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-rw-r--r--drivers/mfd/ssbi.c338
1 files changed, 338 insertions, 0 deletions
diff --git a/drivers/mfd/ssbi.c b/drivers/mfd/ssbi.c
new file mode 100644
index 000000000..36b96fee4
--- /dev/null
+++ b/drivers/mfd/ssbi.c
@@ -0,0 +1,338 @@
+/* Copyright (c) 2009-2013, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2010, Google Inc.
+ *
+ * Original authors: Code Aurora Forum
+ *
+ * Author: Dima Zavin <dima@android.com>
+ * - Largely rewritten from original to not be an i2c driver.
+ *
+ * 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.
+ */
+
+#define pr_fmt(fmt) "%s: " fmt, __func__
+
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/ssbi.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+
+/* SSBI 2.0 controller registers */
+#define SSBI2_CMD 0x0008
+#define SSBI2_RD 0x0010
+#define SSBI2_STATUS 0x0014
+#define SSBI2_MODE2 0x001C
+
+/* SSBI_CMD fields */
+#define SSBI_CMD_RDWRN (1 << 24)
+
+/* SSBI_STATUS fields */
+#define SSBI_STATUS_RD_READY (1 << 2)
+#define SSBI_STATUS_READY (1 << 1)
+#define SSBI_STATUS_MCHN_BUSY (1 << 0)
+
+/* SSBI_MODE2 fields */
+#define SSBI_MODE2_REG_ADDR_15_8_SHFT 0x04
+#define SSBI_MODE2_REG_ADDR_15_8_MASK (0x7f << SSBI_MODE2_REG_ADDR_15_8_SHFT)
+
+#define SET_SSBI_MODE2_REG_ADDR_15_8(MD, AD) \
+ (((MD) & 0x0F) | ((((AD) >> 8) << SSBI_MODE2_REG_ADDR_15_8_SHFT) & \
+ SSBI_MODE2_REG_ADDR_15_8_MASK))
+
+/* SSBI PMIC Arbiter command registers */
+#define SSBI_PA_CMD 0x0000
+#define SSBI_PA_RD_STATUS 0x0004
+
+/* SSBI_PA_CMD fields */
+#define SSBI_PA_CMD_RDWRN (1 << 24)
+#define SSBI_PA_CMD_ADDR_MASK 0x7fff /* REG_ADDR_7_0, REG_ADDR_8_14*/
+
+/* SSBI_PA_RD_STATUS fields */
+#define SSBI_PA_RD_STATUS_TRANS_DONE (1 << 27)
+#define SSBI_PA_RD_STATUS_TRANS_DENIED (1 << 26)
+
+#define SSBI_TIMEOUT_US 100
+
+enum ssbi_controller_type {
+ MSM_SBI_CTRL_SSBI = 0,
+ MSM_SBI_CTRL_SSBI2,
+ MSM_SBI_CTRL_PMIC_ARBITER,
+};
+
+struct ssbi {
+ struct device *slave;
+ void __iomem *base;
+ spinlock_t lock;
+ enum ssbi_controller_type controller_type;
+ int (*read)(struct ssbi *, u16 addr, u8 *buf, int len);
+ int (*write)(struct ssbi *, u16 addr, const u8 *buf, int len);
+};
+
+#define to_ssbi(dev) platform_get_drvdata(to_platform_device(dev))
+
+static inline u32 ssbi_readl(struct ssbi *ssbi, u32 reg)
+{
+ return readl(ssbi->base + reg);
+}
+
+static inline void ssbi_writel(struct ssbi *ssbi, u32 val, u32 reg)
+{
+ writel(val, ssbi->base + reg);
+}
+
+/*
+ * Via private exchange with one of the original authors, the hardware
+ * should generally finish a transaction in about 5us. The worst
+ * case, is when using the arbiter and both other CPUs have just
+ * started trying to use the SSBI bus will result in a time of about
+ * 20us. It should never take longer than this.
+ *
+ * As such, this wait merely spins, with a udelay.
+ */
+static int ssbi_wait_mask(struct ssbi *ssbi, u32 set_mask, u32 clr_mask)
+{
+ u32 timeout = SSBI_TIMEOUT_US;
+ u32 val;
+
+ while (timeout--) {
+ val = ssbi_readl(ssbi, SSBI2_STATUS);
+ if (((val & set_mask) == set_mask) && ((val & clr_mask) == 0))
+ return 0;
+ udelay(1);
+ }
+
+ return -ETIMEDOUT;
+}
+
+static int
+ssbi_read_bytes(struct ssbi *ssbi, u16 addr, u8 *buf, int len)
+{
+ u32 cmd = SSBI_CMD_RDWRN | ((addr & 0xff) << 16);
+ int ret = 0;
+
+ if (ssbi->controller_type == MSM_SBI_CTRL_SSBI2) {
+ u32 mode2 = ssbi_readl(ssbi, SSBI2_MODE2);
+ mode2 = SET_SSBI_MODE2_REG_ADDR_15_8(mode2, addr);
+ ssbi_writel(ssbi, mode2, SSBI2_MODE2);
+ }
+
+ while (len) {
+ ret = ssbi_wait_mask(ssbi, SSBI_STATUS_READY, 0);
+ if (ret)
+ goto err;
+
+ ssbi_writel(ssbi, cmd, SSBI2_CMD);
+ ret = ssbi_wait_mask(ssbi, SSBI_STATUS_RD_READY, 0);
+ if (ret)
+ goto err;
+ *buf++ = ssbi_readl(ssbi, SSBI2_RD) & 0xff;
+ len--;
+ }
+
+err:
+ return ret;
+}
+
+static int
+ssbi_write_bytes(struct ssbi *ssbi, u16 addr, const u8 *buf, int len)
+{
+ int ret = 0;
+
+ if (ssbi->controller_type == MSM_SBI_CTRL_SSBI2) {
+ u32 mode2 = ssbi_readl(ssbi, SSBI2_MODE2);
+ mode2 = SET_SSBI_MODE2_REG_ADDR_15_8(mode2, addr);
+ ssbi_writel(ssbi, mode2, SSBI2_MODE2);
+ }
+
+ while (len) {
+ ret = ssbi_wait_mask(ssbi, SSBI_STATUS_READY, 0);
+ if (ret)
+ goto err;
+
+ ssbi_writel(ssbi, ((addr & 0xff) << 16) | *buf, SSBI2_CMD);
+ ret = ssbi_wait_mask(ssbi, 0, SSBI_STATUS_MCHN_BUSY);
+ if (ret)
+ goto err;
+ buf++;
+ len--;
+ }
+
+err:
+ return ret;
+}
+
+/*
+ * See ssbi_wait_mask for an explanation of the time and the
+ * busywait.
+ */
+static inline int
+ssbi_pa_transfer(struct ssbi *ssbi, u32 cmd, u8 *data)
+{
+ u32 timeout = SSBI_TIMEOUT_US;
+ u32 rd_status = 0;
+
+ ssbi_writel(ssbi, cmd, SSBI_PA_CMD);
+
+ while (timeout--) {
+ rd_status = ssbi_readl(ssbi, SSBI_PA_RD_STATUS);
+
+ if (rd_status & SSBI_PA_RD_STATUS_TRANS_DENIED)
+ return -EPERM;
+
+ if (rd_status & SSBI_PA_RD_STATUS_TRANS_DONE) {
+ if (data)
+ *data = rd_status & 0xff;
+ return 0;
+ }
+ udelay(1);
+ }
+
+ return -ETIMEDOUT;
+}
+
+static int
+ssbi_pa_read_bytes(struct ssbi *ssbi, u16 addr, u8 *buf, int len)
+{
+ u32 cmd;
+ int ret = 0;
+
+ cmd = SSBI_PA_CMD_RDWRN | (addr & SSBI_PA_CMD_ADDR_MASK) << 8;
+
+ while (len) {
+ ret = ssbi_pa_transfer(ssbi, cmd, buf);
+ if (ret)
+ goto err;
+ buf++;
+ len--;
+ }
+
+err:
+ return ret;
+}
+
+static int
+ssbi_pa_write_bytes(struct ssbi *ssbi, u16 addr, const u8 *buf, int len)
+{
+ u32 cmd;
+ int ret = 0;
+
+ while (len) {
+ cmd = (addr & SSBI_PA_CMD_ADDR_MASK) << 8 | *buf;
+ ret = ssbi_pa_transfer(ssbi, cmd, NULL);
+ if (ret)
+ goto err;
+ buf++;
+ len--;
+ }
+
+err:
+ return ret;
+}
+
+int ssbi_read(struct device *dev, u16 addr, u8 *buf, int len)
+{
+ struct ssbi *ssbi = to_ssbi(dev);
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(&ssbi->lock, flags);
+ ret = ssbi->read(ssbi, addr, buf, len);
+ spin_unlock_irqrestore(&ssbi->lock, flags);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(ssbi_read);
+
+int ssbi_write(struct device *dev, u16 addr, const u8 *buf, int len)
+{
+ struct ssbi *ssbi = to_ssbi(dev);
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(&ssbi->lock, flags);
+ ret = ssbi->write(ssbi, addr, buf, len);
+ spin_unlock_irqrestore(&ssbi->lock, flags);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(ssbi_write);
+
+static int ssbi_probe(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct resource *mem_res;
+ struct ssbi *ssbi;
+ const char *type;
+
+ ssbi = devm_kzalloc(&pdev->dev, sizeof(*ssbi), GFP_KERNEL);
+ if (!ssbi)
+ return -ENOMEM;
+
+ mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ ssbi->base = devm_ioremap_resource(&pdev->dev, mem_res);
+ if (IS_ERR(ssbi->base))
+ return PTR_ERR(ssbi->base);
+
+ platform_set_drvdata(pdev, ssbi);
+
+ type = of_get_property(np, "qcom,controller-type", NULL);
+ if (type == NULL) {
+ dev_err(&pdev->dev, "Missing qcom,controller-type property\n");
+ return -EINVAL;
+ }
+ dev_info(&pdev->dev, "SSBI controller type: '%s'\n", type);
+ if (strcmp(type, "ssbi") == 0)
+ ssbi->controller_type = MSM_SBI_CTRL_SSBI;
+ else if (strcmp(type, "ssbi2") == 0)
+ ssbi->controller_type = MSM_SBI_CTRL_SSBI2;
+ else if (strcmp(type, "pmic-arbiter") == 0)
+ ssbi->controller_type = MSM_SBI_CTRL_PMIC_ARBITER;
+ else {
+ dev_err(&pdev->dev, "Unknown qcom,controller-type\n");
+ return -EINVAL;
+ }
+
+ if (ssbi->controller_type == MSM_SBI_CTRL_PMIC_ARBITER) {
+ ssbi->read = ssbi_pa_read_bytes;
+ ssbi->write = ssbi_pa_write_bytes;
+ } else {
+ ssbi->read = ssbi_read_bytes;
+ ssbi->write = ssbi_write_bytes;
+ }
+
+ spin_lock_init(&ssbi->lock);
+
+ return devm_of_platform_populate(&pdev->dev);
+}
+
+static const struct of_device_id ssbi_match_table[] = {
+ { .compatible = "qcom,ssbi" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, ssbi_match_table);
+
+static struct platform_driver ssbi_driver = {
+ .probe = ssbi_probe,
+ .driver = {
+ .name = "ssbi",
+ .of_match_table = ssbi_match_table,
+ },
+};
+module_platform_driver(ssbi_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_VERSION("1.0");
+MODULE_ALIAS("platform:ssbi");
+MODULE_AUTHOR("Dima Zavin <dima@android.com>");
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-24 13:35:12 +0000