[RFC 3/8] mfd: altr_a10sr: Add Altera Arria10 DevKit System Resource Chip

[<tthayer@opensource.altera.com>]

From: Thor Thayer <tthayer@opensource.altera.com>

Add support for the Altera Arria10 Development Kit System Resource
chip which is implemented using a MAX5 as a external gpio extender,
and hardware monitor with the regmap framework over a SPI bus.

Signed-off-by: Thor Thayer <tthayer@opensource.altera.com>
---
 drivers/mfd/Kconfig              |   11 +++
 drivers/mfd/Makefile             |    2 +
 drivers/mfd/altera-a10sr.c       |  177 ++++++++++++++++++++++++++++++++++++++
 include/linux/mfd/altera-a10sr.h |  146 +++++++++++++++++++++++++++++++
 4 files changed, 336 insertions(+)
 create mode 100644 drivers/mfd/altera-a10sr.c
 create mode 100644 include/linux/mfd/altera-a10sr.h

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index eea61e3..d1edf81 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -18,6 +18,17 @@ config MFD_CS5535
 	  This is the core driver for CS5535/CS5536 MFD functions.  This is
           necessary for using the board's GPIO and MFGPT functionality.
 
+config MFD_ALTERA_A10SR
+       bool "Altera Arria10 DevKit System Resource chip"
+       depends on ARCH_SOCFPGA && SPI_MASTER=y
+       select REGMAP_SPI
+       select MFD_CORE
+       help
+         Support for the Altera Arria10 DevKit MAX5 System Resource chip
+         using the SPI interface. This driver provides common support for
+         accessing the external gpio extender (LEDs & buttons) and
+         hw monitor.
+
 config MFD_ACT8945A
 	tristate "Active-semi ACT8945A"
 	select MFD_CORE
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 5eaa6465d..4f1ff91 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -203,3 +203,5 @@ intel-soc-pmic-objs		:= intel_soc_pmic_core.o intel_soc_pmic_crc.o
 intel-soc-pmic-$(CONFIG_INTEL_PMC_IPC)	+= intel_soc_pmic_bxtwc.o
 obj-$(CONFIG_INTEL_SOC_PMIC)	+= intel-soc-pmic.o
 obj-$(CONFIG_MFD_MT6397)	+= mt6397-core.o
+
+obj-$(CONFIG_MFD_ALTERA_A10SR)	+= altera-a10sr.o
diff --git a/drivers/mfd/altera-a10sr.c b/drivers/mfd/altera-a10sr.c
new file mode 100644
index 0000000..13665d4
--- /dev/null
+++ b/drivers/mfd/altera-a10sr.c
@@ -0,0 +1,177 @@
+/*
+ * Copyright Altera Corporation (C) 2014-2016. All Rights Reserved
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPI access for Altera Arria10 MAX5 System Resource Chip
+ *
+ * Adapted from DA9052
+ * Copyright(c) 2011 Dialog Semiconductor Ltd.
+ * Author: David Dajun Chen <dchen@diasemi.com>
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/input.h>
+#include <linux/mfd/altera-a10sr.h>
+#include <linux/mfd/core.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/spi/spi.h>
+
+static const struct mfd_cell altr_a10sr_subdev_info[] = {
+};
+
+static bool altr_a10sr_reg_readable(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case ALTR_A10SR_VERSION_READ:
+	case ALTR_A10SR_LED_RD_REG:
+	case ALTR_A10SR_PBDSW_RD_REG:
+	case ALTR_A10SR_PBDSW_IRQ_CLR_REG:
+	case ALTR_A10SR_PBDSW_IRQ_RD_REG:
+	case ALTR_A10SR_PWR_GOOD1_RD_REG:
+	case ALTR_A10SR_PWR_GOOD2_RD_REG:
+	case ALTR_A10SR_PWR_GOOD3_RD_REG:
+	case ALTR_A10SR_FMCAB_RD_REG:
+	case ALTR_A10SR_HPS_RST_RD_REG:
+	case ALTR_A10SR_USB_QSPI_RD_REG:
+	case ALTR_A10SR_SFPA_RD_REG:
+	case ALTR_A10SR_SFPB_RD_REG:
+	case ALTR_A10SR_I2C_M_RD_REG:
+	case ALTR_A10SR_WARM_RST_RD_REG:
+	case ALTR_A10SR_WR_KEY_RD_REG:
+	case ALTR_A10SR_PMBUS_RD_REG:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static bool altr_a10sr_reg_writeable(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case ALTR_A10SR_LED_WR_REG:
+	case ALTR_A10SR_PBDSW_IRQ_CLR_REG:
+	case ALTR_A10SR_FMCAB_WR_REG:
+	case ALTR_A10SR_HPS_RST_WR_REG:
+	case ALTR_A10SR_USB_QSPI_WR_REG:
+	case ALTR_A10SR_SFPA_WR_REG:
+	case ALTR_A10SR_SFPB_WR_REG:
+	case ALTR_A10SR_WARM_RST_WR_REG:
+	case ALTR_A10SR_WR_KEY_WR_REG:
+	case ALTR_A10SR_PMBUS_WR_REG:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static bool altr_a10sr_reg_volatile(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case ALTR_A10SR_PBDSW_RD_REG:
+	case ALTR_A10SR_PBDSW_IRQ_RD_REG:
+	case ALTR_A10SR_PWR_GOOD1_RD_REG:
+	case ALTR_A10SR_PWR_GOOD2_RD_REG:
+	case ALTR_A10SR_PWR_GOOD3_RD_REG:
+	case ALTR_A10SR_HPS_RST_RD_REG:
+	case ALTR_A10SR_I2C_M_RD_REG:
+	case ALTR_A10SR_WARM_RST_RD_REG:
+	case ALTR_A10SR_WR_KEY_RD_REG:
+	case ALTR_A10SR_PMBUS_RD_REG:
+		return true;
+	default:
+		return false;
+	}
+}
+
+const struct regmap_config altr_a10sr_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+
+	.cache_type = REGCACHE_NONE,
+
+	.use_single_rw = true,
+	.read_flag_mask = 1,
+	.write_flag_mask = 0,
+
+	.max_register = ALTR_A10SR_WR_KEY_RD_REG,
+	.readable_reg = altr_a10sr_reg_readable,
+	.writeable_reg = altr_a10sr_reg_writeable,
+	.volatile_reg = altr_a10sr_reg_volatile,
+
+};
+
+static int altr_a10sr_spi_probe(struct spi_device *spi)
+{
+	int ret;
+	struct altr_a10sr *a10sr;
+
+	a10sr = devm_kzalloc(&spi->dev, sizeof(*a10sr),
+			     GFP_KERNEL);
+	if (!a10sr)
+		return -ENOMEM;
+
+	spi->mode = SPI_MODE_3;
+	spi->bits_per_word = 8;
+	spi_setup(spi);
+
+	a10sr->dev = &spi->dev;
+
+	spi_set_drvdata(spi, a10sr);
+
+	a10sr->regmap = devm_regmap_init_spi(spi, &altr_a10sr_regmap_config);
+	if (IS_ERR(a10sr->regmap)) {
+		ret = PTR_ERR(a10sr->regmap);
+		dev_err(&spi->dev, "Allocate register map Failed: %d\n", ret);
+		return ret;
+	}
+
+	ret = mfd_add_devices(a10sr->dev, PLATFORM_DEVID_AUTO,
+			      altr_a10sr_subdev_info,
+			      ARRAY_SIZE(altr_a10sr_subdev_info),
+			      NULL, 0, NULL);
+	if (ret)
+		dev_err(a10sr->dev, "mfd_add_devices failed: %d\n", ret);
+
+	return ret;
+}
+
+static int altr_a10sr_spi_remove(struct spi_device *spi)
+{
+	mfd_remove_devices(&spi->dev);
+
+	return 0;
+}
+
+static const struct of_device_id altr_a10sr_spi_of_match[] = {
+	{ .compatible = "altr,altr-a10sr" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, altr_a10sr_spi_of_match);
+
+static struct spi_driver altr_a10sr_spi_driver = {
+	.probe = altr_a10sr_spi_probe,
+	.remove = altr_a10sr_spi_remove,
+	.driver = {
+		.name = "altr_a10sr",
+		.of_match_table = altr_a10sr_spi_of_match,
+	},
+};
+
+module_spi_driver(altr_a10sr_spi_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Thor Thayer");
+MODULE_DESCRIPTION("Altera Arria10 DevKit System Resource MFD Driver");
diff --git a/include/linux/mfd/altera-a10sr.h b/include/linux/mfd/altera-a10sr.h
new file mode 100644
index 0000000..7087afc
--- /dev/null
+++ b/include/linux/mfd/altera-a10sr.h
@@ -0,0 +1,146 @@
+/*
+ * Copyright Altera Corporation (C) 2014-2016. All Rights Reserved
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Declarations for Altera Arria10 MAX5 System Resource Chip
+ *
+ * Adapted from DA9052
+ * Copyright(c) 2011 Dialog Semiconductor Ltd.
+ * Author: David Dajun Chen <dchen@diasemi.com>
+ */
+
+#ifndef __MFD_ALTERA_A10SR_H
+#define __MFD_ALTERA_A10SR_H
+
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/completion.h>
+#include <linux/list.h>
+#include <linux/mfd/core.h>
+
+/* Write registers are always on even addresses */
+#define  WRITE_REG_MASK              0xFE
+/* Odd registers are always on odd addresses */
+#define  READ_REG_MASK               0x01
+
+#define ALTR_A10SR_BITS_PER_REGISTER  8
+/*
+ * To find the correct register, we divide the input GPIO by
+ * the number of GPIO in each register. We then need to multiply
+ * by 2 because the reads are at odd addresses.
+ */
+#define ALTR_A10SR_REG_OFFSET(X)     (((X) / ALTR_A10SR_BITS_PER_REGISTER) << 1)
+#define ALTR_A10SR_REG_BIT(X)        ((X) % ALTR_A10SR_BITS_PER_REGISTER)
+#define ALTR_A10SR_REG_BIT_CHG(X, Y) ((X) << ALTR_A10SR_REG_BIT(Y))
+#define ALTR_A10SR_REG_BIT_MASK(X)   (1 << ALTR_A10SR_REG_BIT(X))
+
+/* Arria10 System Controller Register Defines */
+#define ALTR_A10SR_NOP                0x00    /* No Change */
+#define ALTR_A10SR_VERSION_READ       0x01    /* MAX5 Version Read */
+#define ALTR_A10SR_LED_WR_REG         0x02    /* LED - Upper 4 bits */
+#define ALTR_A10SR_LED_RD_REG         0x03    /* LED - Upper 4 bits */
+#define ALTR_A10SR_PBDSW_RD_REG       0x05    /* PB & DIP SW - Input only */
+#define ALTR_A10SR_PBDSW_IRQ_CLR_REG  0x06    /* PB & DIP SW Flag Clear */
+#define ALTR_A10SR_PBDSW_IRQ_RD_REG   0x07    /* PB & DIP SW Flag Read */
+#define ALTR_A10SR_PWR_GOOD1_RD_REG   0x09    /* Power Good1 Read */
+#define ALTR_A10SR_PWR_GOOD2_RD_REG   0x0B    /* Power Good2 Read */
+#define ALTR_A10SR_PWR_GOOD3_RD_REG   0x0D    /* Power Good3 Read */
+#define ALTR_A10SR_FMCAB_WR_REG       0x0E    /* FMCA/B & PCIe Pwr Enable */
+#define ALTR_A10SR_FMCAB_RD_REG       0x0F    /* FMCA/B & PCIe Pwr Enable */
+#define ALTR_A10SR_HPS_RST_WR_REG     0x10    /* HPS Reset */
+#define ALTR_A10SR_HPS_RST_RD_REG     0x11    /* HPS Reset */
+#define ALTR_A10SR_USB_QSPI_WR_REG    0x12    /* USB, BQSPI, FILE Reset */
+#define ALTR_A10SR_USB_QSPI_RD_REG    0x13    /* USB, BQSPI, FILE Reset */
+#define ALTR_A10SR_SFPA_WR_REG        0x14    /* SFPA Control Reg */
+#define ALTR_A10SR_SFPA_RD_REG        0x15    /* SFPA Control Reg */
+#define ALTR_A10SR_SFPB_WR_REG        0x16    /* SFPB Control Reg */
+#define ALTR_A10SR_SFPB_RD_REG        0x17    /* SFPB Control Reg */
+#define ALTR_A10SR_I2C_M_RD_REG       0x19    /* I2C Master Select */
+#define ALTR_A10SR_WARM_RST_WR_REG    0x1A    /* HPS Warm Reset */
+#define ALTR_A10SR_WARM_RST_RD_REG    0x1B    /* HPS Warm Reset */
+#define ALTR_A10SR_WR_KEY_WR_REG      0x1C    /* HPS Warm Reset Key */
+#define ALTR_A10SR_WR_KEY_RD_REG      0x1D    /* HPS Warm Reset Key */
+#define ALTR_A10SR_PMBUS_WR_REG       0x1E    /* HPS PM Bus */
+#define ALTR_A10SR_PMBUS_RD_REG       0x1F    /* HPS PM Bus */
+
+struct altr_a10sr {
+	struct device *dev;
+	struct regmap *regmap;
+};
+
+/* Device I/O API */
+static inline int altr_a10sr_reg_read(struct altr_a10sr *a10sr,
+				      unsigned char reg)
+{
+	int val, ret;
+
+	ret = regmap_read(a10sr->regmap, (reg | READ_REG_MASK), &val);
+	if (ret < 0)
+		return ret;
+
+	return val;
+}
+
+static inline int altr_a10sr_reg_write(struct altr_a10sr *a10sr,
+				       unsigned char reg, unsigned char val)
+{
+	int ret;
+
+	ret = regmap_write(a10sr->regmap, (reg & WRITE_REG_MASK), val);
+	if (ret < 0)
+		return ret;
+
+	return ret;
+}
+
+static inline int altr_a10sr_group_read(struct altr_a10sr *a10sr,
+					unsigned char reg,
+					unsigned int reg_cnt,
+					unsigned char *val)
+{
+	return regmap_bulk_read(a10sr->regmap, reg, val, reg_cnt);
+}
+
+static inline int altr_a10sr_group_write(struct altr_a10sr *a10sr,
+					 unsigned char reg,
+					 unsigned int reg_cnt,
+					 unsigned char *val)
+{
+	return regmap_bulk_write(a10sr->regmap, reg, val, reg_cnt);
+}
+
+static inline int altr_a10sr_reg_update(struct altr_a10sr *a10sr,
+					unsigned char reg,
+					unsigned char bit_mask,
+					unsigned char reg_val)
+{
+	int rval, ret;
+
+	/*
+	 * We can't use the standard regmap_update_bits function because
+	 * the read register has a different address than the write register.
+	 * Therefore, just do a read, modify, write operation here.
+	 */
+	ret = regmap_read(a10sr->regmap, (reg | READ_REG_MASK), &rval);
+	if (ret < 0)
+		return ret;
+
+	rval = ((rval & ~bit_mask) | (reg_val & bit_mask));
+
+	ret = regmap_write(a10sr->regmap, (reg & WRITE_REG_MASK), rval);
+
+	return ret;
+}
+
+#endif /* __MFD_ALTERA_A10SR_H */
-- 
1.7.9.5