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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /drivers/mfd/ssbi.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'drivers/mfd/ssbi.c')
-rw-r--r--drivers/mfd/ssbi.c326
1 files changed, 326 insertions, 0 deletions
diff --git a/drivers/mfd/ssbi.c b/drivers/mfd/ssbi.c
new file mode 100644
index 000000000..6e7aff6e2
--- /dev/null
+++ b/drivers/mfd/ssbi.c
@@ -0,0 +1,326 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* 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.
+ */
+
+#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/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/ssbi.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 {
+ 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);
+};
+
+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 = dev_get_drvdata(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 = dev_get_drvdata(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 ssbi *ssbi;
+ const char *type;
+
+ ssbi = devm_kzalloc(&pdev->dev, sizeof(*ssbi), GFP_KERNEL);
+ if (!ssbi)
+ return -ENOMEM;
+
+ ssbi->base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
+ 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_DESCRIPTION("Qualcomm Single-wire Serial Bus Interface (SSBI) driver");
+MODULE_LICENSE("GPL v2");
+MODULE_VERSION("1.0");
+MODULE_ALIAS("platform:ssbi");
+MODULE_AUTHOR("Dima Zavin <dima@android.com>");