From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- drivers/soc/litex/Kconfig | 20 ++++++ drivers/soc/litex/Makefile | 3 + drivers/soc/litex/litex_soc_ctrl.c | 143 +++++++++++++++++++++++++++++++++++++ 3 files changed, 166 insertions(+) create mode 100644 drivers/soc/litex/Kconfig create mode 100644 drivers/soc/litex/Makefile create mode 100644 drivers/soc/litex/litex_soc_ctrl.c (limited to 'drivers/soc/litex') diff --git a/drivers/soc/litex/Kconfig b/drivers/soc/litex/Kconfig new file mode 100644 index 0000000000..e6ba3573a7 --- /dev/null +++ b/drivers/soc/litex/Kconfig @@ -0,0 +1,20 @@ +# SPDX-License_Identifier: GPL-2.0 + +menu "Enable LiteX SoC Builder specific drivers" + +config LITEX + bool + +config LITEX_SOC_CONTROLLER + tristate "Enable LiteX SoC Controller driver" + depends on OF || COMPILE_TEST + depends on HAS_IOMEM + select LITEX + help + This option enables the SoC Controller Driver which verifies + LiteX CSR access and provides common litex_[read|write]* + accessors. + All drivers that use functions from litex.h must depend on + LITEX. + +endmenu diff --git a/drivers/soc/litex/Makefile b/drivers/soc/litex/Makefile new file mode 100644 index 0000000000..98ff7325b1 --- /dev/null +++ b/drivers/soc/litex/Makefile @@ -0,0 +1,3 @@ +# SPDX-License_Identifier: GPL-2.0 + +obj-$(CONFIG_LITEX_SOC_CONTROLLER) += litex_soc_ctrl.o diff --git a/drivers/soc/litex/litex_soc_ctrl.c b/drivers/soc/litex/litex_soc_ctrl.c new file mode 100644 index 0000000000..f75790091d --- /dev/null +++ b/drivers/soc/litex/litex_soc_ctrl.c @@ -0,0 +1,143 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * LiteX SoC Controller Driver + * + * Copyright (C) 2020 Antmicro + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* reset register located at the base address */ +#define RESET_REG_OFF 0x00 +#define RESET_REG_VALUE 0x00000001 + +#define SCRATCH_REG_OFF 0x04 +#define SCRATCH_REG_VALUE 0x12345678 +#define SCRATCH_TEST_VALUE 0xdeadbeef + +/* + * Check LiteX CSR read/write access + * + * This function reads and writes a scratch register in order to verify if CSR + * access works. + * + * In case any problems are detected, the driver should panic. + * + * Access to the LiteX CSR is, by design, done in CPU native endianness. + * The driver should not dynamically configure access functions when + * the endianness mismatch is detected. Such situation indicates problems in + * the soft SoC design and should be solved at the LiteX generator level, + * not in the software. + */ +static int litex_check_csr_access(void __iomem *reg_addr) +{ + unsigned long reg; + + reg = litex_read32(reg_addr + SCRATCH_REG_OFF); + + if (reg != SCRATCH_REG_VALUE) { + panic("Scratch register read error - the system is probably broken! Expected: 0x%x but got: 0x%lx", + SCRATCH_REG_VALUE, reg); + return -EINVAL; + } + + litex_write32(reg_addr + SCRATCH_REG_OFF, SCRATCH_TEST_VALUE); + reg = litex_read32(reg_addr + SCRATCH_REG_OFF); + + if (reg != SCRATCH_TEST_VALUE) { + panic("Scratch register write error - the system is probably broken! Expected: 0x%x but got: 0x%lx", + SCRATCH_TEST_VALUE, reg); + return -EINVAL; + } + + /* restore original value of the SCRATCH register */ + litex_write32(reg_addr + SCRATCH_REG_OFF, SCRATCH_REG_VALUE); + + pr_info("LiteX SoC Controller driver initialized"); + + return 0; +} + +struct litex_soc_ctrl_device { + void __iomem *base; + struct notifier_block reset_nb; +}; + +static int litex_reset_handler(struct notifier_block *this, unsigned long mode, + void *cmd) +{ + struct litex_soc_ctrl_device *soc_ctrl_dev = + container_of(this, struct litex_soc_ctrl_device, reset_nb); + + litex_write32(soc_ctrl_dev->base + RESET_REG_OFF, RESET_REG_VALUE); + return NOTIFY_DONE; +} + +#ifdef CONFIG_OF +static const struct of_device_id litex_soc_ctrl_of_match[] = { + {.compatible = "litex,soc-controller"}, + {}, +}; +MODULE_DEVICE_TABLE(of, litex_soc_ctrl_of_match); +#endif /* CONFIG_OF */ + +static int litex_soc_ctrl_probe(struct platform_device *pdev) +{ + struct litex_soc_ctrl_device *soc_ctrl_dev; + int error; + + soc_ctrl_dev = devm_kzalloc(&pdev->dev, sizeof(*soc_ctrl_dev), GFP_KERNEL); + if (!soc_ctrl_dev) + return -ENOMEM; + + soc_ctrl_dev->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(soc_ctrl_dev->base)) + return PTR_ERR(soc_ctrl_dev->base); + + error = litex_check_csr_access(soc_ctrl_dev->base); + if (error) + return error; + + platform_set_drvdata(pdev, soc_ctrl_dev); + + soc_ctrl_dev->reset_nb.notifier_call = litex_reset_handler; + soc_ctrl_dev->reset_nb.priority = 128; + error = register_restart_handler(&soc_ctrl_dev->reset_nb); + if (error) { + dev_warn(&pdev->dev, "cannot register restart handler: %d\n", + error); + } + + return 0; +} + +static int litex_soc_ctrl_remove(struct platform_device *pdev) +{ + struct litex_soc_ctrl_device *soc_ctrl_dev = platform_get_drvdata(pdev); + + unregister_restart_handler(&soc_ctrl_dev->reset_nb); + return 0; +} + +static struct platform_driver litex_soc_ctrl_driver = { + .driver = { + .name = "litex-soc-controller", + .of_match_table = of_match_ptr(litex_soc_ctrl_of_match) + }, + .probe = litex_soc_ctrl_probe, + .remove = litex_soc_ctrl_remove, +}; + +module_platform_driver(litex_soc_ctrl_driver); +MODULE_DESCRIPTION("LiteX SoC Controller driver"); +MODULE_AUTHOR("Antmicro "); +MODULE_LICENSE("GPL v2"); -- cgit v1.2.3