KEMPLD_BUILDNR_NOW1 0x02
+
+/* generic register definitions */
+#define KEMPLD_MUTEX_KEY 0x80
+#define KEMPLD_VERSION 0x00
+#define KEMPLD_VERSION_LSB 0x00
+#define KEMPLD_VERSION_MSB 0x01
+#define KEMPLD_VERSION_GET_MINOR(x) (x & 0x1f)
+#define KEMPLD_VERSION_GET_MAJOR(x) ((x >> 5) & 0x1f)
+#define KEMPLD_VERSION_GET_NUMBER(x) ((x >> 10) & 0xf)
+#define KEMPLD_VERSION_GET_TYPE(x) ((x >> 14) & 0x3)
+#define KEMPLD_BUILDNR 0x02
+#define KEMPLD_BUILDNR_LSB 0x02
+#define KEMPLD_BUILDNR_MSB 0x03
+#define KEMPLD_FEATURE 0x04
+#define KEMPLD_FEATURE_LSB 0x04
+#define KEMPLD_FEATURE_MSB 0x05
+#define KEMPLD_FEATURE_BIT_I2C (1 << 0)
+#define KEMPLD_FEATURE_BIT_WATCHDOG (1 << 1)
+#define KEMPLD_FEATURE_BIT_GPIO (1 << 2)
+#define KEMPLD_FEATURE_MASK_UART (7 << 3)
+#define KEMPLD_FEATURE_BIT_NMI (1 << 8)
+#define KEMPLD_FEATURE_BIT_SMI (1 << 9)
+#define KEMPLD_FEATURE_BIT_SCI (1 << 10)
+#define KEMPLD_SPEC 0x06
+#define KEMPLD_SPEC_GET_MINOR(x) (x & 0x0f)
+#define KEMPLD_SPEC_GET_MAJOR(x) ((x >> 4) & 0x0f)
+#define KEMPLD_IRQ_GPIO 0x35
+#define KEMPLD_IRQ_I2C 0x36
+#define KEMPLD_CFG 0x37
+#define KEMPLD_CFG_GPIO_I2C_MUX (1<<0)
+#define KEMPLD_CFG_BIOS_WP (1<<7)
+
+#define KEMPLD_TYPE_RELEASE 0x0
+#define KEMPLD_TYPE_DEBUG 0x1
+#define KEMPLD_TYPE_CUSTOM 0x2
+
+#define KEMPLD_MUTEX_NOTIMEOUT ((unsigned int)~0)
+
+/**
+ * struct kempld_info - PLD device information structure
+ * @major: PLD major revision
+ * @minor: PLD minor revision
+ * @buildnr: PLD build number
+ * @number: PLD board specific index
+ * @type: PLD type
+ * @spec_major: PLD FW specification major revision
+ * @spec_minor: PLD FW specification minor revision
+ */
+struct kempld_info {
+ unsigned int major;
+ unsigned int minor;
+ unsigned int buildnr;
+ unsigned int number;
+ unsigned int type;
+ unsigned int spec_major;
+ unsigned int spec_minor;
+};
+
+/**
+ * struct kempld_device_data - Internal representation of the PLD device
+ * @io_base: Pointer to the IO memory
+ * @io_index: Pointer to the IO index register
+ * @io_data: Pointer to the IO data register
+ * @pld_clock: PLD clock frequency
+ * @feature_mask: PLD feature mask
+ * @lock: PLD spin-lock
+ * @lock_flags: PLD spin-lock flags
+ * @have_mutex: Bool value that indicates if mutex is aquired
+ * @last_index: Last written index value
+ * @dev: Pointer to kernel device structure
+ * @info: KEMPLD info structure
+ */
+struct kempld_device_data {
+ void __iomem *io_base;
+ void __iomem *io_index;
+ void __iomem *io_data;
+ u32 pld_clock;
+ u32 feature_mask;
+ spinlock_t lock;
+ unsigned long lock_flags;
+ int have_mutex;
+ u8 last_index;
+ struct device *dev;
+ struct kempld_info info;
+};
+
+/**
+ * struct kempld_platform_data - PLD hardware configuration structure
+ * @pld_clock: PLD clock frequency
+ * @ioport: IO address of the PLD
+ * @force_index_write: Force writing the index register on every access
+ * @board_id: Board system ID structure
+ * @release_mutex: Pointer to PLD specific release_mutex function
+ * @get_mutex_set_index: Pointer to PLD specific get_mutex_set_index function
+ * @get_info: Pointer to PLD specific get_info function
+ * @register_cells: Pointer to PLD specific register_cells function
+ *
+ * This structure configures the PLD settings for a specific hardware platform.
+ */
+struct kempld_platform_data {
+ u32 pld_clock;
+ u32 ioport;
+ int force_index_write;
+ const struct dmi_system_id *board_id;
+ void (*release_mutex)(struct kempld_device_data *);
+ int (*get_mutex_set_index)(struct kempld_device_data *, u8,
+ unsigned int);
+ int (*get_info)(struct kempld_device_data *);
+ int (*register_cells)(struct kempld_device_data *);
+};
+
+extern void kempld_set_index(struct kempld_device_data *pld, u8 index);
+extern void kempld_get_mutex_set_index(struct kempld_device_data *pld,
+ u8 index);
+extern int kempld_try_get_mutex_set_index(struct kempld_device_data *pld,
+ u8 index, unsigned int timeout);
+extern void kempld_release_mutex(struct kempld_device_data *pld);
+
+extern u8 kempld_read8(struct kempld_device_data *pld, u8 index);
+extern void kempld_write8(struct kempld_device_data *pld, u8 index, u8 data);
+extern u16 kempld_read16(struct kempld_device_data *pld, u8 index);
+extern void kempld_write16(struct kempld_device_data *pld, u8 index, u16 data);
+extern u32 kempld_read32(struct kempld_device_data *pld, u8 index);
+extern void kempld_write32(struct kempld_device_data *pld, u8 index, u32 data);
+
+#endif /* _LINUX_MFD_KEMPLD_H_ */
--
1.7.9.5

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