diff options
Diffstat (limited to 'drivers/spmi/spmi-apple-controller.c')
| -rw-r--r-- | drivers/spmi/spmi-apple-controller.c | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/drivers/spmi/spmi-apple-controller.c b/drivers/spmi/spmi-apple-controller.c new file mode 100644 index 000000000000..c14c4874654d --- /dev/null +++ b/drivers/spmi/spmi-apple-controller.c @@ -0,0 +1,223 @@ +// 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/bits.h> +#include <linux/delay.h> +#include <linux/io.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 SPMI_TX_FIFO_EMPTY BIT(8) + +/* Apple SPMI controler */ +struct apple_spmi { + void __iomem *regs; + struct spmi_controller *ctrl; +}; + +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 slave_id, + u16 slave_addr, u8 *__buf, size_t bc) +{ + struct apple_spmi *spmi; + u32 spmi_cmd = opc | slave_id << 8 | slave_addr << 16 | (bc - 1) | + (1 << 15); + u32 rsp; + volatile u32 status; + size_t len_to_read; + u8 i; + + spmi = spmi_controller_get_drvdata(ctrl); + + write_reg(spmi_cmd, spmi, SPMI_CMD_REG); + + /* Wait for Rx FIFO to have something */ + /* Quite ugly msleep, need to find a better way to do it */ + i = 0; + do { + status = read_reg(spmi, SPMI_STATUS_REG); + msleep(10); + i += 1; + } while ((status & SPMI_RX_FIFO_EMPTY) && i < 5); + + if (i >= 5) { + dev_err(&ctrl->dev, + "spmi_read_cmd:took to long to get the status"); + return -1; + } + + /* Read SPMI reply status */ + rsp = read_reg(spmi, SPMI_RSP_REG); + + len_to_read = 0; + /* Read SPMI data reply */ + while (!(status & SPMI_RX_FIFO_EMPTY) && (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 slave_id, + u16 slave_addr, const u8 *__buf, size_t bc) +{ + struct apple_spmi *spmi; + u32 spmi_cmd = opc | slave_id << 8 | slave_addr << 16 | (bc - 1) | + (1 << 15); + volatile u32 rsp; + volatile u32 status; + size_t i = 0, j; + + spmi = spmi_controller_get_drvdata(ctrl); + + 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 */ + /* Quite ugly msleep, need to find a better way to do it */ + i = 0; + do { + status = read_reg(spmi, SPMI_STATUS_REG); + msleep(10); + i += 1; + } while ((status & SPMI_RX_FIFO_EMPTY) && i < 5); + + if (i >= 5) { + dev_err(&ctrl->dev, + "spmi_write_cmd:took to long to get the status"); + return -1; + } + + rsp = read_reg(spmi, SPMI_RSP_REG); + (void)rsp; // TODO: check stuff here + + return 0; +} + +static int spmi_controller_probe(struct platform_device *pdev) +{ + struct apple_spmi *spmi; + struct spmi_controller *ctrl; + int ret; + + ctrl = spmi_controller_alloc(&pdev->dev, sizeof(struct apple_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->ctrl = ctrl; + platform_set_drvdata(pdev, 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); + + /* Callbacks */ + ctrl->read_cmd = spmi_read_cmd; + ctrl->write_cmd = spmi_write_cmd; + + ret = spmi_controller_add(ctrl); + if (ret) { + dev_err(&pdev->dev, + "spmi_controller_add failed with error %d!\n", ret); + goto err_put_controller; + } + + /* Let's look for other nodes in device tree like the rtc */ + ret = devm_of_platform_populate(&pdev->dev); + if (ret) { + dev_err(&pdev->dev, + "spmi_controller_probe: devm_of_platform_populate failed with error %d!\n", + ret); + goto err_devm_of_platform_populate; + } + + return 0; + +err_put_controller: + spmi_controller_put(ctrl); +err_devm_of_platform_populate: + return ret; +} + +static int spmi_del_controller(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_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, + .remove = spmi_del_controller, + .driver = { + .name = "apple-spmi", + .owner = THIS_MODULE, + .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"); |