From: Jean-Francois Bortolotti <jeff@xxxxxxxx>
The connected PMU contains several useful nvmem cells such as RTC offset,
boot failure counters, reboot/shutdown selector, and a few others.
In addition M3+ machines have their USB-PD controller connected via SPMI.
Signed-off-by: Jean-Francois Bortolotti <jeff@xxxxxxxx>
Co-developed-by: Sasha Finkelstein <fnkl.kernel@xxxxxxxxx>
Signed-off-by: Sasha Finkelstein <fnkl.kernel@xxxxxxxxx>
---
MAINTAINERS | 1 +
drivers/spmi/Kconfig | 8 ++
drivers/spmi/Makefile | 1 +
drivers/spmi/spmi-apple-controller.c | 178 +++++++++++++++++++++++++++++++++++
4 files changed, 188 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 271ff8110df83c2d4fe7fbbfffc0a72259460bc5..9006695261d29fbc1e15659c2b43d7afeee0b656 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2254,6 +2254,7 @@ F: drivers/nvmem/apple-efuses.c
F: drivers/pinctrl/pinctrl-apple-gpio.c
F: drivers/pwm/pwm-apple.c
F: drivers/soc/apple/*
+F: drivers/spmi/spmi-apple-controller.c
F: drivers/watchdog/apple_wdt.c
F: include/dt-bindings/interrupt-controller/apple-aic.h
F: include/dt-bindings/pinctrl/apple.h
diff --git a/drivers/spmi/Kconfig b/drivers/spmi/Kconfig
index 73780204631463631cabcbad5bf83e8dbbee94ce..9005fa91d9f4e541403ccc7bf84e0592402ac41e 100644
--- a/drivers/spmi/Kconfig
+++ b/drivers/spmi/Kconfig
@@ -11,6 +11,14 @@ menuconfig SPMI
if SPMI
+config SPMI_APPLE
+ tristate "Apple SoC SPMI Controller platform driver"
+ depends on ARCH_APPLE || COMPILE_TEST
+ help
+ If you say yes to this option, support will be included for the
+ SPMI controller present on many Apple SoCs, including the
+ t8103 (M1) and t600x (M1 Pro/Max).
+
config SPMI_HISI3670
tristate "Hisilicon 3670 SPMI Controller"
select IRQ_DOMAIN_HIERARCHY
diff --git a/drivers/spmi/Makefile b/drivers/spmi/Makefile
index 7f152167bb05b2c24a0f9669f60278152898eebb..38ac635645ba65aa46cb5e8a50072ed9771e229b 100644
--- a/drivers/spmi/Makefile
+++ b/drivers/spmi/Makefile
@@ -4,6 +4,7 @@
#
obj-$(CONFIG_SPMI) += spmi.o spmi-devres.o
+obj-$(CONFIG_SPMI_APPLE) += spmi-apple-controller.o
obj-$(CONFIG_SPMI_HISI3670) += hisi-spmi-controller.o
obj-$(CONFIG_SPMI_MSM_PMIC_ARB) += spmi-pmic-arb.o
obj-$(CONFIG_SPMI_MTK_PMIF) += spmi-mtk-pmif.o
diff --git a/drivers/spmi/spmi-apple-controller.c b/drivers/spmi/spmi-apple-controller.c
new file mode 100644
index 0000000000000000000000000000000000000000..2d4a677aaff6b10fce80f7eacc330605674ea495
--- /dev/null
+++ b/drivers/spmi/spmi-apple-controller.c
@@ -0,0 +1,178 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Apple SoC SPMI device driver
+ *
+ * Copyright The Asahi Linux Contributors
+ *
+ * Inspired by:
+ * OpenBSD support Copyright (c) 2021 Mark Kettenis <kettenis@xxxxxxxxxxx>
+ * Correllium support Copyright (C) 2021 Corellium LLC
+ * hisi-spmi-controller.c
+ * spmi-pmic-arb.c Copyright (c) 2021, The Linux Foundation.
+ */
+
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+#include <linux/spmi.h>
+
+/* SPMI Controller Registers */
+#define SPMI_STATUS_REG 0
+#define SPMI_CMD_REG 0x4
+#define SPMI_RSP_REG 0x8
+
+#define SPMI_RX_FIFO_EMPTY BIT(24)
+
+#define REG_POLL_INTERVAL 10000
+#define REG_POLL_TIMEOUT (REG_POLL_INTERVAL * 5)
+
+struct apple_spmi {
+ void __iomem *regs;
+};
+
+#define poll_reg(spmi, reg, val, cond) \
+ readl_poll_timeout((spmi)->regs + (reg), (val), (cond), \
+ REG_POLL_INTERVAL, REG_POLL_TIMEOUT)
+
+static inline u32 read_reg(struct apple_spmi *spmi, int offset)
+{
+ return readl(spmi->regs + offset);
+}
+
+static inline void write_reg(u32 value, struct apple_spmi *spmi, int offset)
+{
+ writel(value, spmi->regs + offset);
+}
+
+static inline u32 apple_spmi_pack_cmd(u8 opc, u8 sid, u16 saddr, size_t len)
+{
+ return opc | sid << 8 | saddr << 16 | (len - 1) | (1 << 15);
+}
+
+/* Wait for Rx FIFO to have something */
+static int apple_spmi_wait_rx_not_empty(struct spmi_controller *ctrl)
+{
+ struct apple_spmi *spmi = spmi_controller_get_drvdata(ctrl);
+ int ret;
+ u32 status;
+
+ ret = poll_reg(spmi, SPMI_STATUS_REG, status, !(status & SPMI_RX_FIFO_EMPTY));
+ if (ret) {
+ dev_err(&ctrl->dev,
+ "%s: Failed to wait for RX FIFO not empty\n", __func__);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int spmi_read_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid,
+ u16 saddr, u8 *buf, size_t len)
+{
+ struct apple_spmi *spmi = spmi_controller_get_drvdata(ctrl);
+ u32 spmi_cmd = apple_spmi_pack_cmd(opc, sid, saddr, len);
+ u32 rsp;
+ size_t len_read = 0;
+ u8 i;
+ int ret;
+
+ write_reg(spmi_cmd, spmi, SPMI_CMD_REG);
+
+ ret = apple_spmi_wait_rx_not_empty(ctrl);
+ if (ret)
+ return ret;
+
+ /* Discard SPMI reply status */
+ read_reg(spmi, SPMI_RSP_REG);
+
+ /* Read SPMI data reply */
+ while (len_read < len) {
+ rsp = read_reg(spmi, SPMI_RSP_REG);
+ i = 0;
+ while ((len_read < len) && (i < 4)) {
+ buf[len_read++] = ((0xff << (8 * i)) & rsp) >> (8 * i);
+ i += 1;
+ }
+ }
+
+ return 0;
+}
+
+static int spmi_write_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid,
+ u16 saddr, const u8 *buf, size_t len)
+{
+ struct apple_spmi *spmi = spmi_controller_get_drvdata(ctrl);
+ u32 spmi_cmd = apple_spmi_pack_cmd(opc, sid, saddr, len);
+ size_t i = 0, j;
+ int ret;
+
+ write_reg(spmi_cmd, spmi, SPMI_CMD_REG);
+
+ while (i < len) {
+ j = 0;
+ spmi_cmd = 0;
+ while ((j < 4) & (i < len))
+ spmi_cmd |= buf[i++] << (j++ * 8);
+
+ write_reg(spmi_cmd, spmi, SPMI_CMD_REG);
+ }
+
+ ret = apple_spmi_wait_rx_not_empty(ctrl);
+ if (ret)
+ return ret;
+
+ /* Discard */
+ read_reg(spmi, SPMI_RSP_REG);
+
+ return 0;
+}
+
+static int apple_spmi_probe(struct platform_device *pdev)
+{
+ struct apple_spmi *spmi;
+ struct spmi_controller *ctrl;
+ int ret;
+
+ ctrl = devm_spmi_controller_alloc(&pdev->dev, sizeof(*spmi));
+ if (IS_ERR(ctrl))
+ return -ENOMEM;
+
+ spmi = spmi_controller_get_drvdata(ctrl);
+
+ spmi->regs = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(spmi->regs))
+ return PTR_ERR(spmi->regs);
+
+ ctrl->dev.of_node = pdev->dev.of_node;
+
+ ctrl->read_cmd = spmi_read_cmd;
+ ctrl->write_cmd = spmi_write_cmd;
+
+ ret = devm_spmi_controller_add(&pdev->dev, ctrl);
+ if (ret)
+ return dev_err_probe(&pdev->dev, ret,
+ "spmi_controller_add failed\n");
+
+ return 0;
+}
+
+static const struct of_device_id apple_spmi_match_table[] = {
+ { .compatible = "apple,spmi", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, apple_spmi_match_table);
+
+static struct platform_driver apple_spmi_driver = {
+ .probe = apple_spmi_probe,
+ .driver = {
+ .name = "apple-spmi",
+ .of_match_table = apple_spmi_match_table,
+ },
+};
+module_platform_driver(apple_spmi_driver);
+
+MODULE_AUTHOR("Jean-Francois Bortolotti <jeff@xxxxxxxx>");
+MODULE_DESCRIPTION("Apple SoC SPMI driver");
+MODULE_LICENSE("GPL");
--
2.48.1
