spmi: Add MSM PMIC Arbiter SPMI controller

Qualcomm's PMIC Arbiter SPMI controller functions as a bus master and
is used to communication with one or more PMIC (slave) devices on the
SPMI bus.  The PMIC Arbiter is actually a hardware wrapper around the
SPMI controller that provides concurrent and autonomous PMIC access
to various entities that need to communicate with the PMIC.

The SPMI controller hardware handles all of the SPMI bus activity (bus
arbitration, sequence start condition, transmission of frames, etc).
This software driver uses the PMIC Arbiter register interface to
initiate command sequences on the SPMI bus.  The status register is
read to determine when the command sequence has completed and whether
or not it completed successfully.

Signed-off-by: Kenneth Heitke <kheitke@codeaurora.org>
Signed-off-by: Josh Cartwright <joshc@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 424 insertions, 0 deletions

diff --git a/drivers/spmi/Kconfig b/drivers/spmi/Kconfig
index 1dbfee022e90..80b79013fd1e 100644
--- a/drivers/spmi/Kconfig
+++ b/drivers/spmi/Kconfig
@@ -7,3 +7,20 @@ menuconfig SPMI
           SPMI (System Power Management Interface) is a two-wire
           serial interface between baseband and application processors
           and Power Management Integrated Circuits (PMIC).
+
+if SPMI
+
+config SPMI_MSM_PMIC_ARB
+        tristate "Qualcomm MSM SPMI Controller (PMIC Arbiter)"
+        depends on ARM
+        depends on ARCH_MSM || COMPILE_TEST
+        default ARCH_MSM
+        help
+          If you say yes to this option, support will be included for the
+          built-in SPMI PMIC Arbiter interface on Qualcomm MSM family
+          processors.
+
+          This is required for communicating with Qualcomm PMICs and
+          other devices that have the SPMI interface.
+
+endif
diff --git a/drivers/spmi/Makefile b/drivers/spmi/Makefile
index 1de1acd6a587..fc75104a5aab 100644
--- a/drivers/spmi/Makefile
+++ b/drivers/spmi/Makefile
@@ -2,3 +2,5 @@
 # Makefile for kernel SPMI framework.
 #
 obj-$(CONFIG_SPMI)      += spmi.o
+
+obj-$(CONFIG_SPMI_MSM_PMIC_ARB) += spmi-pmic-arb.o
diff --git a/drivers/spmi/spmi-pmic-arb.c b/drivers/spmi/spmi-pmic-arb.c
new file mode 100644
index 000000000000..2dd27e8d140d
--- /dev/null
+++ b/drivers/spmi/spmi-pmic-arb.c
@@ -0,0 +1,405 @@
+/* Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only 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.
+ */
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spmi.h>
+
+/* PMIC Arbiter configuration registers */
+#define PMIC_ARB_VERSION                0x0000
+#define PMIC_ARB_INT_EN                 0x0004
+
+/* PMIC Arbiter channel registers */
+#define PMIC_ARB_CMD(N)                 (0x0800 + (0x80 * (N)))
+#define PMIC_ARB_CONFIG(N)              (0x0804 + (0x80 * (N)))
+#define PMIC_ARB_STATUS(N)              (0x0808 + (0x80 * (N)))
+#define PMIC_ARB_WDATA0(N)              (0x0810 + (0x80 * (N)))
+#define PMIC_ARB_WDATA1(N)              (0x0814 + (0x80 * (N)))
+#define PMIC_ARB_RDATA0(N)              (0x0818 + (0x80 * (N)))
+#define PMIC_ARB_RDATA1(N)              (0x081C + (0x80 * (N)))
+
+/* Interrupt Controller */
+#define SPMI_PIC_OWNER_ACC_STATUS(M, N) (0x0000 + ((32 * (M)) + (4 * (N))))
+#define SPMI_PIC_ACC_ENABLE(N)          (0x0200 + (4 * (N)))
+#define SPMI_PIC_IRQ_STATUS(N)          (0x0600 + (4 * (N)))
+#define SPMI_PIC_IRQ_CLEAR(N)           (0x0A00 + (4 * (N)))
+
+/* Mapping Table */
+#define SPMI_MAPPING_TABLE_REG(N)       (0x0B00 + (4 * (N)))
+#define SPMI_MAPPING_BIT_INDEX(X)       (((X) >> 18) & 0xF)
+#define SPMI_MAPPING_BIT_IS_0_FLAG(X)   (((X) >> 17) & 0x1)
+#define SPMI_MAPPING_BIT_IS_0_RESULT(X) (((X) >> 9) & 0xFF)
+#define SPMI_MAPPING_BIT_IS_1_FLAG(X)   (((X) >> 8) & 0x1)
+#define SPMI_MAPPING_BIT_IS_1_RESULT(X) (((X) >> 0) & 0xFF)
+
+#define SPMI_MAPPING_TABLE_LEN          255
+#define SPMI_MAPPING_TABLE_TREE_DEPTH   16      /* Maximum of 16-bits */
+
+/* Ownership Table */
+#define SPMI_OWNERSHIP_TABLE_REG(N)     (0x0700 + (4 * (N)))
+#define SPMI_OWNERSHIP_PERIPH2OWNER(X)  ((X) & 0x7)
+
+/* Channel Status fields */
+enum pmic_arb_chnl_status {
+        PMIC_ARB_STATUS_DONE    = (1 << 0),
+        PMIC_ARB_STATUS_FAILURE = (1 << 1),
+        PMIC_ARB_STATUS_DENIED  = (1 << 2),
+        PMIC_ARB_STATUS_DROPPED = (1 << 3),
+};
+
+/* Command register fields */
+#define PMIC_ARB_CMD_MAX_BYTE_COUNT     8
+
+/* Command Opcodes */
+enum pmic_arb_cmd_op_code {
+        PMIC_ARB_OP_EXT_WRITEL = 0,
+        PMIC_ARB_OP_EXT_READL = 1,
+        PMIC_ARB_OP_EXT_WRITE = 2,
+        PMIC_ARB_OP_RESET = 3,
+        PMIC_ARB_OP_SLEEP = 4,
+        PMIC_ARB_OP_SHUTDOWN = 5,
+        PMIC_ARB_OP_WAKEUP = 6,
+        PMIC_ARB_OP_AUTHENTICATE = 7,
+        PMIC_ARB_OP_MSTR_READ = 8,
+        PMIC_ARB_OP_MSTR_WRITE = 9,
+        PMIC_ARB_OP_EXT_READ = 13,
+        PMIC_ARB_OP_WRITE = 14,
+        PMIC_ARB_OP_READ = 15,
+        PMIC_ARB_OP_ZERO_WRITE = 16,
+};
+
+/* Maximum number of support PMIC peripherals */
+#define PMIC_ARB_MAX_PERIPHS            256
+#define PMIC_ARB_PERIPH_ID_VALID        (1 << 15)
+#define PMIC_ARB_TIMEOUT_US             100
+#define PMIC_ARB_MAX_TRANS_BYTES        (8)
+
+#define PMIC_ARB_APID_MASK              0xFF
+#define PMIC_ARB_PPID_MASK              0xFFF
+
+/* interrupt enable bit */
+#define SPMI_PIC_ACC_ENABLE_BIT         BIT(0)
+
+/**
+ * spmi_pmic_arb_dev - SPMI PMIC Arbiter object
+ *
+ * @base:               address of the PMIC Arbiter core registers.
+ * @intr:               address of the SPMI interrupt control registers.
+ * @cnfg:               address of the PMIC Arbiter configuration registers.
+ * @lock:               lock to synchronize accesses.
+ * @channel:            which channel to use for accesses.
+ */
+struct spmi_pmic_arb_dev {
+        void __iomem            *base;
+        void __iomem            *intr;
+        void __iomem            *cnfg;
+        raw_spinlock_t          lock;
+        u8                      channel;
+};
+
+static inline u32 pmic_arb_base_read(struct spmi_pmic_arb_dev *dev, u32 offset)
+{
+        return readl_relaxed(dev->base + offset);
+}
+
+static inline void pmic_arb_base_write(struct spmi_pmic_arb_dev *dev,
+                                       u32 offset, u32 val)
+{
+        writel_relaxed(val, dev->base + offset);
+}
+
+/**
+ * pa_read_data: reads pmic-arb's register and copy 1..4 bytes to buf
+ * @bc:         byte count -1. range: 0..3
+ * @reg:        register's address
+ * @buf:        output parameter, length must be bc + 1
+ */
+static void pa_read_data(struct spmi_pmic_arb_dev *dev, u8 *buf, u32 reg, u8 bc)
+{
+        u32 data = pmic_arb_base_read(dev, reg);
+        memcpy(buf, &data, (bc & 3) + 1);
+}
+
+/**
+ * pa_write_data: write 1..4 bytes from buf to pmic-arb's register
+ * @bc:         byte-count -1. range: 0..3.
+ * @reg:        register's address.
+ * @buf:        buffer to write. length must be bc + 1.
+ */
+static void
+pa_write_data(struct spmi_pmic_arb_dev *dev, const u8 *buf, u32 reg, u8 bc)
+{
+        u32 data = 0;
+        memcpy(&data, buf, (bc & 3) + 1);
+        pmic_arb_base_write(dev, reg, data);
+}
+
+static int pmic_arb_wait_for_done(struct spmi_controller *ctrl)
+{
+        struct spmi_pmic_arb_dev *dev = spmi_controller_get_drvdata(ctrl);
+        u32 status = 0;
+        u32 timeout = PMIC_ARB_TIMEOUT_US;
+        u32 offset = PMIC_ARB_STATUS(dev->channel);
+
+        while (timeout--) {
+                status = pmic_arb_base_read(dev, offset);
+
+                if (status & PMIC_ARB_STATUS_DONE) {
+                        if (status & PMIC_ARB_STATUS_DENIED) {
+                                dev_err(&ctrl->dev,
+                                        "%s: transaction denied (0x%x)\n",
+                                        __func__, status);
+                                return -EPERM;
+                        }
+
+                        if (status & PMIC_ARB_STATUS_FAILURE) {
+                                dev_err(&ctrl->dev,
+                                        "%s: transaction failed (0x%x)\n",
+                                        __func__, status);
+                                return -EIO;
+                        }
+
+                        if (status & PMIC_ARB_STATUS_DROPPED) {
+                                dev_err(&ctrl->dev,
+                                        "%s: transaction dropped (0x%x)\n",
+                                        __func__, status);
+                                return -EIO;
+                        }
+
+                        return 0;
+                }
+                udelay(1);
+        }
+
+        dev_err(&ctrl->dev,
+                "%s: timeout, status 0x%x\n",
+                __func__, status);
+        return -ETIMEDOUT;
+}
+
+/* Non-data command */
+static int pmic_arb_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid)
+{
+        struct spmi_pmic_arb_dev *pmic_arb = spmi_controller_get_drvdata(ctrl);
+        unsigned long flags;
+        u32 cmd;
+        int rc;
+
+        /* Check for valid non-data command */
+        if (opc < SPMI_CMD_RESET || opc > SPMI_CMD_WAKEUP)
+                return -EINVAL;
+
+        cmd = ((opc | 0x40) << 27) | ((sid & 0xf) << 20);
+
+        raw_spin_lock_irqsave(&pmic_arb->lock, flags);
+        pmic_arb_base_write(pmic_arb, PMIC_ARB_CMD(pmic_arb->channel), cmd);
+        rc = pmic_arb_wait_for_done(ctrl);
+        raw_spin_unlock_irqrestore(&pmic_arb->lock, flags);
+
+        return rc;
+}
+
+static int pmic_arb_read_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid,
+                             u16 addr, u8 *buf, size_t len)
+{
+        struct spmi_pmic_arb_dev *pmic_arb = spmi_controller_get_drvdata(ctrl);
+        unsigned long flags;
+        u8 bc = len - 1;
+        u32 cmd;
+        int rc;
+
+        if (bc >= PMIC_ARB_MAX_TRANS_BYTES) {
+                dev_err(&ctrl->dev,
+                        "pmic-arb supports 1..%d bytes per trans, but %d requested",
+                        PMIC_ARB_MAX_TRANS_BYTES, len);
+                return  -EINVAL;
+        }
+
+        /* Check the opcode */
+        if (opc >= 0x60 && opc <= 0x7F)
+                opc = PMIC_ARB_OP_READ;
+        else if (opc >= 0x20 && opc <= 0x2F)
+                opc = PMIC_ARB_OP_EXT_READ;
+        else if (opc >= 0x38 && opc <= 0x3F)
+                opc = PMIC_ARB_OP_EXT_READL;
+        else
+                return -EINVAL;
+
+        cmd = (opc << 27) | ((sid & 0xf) << 20) | (addr << 4) | (bc & 0x7);
+
+        raw_spin_lock_irqsave(&pmic_arb->lock, flags);
+        pmic_arb_base_write(pmic_arb, PMIC_ARB_CMD(pmic_arb->channel), cmd);
+        rc = pmic_arb_wait_for_done(ctrl);
+        if (rc)
+                goto done;
+
+        pa_read_data(pmic_arb, buf, PMIC_ARB_RDATA0(pmic_arb->channel),
+                     min_t(u8, bc, 3));
+
+        if (bc > 3)
+                pa_read_data(pmic_arb, buf + 4,
+                                PMIC_ARB_RDATA1(pmic_arb->channel), bc - 4);
+
+done:
+        raw_spin_unlock_irqrestore(&pmic_arb->lock, flags);
+        return rc;
+}
+
+static int pmic_arb_write_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid,
+                              u16 addr, const u8 *buf, size_t len)
+{
+        struct spmi_pmic_arb_dev *pmic_arb = spmi_controller_get_drvdata(ctrl);
+        unsigned long flags;
+        u8 bc = len - 1;
+        u32 cmd;
+        int rc;
+
+        if (bc >= PMIC_ARB_MAX_TRANS_BYTES) {
+                dev_err(&ctrl->dev,
+                        "pmic-arb supports 1..%d bytes per trans, but:%d requested",
+                        PMIC_ARB_MAX_TRANS_BYTES, len);
+                return  -EINVAL;
+        }
+
+        /* Check the opcode */
+        if (opc >= 0x40 && opc <= 0x5F)
+                opc = PMIC_ARB_OP_WRITE;
+        else if (opc >= 0x00 && opc <= 0x0F)
+                opc = PMIC_ARB_OP_EXT_WRITE;
+        else if (opc >= 0x30 && opc <= 0x37)
+                opc = PMIC_ARB_OP_EXT_WRITEL;
+        else if (opc >= 0x80 && opc <= 0xFF)
+                opc = PMIC_ARB_OP_ZERO_WRITE;
+        else
+                return -EINVAL;
+
+        cmd = (opc << 27) | ((sid & 0xf) << 20) | (addr << 4) | (bc & 0x7);
+
+        /* Write data to FIFOs */
+        raw_spin_lock_irqsave(&pmic_arb->lock, flags);
+        pa_write_data(pmic_arb, buf, PMIC_ARB_WDATA0(pmic_arb->channel)
+                                                        , min_t(u8, bc, 3));
+        if (bc > 3)
+                pa_write_data(pmic_arb, buf + 4,
+                                PMIC_ARB_WDATA1(pmic_arb->channel), bc - 4);
+
+        /* Start the transaction */
+        pmic_arb_base_write(pmic_arb, PMIC_ARB_CMD(pmic_arb->channel), cmd);
+        rc = pmic_arb_wait_for_done(ctrl);
+        raw_spin_unlock_irqrestore(&pmic_arb->lock, flags);
+
+        return rc;
+}
+
+static int spmi_pmic_arb_probe(struct platform_device *pdev)
+{
+        struct spmi_pmic_arb_dev *pa;
+        struct spmi_controller *ctrl;
+        struct resource *res;
+        u32 channel;
+        int err, i;
+
+        ctrl = spmi_controller_alloc(&pdev->dev, sizeof(*pa));
+        if (!ctrl)
+                return -ENOMEM;
+
+        pa = spmi_controller_get_drvdata(ctrl);
+
+        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "core");
+        pa->base = devm_ioremap_resource(&ctrl->dev, res);
+        if (IS_ERR(pa->base)) {
+                err = PTR_ERR(pa->base);
+                goto err_put_ctrl;
+        }
+
+        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "intr");
+        pa->intr = devm_ioremap_resource(&ctrl->dev, res);
+        if (IS_ERR(pa->intr)) {
+                err = PTR_ERR(pa->intr);
+                goto err_put_ctrl;
+        }
+
+        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cnfg");
+        pa->cnfg = devm_ioremap_resource(&ctrl->dev, res);
+        if (IS_ERR(pa->cnfg)) {
+                err = PTR_ERR(pa->cnfg);
+                goto err_put_ctrl;
+        }
+
+        err = of_property_read_u32(pdev->dev.of_node, "qcom,channel", &channel);
+        if (err) {
+                dev_err(&pdev->dev, "channel unspecified.\n");
+                goto err_put_ctrl;
+        }
+
+        if (channel > 5) {
+                dev_err(&pdev->dev, "invalid channel (%u) specified.\n",
+                        channel);
+                goto err_put_ctrl;
+        }
+
+        pa->channel = channel;
+
+        platform_set_drvdata(pdev, ctrl);
+        raw_spin_lock_init(&pa->lock);
+
+        ctrl->cmd = pmic_arb_cmd;
+        ctrl->read_cmd = pmic_arb_read_cmd;
+        ctrl->write_cmd = pmic_arb_write_cmd;
+
+        err = spmi_controller_add(ctrl);
+        if (err)
+                goto err_put_ctrl;
+
+        dev_dbg(&ctrl->dev, "PMIC Arb Version 0x%x\n",
+                pmic_arb_base_read(pa, PMIC_ARB_VERSION));
+
+        return 0;
+
+err_put_ctrl:
+        spmi_controller_put(ctrl);
+        return err;
+}
+
+static int spmi_pmic_arb_remove(struct platform_device *pdev)
+{
+        struct spmi_controller *ctrl = platform_get_drvdata(pdev);
+        spmi_controller_remove(ctrl);
+        spmi_controller_put(ctrl);
+        return 0;
+}
+
+static const struct of_device_id spmi_pmic_arb_match_table[] = {
+        { .compatible = "qcom,spmi-pmic-arb", },
+        {},
+};
+MODULE_DEVICE_TABLE(of, spmi_pmic_arb_match_table);
+
+static struct platform_driver spmi_pmic_arb_driver = {
+        .probe          = spmi_pmic_arb_probe,
+        .remove         = spmi_pmic_arb_remove,
+        .driver         = {
+                .name   = "spmi_pmic_arb",
+                .owner  = THIS_MODULE,
+                .of_match_table = spmi_pmic_arb_match_table,
+        },
+};
+module_platform_driver(spmi_pmic_arb_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:spmi_pmic_arb");