| Message ID | 20250305-spmi-v1-2-c98f561fa99f@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Driver for Apple SPMI controller | expand |
Quoting Sasha Finkelstein via B4 Relay (2025-03-05 12:26:40) > From: Jean-Francois Bortolotti <jeff@borto.fr> > Please write some commit text explaining why this driver is important to review. Maybe it's necessary for something to work? > diff --git a/drivers/spmi/spmi-apple-controller.c b/drivers/spmi/spmi-apple-controller.c > new file mode 100644 > index 0000000000000000000000000000000000000000..194fa5dd7c2c6fc4ecfbee0db7930b0c73b02550 > --- /dev/null > +++ b/drivers/spmi/spmi-apple-controller.c > @@ -0,0 +1,176 @@ > +// 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@openbsd.org> > + * Correllium support Copyright (C) 2021 Corellium LLC > + * hisi-spmi-controller.c > + * spmi-pmic-ard.c Copyright (c) 2021, The Linux Foundation. spmi-pmic-arb? > + */ > + > +#include <linux/io.h> > +#include <linux/iopoll.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/of_platform.h> Are these includes used? I think you need 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_relaxed_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_relaxed(spmi->regs + offset); > +} > + > +static inline void write_reg(u32 value, struct apple_spmi *spmi, int offset) > +{ > + writel_relaxed(value, spmi->regs + offset); > +} I'm not a huge fan of these wrappers but OK. Why relaxed accessors? > + > +static int spmi_read_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid, > + u16 saddr, u8 *__buf, size_t bc) Drop the underscore because the variable 'buf' is never used. > +{ > + struct apple_spmi *spmi = spmi_controller_get_drvdata(ctrl); > + u32 spmi_cmd = opc | sid << 8 | saddr << 16 | (bc - 1) | (1 << 15); Can this be some function like apple_spmi_pack_cmd()? I suspect 'bc' is byte_count? Usually we just call that 'len'. > + u32 rsp; > + u32 status; > + size_t len_to_read = 0; len_to_read would imply that it is non-zero to start. Maybe 'len_read' past tense, or decrement 'bc'. > + u8 i; > + int ret; > + > + write_reg(spmi_cmd, spmi, SPMI_CMD_REG); > + > + /* Wait for Rx FIFO to have something */ > + 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; > + } This chunk is the same. Maybe have apple_spmi_wait_for_rx_fifo() that does everything including the error message? > + > + /* Discard SPMI reply status */ > + read_reg(spmi, SPMI_RSP_REG); > + > + /* Read SPMI data reply */ > + while (len_to_read < bc) { > + rsp = read_reg(spmi, SPMI_RSP_REG); > + i = 0; > + while ((len_to_read < bc) && (i < 4)) { > + __buf[len_to_read++] = ((0xff << (8 * i)) & rsp) >> > + (8 * i); > + i += 1; > + } Is this ioread32_rep()? > + } > + > + return 0; > +} > + > +static int spmi_write_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid, > + u16 saddr, const u8 *__buf, size_t bc) > +{ > + struct apple_spmi *spmi = spmi_controller_get_drvdata(ctrl); > + u32 spmi_cmd = opc | sid << 8 | saddr << 16 | (bc - 1) | (1 << 15); > + u32 status; > + size_t i = 0, j; > + int ret; > + > + write_reg(spmi_cmd, spmi, SPMI_CMD_REG); > + > + while (i < bc) { > + j = 0; > + spmi_cmd = 0; > + while ((j < 4) & (i < bc)) > + spmi_cmd |= __buf[i++] << (j++ * 8); Is this iowrite32_rep()? Perhaps unaligned sizes have to be dealt with, but otherwise I suspect it would be more efficient to use iowrite32_rep() until the number of bytes is less than 4 and then do the one extra pack. > + > + write_reg(spmi_cmd, spmi, SPMI_CMD_REG); > + } > + > + /* Wait for Rx FIFO to have something */ > + 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__); ^ Please put a space after ---| > + return ret; > + } > + > + /* Discard */ > + read_reg(spmi, SPMI_RSP_REG); > + > + return 0; > +} > + > +static int spmi_controller_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)) { > + dev_err_probe(&pdev->dev, PTR_ERR(ctrl), > + "Can't allocate spmi_controller data\n"); This is likely redundant given that the spmi core API prints errors. I could see a patch that moves to dev_err_probe() there. > + return -ENOMEM; > + } > + > + spmi = spmi_controller_get_drvdata(ctrl); > + > + spmi->regs = devm_platform_ioremap_resource(pdev, 0); This already prints an error message so the dev_err_probe() later is redundant. Please remove. > + if (IS_ERR(spmi->regs)) { > + dev_err_probe(&pdev->dev, PTR_ERR(spmi->regs), > + "Can't get ioremap regs\n"); > + return PTR_ERR(spmi->regs); > + } > + > + ctrl->dev.of_node = of_node_get(pdev->dev.of_node); Drop the of_node_get(), especially because it never gets put. > + > + ctrl->read_cmd = spmi_read_cmd; > + ctrl->write_cmd = spmi_write_cmd; > + > + ret = devm_spmi_controller_add(&pdev->dev, ctrl); > + if (ret) { > + dev_err(&pdev->dev, > + "spmi_controller_add failed with error %d!\n", ret); Use 'return dev_err_probe()'? > + return ret; > + } > + > + return 0; > +} > + > +static const struct of_device_id spmi_controller_match_table[] = { > + { .compatible = "apple,spmi", }, > + {} > +}; > +MODULE_DEVICE_TABLE(of, spmi_controller_match_table); > + > +static struct platform_driver spmi_controller_driver = { How about apple_spmi_driver? > + .probe = spmi_controller_probe, And apple_spmi_probe? > + .driver = { > + .name = "apple-spmi", > + .of_match_table = spmi_controller_match_table, And apple_spmi_match_table? > + }, > +}; > +module_platform_driver(spmi_controller_driver);
On Wed, 5 Mar 2025 at 23:11, Stephen Boyd <sboyd@kernel.org> wrote: > > Quoting Sasha Finkelstein via B4 Relay (2025-03-05 12:26:40) > > + while (len_to_read < bc) { > > + rsp = read_reg(spmi, SPMI_RSP_REG); > > + i = 0; > > + while ((len_to_read < bc) && (i < 4)) { > > + __buf[len_to_read++] = ((0xff << (8 * i)) & rsp) >> > > + (8 * i); > > + i += 1; > > + } > > Is this ioread32_rep()? > [...] > > + while (i < bc) { > > + j = 0; > > + spmi_cmd = 0; > > + while ((j < 4) & (i < bc)) > > + spmi_cmd |= __buf[i++] << (j++ * 8); > > Is this iowrite32_rep()? Perhaps unaligned sizes have to be dealt with, > but otherwise I suspect it would be more efficient to use > iowrite32_rep() until the number of bytes is less than 4 and then do the > one extra pack. I think it would be better to leave them open-coded, io{read,write}32_rep casts the buffer to u32 and accesses it that way, probably resulting in unaligned accesses, and we are on arm64.
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..194fa5dd7c2c6fc4ecfbee0db7930b0c73b02550 --- /dev/null +++ b/drivers/spmi/spmi-apple-controller.c @@ -0,0 +1,176 @@ +// 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@openbsd.org> + * Correllium support Copyright (C) 2021 Corellium LLC + * hisi-spmi-controller.c + * spmi-pmic-ard.c Copyright (c) 2021, The Linux Foundation. + */ + +#include <linux/io.h> +#include <linux/iopoll.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_platform.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_relaxed_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_relaxed(spmi->regs + offset); +} + +static inline void write_reg(u32 value, struct apple_spmi *spmi, int offset) +{ + writel_relaxed(value, spmi->regs + offset); +} + +static int spmi_read_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid, + u16 saddr, u8 *__buf, size_t bc) +{ + struct apple_spmi *spmi = spmi_controller_get_drvdata(ctrl); + u32 spmi_cmd = opc | sid << 8 | saddr << 16 | (bc - 1) | (1 << 15); + u32 rsp; + u32 status; + size_t len_to_read = 0; + u8 i; + int ret; + + write_reg(spmi_cmd, spmi, SPMI_CMD_REG); + + /* Wait for Rx FIFO to have something */ + 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; + } + + /* Discard SPMI reply status */ + read_reg(spmi, SPMI_RSP_REG); + + /* Read SPMI data reply */ + while (len_to_read < bc) { + rsp = read_reg(spmi, SPMI_RSP_REG); + i = 0; + while ((len_to_read < bc) && (i < 4)) { + __buf[len_to_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 bc) +{ + struct apple_spmi *spmi = spmi_controller_get_drvdata(ctrl); + u32 spmi_cmd = opc | sid << 8 | saddr << 16 | (bc - 1) | (1 << 15); + u32 status; + size_t i = 0, j; + int ret; + + write_reg(spmi_cmd, spmi, SPMI_CMD_REG); + + while (i < bc) { + j = 0; + spmi_cmd = 0; + while ((j < 4) & (i < bc)) + spmi_cmd |= __buf[i++] << (j++ * 8); + + write_reg(spmi_cmd, spmi, SPMI_CMD_REG); + } + + /* Wait for Rx FIFO to have something */ + 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; + } + + /* Discard */ + read_reg(spmi, SPMI_RSP_REG); + + return 0; +} + +static int spmi_controller_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)) { + dev_err_probe(&pdev->dev, PTR_ERR(ctrl), + "Can't allocate spmi_controller data\n"); + return -ENOMEM; + } + + spmi = spmi_controller_get_drvdata(ctrl); + + spmi->regs = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(spmi->regs)) { + dev_err_probe(&pdev->dev, PTR_ERR(spmi->regs), + "Can't get ioremap regs\n"); + return PTR_ERR(spmi->regs); + } + + ctrl->dev.of_node = of_node_get(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) { + dev_err(&pdev->dev, + "spmi_controller_add failed with error %d!\n", ret); + return ret; + } + + return 0; +} + +static const struct of_device_id spmi_controller_match_table[] = { + { .compatible = "apple,spmi", }, + {} +}; +MODULE_DEVICE_TABLE(of, spmi_controller_match_table); + +static struct platform_driver spmi_controller_driver = { + .probe = spmi_controller_probe, + .driver = { + .name = "apple-spmi", + .of_match_table = spmi_controller_match_table, + }, +}; +module_platform_driver(spmi_controller_driver); + +MODULE_AUTHOR("Jean-Francois Bortolotti <jeff@borto.fr>"); +MODULE_DESCRIPTION("Apple SoC SPMI driver"); +MODULE_LICENSE("GPL");