diff options
Diffstat (limited to 'drivers/clk/baikal-t1/ccu-rst.c')
| -rw-r--r-- | drivers/clk/baikal-t1/ccu-rst.c | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/drivers/clk/baikal-t1/ccu-rst.c b/drivers/clk/baikal-t1/ccu-rst.c new file mode 100644 index 000000000000..7db52633270f --- /dev/null +++ b/drivers/clk/baikal-t1/ccu-rst.c @@ -0,0 +1,151 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2021 BAIKAL ELECTRONICS, JSC + * + * Authors: + * Serge Semin <Sergey.Semin@baikalelectronics.ru> + * + * Baikal-T1 CCU Resets interface driver + */ + +#define pr_fmt(fmt) "bt1-ccu-rst: " fmt + +#include <linux/bits.h> +#include <linux/delay.h> +#include <linux/kernel.h> +#include <linux/of.h> +#include <linux/printk.h> +#include <linux/regmap.h> +#include <linux/reset-controller.h> +#include <linux/slab.h> + +#include <dt-bindings/reset/bt1-ccu.h> + +#include "ccu-rst.h" + +#define CCU_AXI_MAIN_BASE 0x030 +#define CCU_AXI_DDR_BASE 0x034 +#define CCU_AXI_SATA_BASE 0x038 +#define CCU_AXI_GMAC0_BASE 0x03C +#define CCU_AXI_GMAC1_BASE 0x040 +#define CCU_AXI_XGMAC_BASE 0x044 +#define CCU_AXI_PCIE_M_BASE 0x048 +#define CCU_AXI_PCIE_S_BASE 0x04C +#define CCU_AXI_USB_BASE 0x050 +#define CCU_AXI_HWA_BASE 0x054 +#define CCU_AXI_SRAM_BASE 0x058 + +#define CCU_SYS_SATA_REF_BASE 0x060 +#define CCU_SYS_APB_BASE 0x064 + +#define CCU_RST_DELAY_US 1 + +#define CCU_RST_TRIG(_base, _ofs) \ + { \ + .base = _base, \ + .mask = BIT(_ofs), \ + } + +struct ccu_rst_info { + unsigned int base; + unsigned int mask; +}; + +/* + * Each AXI-bus clock divider is equipped with the corresponding clock-consumer + * domain reset (it's self-deasserted reset control). + */ +static const struct ccu_rst_info axi_rst_info[] = { + [CCU_AXI_MAIN_RST] = CCU_RST_TRIG(CCU_AXI_MAIN_BASE, 1), + [CCU_AXI_DDR_RST] = CCU_RST_TRIG(CCU_AXI_DDR_BASE, 1), + [CCU_AXI_SATA_RST] = CCU_RST_TRIG(CCU_AXI_SATA_BASE, 1), + [CCU_AXI_GMAC0_RST] = CCU_RST_TRIG(CCU_AXI_GMAC0_BASE, 1), + [CCU_AXI_GMAC1_RST] = CCU_RST_TRIG(CCU_AXI_GMAC1_BASE, 1), + [CCU_AXI_XGMAC_RST] = CCU_RST_TRIG(CCU_AXI_XGMAC_BASE, 1), + [CCU_AXI_PCIE_M_RST] = CCU_RST_TRIG(CCU_AXI_PCIE_M_BASE, 1), + [CCU_AXI_PCIE_S_RST] = CCU_RST_TRIG(CCU_AXI_PCIE_S_BASE, 1), + [CCU_AXI_USB_RST] = CCU_RST_TRIG(CCU_AXI_USB_BASE, 1), + [CCU_AXI_HWA_RST] = CCU_RST_TRIG(CCU_AXI_HWA_BASE, 1), + [CCU_AXI_SRAM_RST] = CCU_RST_TRIG(CCU_AXI_SRAM_BASE, 1), +}; + +/* + * SATA reference clock domain and APB-bus domain are connected with the + * sefl-deasserted reset control, which can be activated via the corresponding + * clock divider register. DDR and PCIe sub-domains can be reset with directly + * controlled reset signals. Resetting the DDR controller though won't end up + * well while the Linux kernel is working. + */ +static const struct ccu_rst_info sys_rst_info[] = { + [CCU_SYS_SATA_REF_RST] = CCU_RST_TRIG(CCU_SYS_SATA_REF_BASE, 1), + [CCU_SYS_APB_RST] = CCU_RST_TRIG(CCU_SYS_APB_BASE, 1), +}; + +static int ccu_rst_reset(struct reset_controller_dev *rcdev, unsigned long idx) +{ + struct ccu_rst *rst = to_ccu_rst(rcdev); + const struct ccu_rst_info *info = &rst->rsts_info[idx]; + + regmap_update_bits(rst->sys_regs, info->base, info->mask, info->mask); + + /* The next delay must be enough to cover all the resets. */ + udelay(CCU_RST_DELAY_US); + + return 0; +} + +static const struct reset_control_ops ccu_rst_ops = { + .reset = ccu_rst_reset, +}; + +struct ccu_rst *ccu_rst_hw_register(const struct ccu_rst_init_data *rst_init) +{ + struct ccu_rst *rst; + int ret; + + if (!rst_init) + return ERR_PTR(-EINVAL); + + rst = kzalloc(sizeof(*rst), GFP_KERNEL); + if (!rst) + return ERR_PTR(-ENOMEM); + + rst->sys_regs = rst_init->sys_regs; + if (of_device_is_compatible(rst_init->np, "baikal,bt1-ccu-axi")) { + rst->rcdev.nr_resets = ARRAY_SIZE(axi_rst_info); + rst->rsts_info = axi_rst_info; + } else if (of_device_is_compatible(rst_init->np, "baikal,bt1-ccu-sys")) { + rst->rcdev.nr_resets = ARRAY_SIZE(sys_rst_info); + rst->rsts_info = sys_rst_info; + } else { + pr_err("Incompatible DT node '%s' specified\n", + of_node_full_name(rst_init->np)); + ret = -EINVAL; + goto err_kfree_rst; + } + + rst->rcdev.owner = THIS_MODULE; + rst->rcdev.ops = &ccu_rst_ops; + rst->rcdev.of_node = rst_init->np; + + ret = reset_controller_register(&rst->rcdev); + if (ret) { + pr_err("Couldn't register '%s' reset controller\n", + of_node_full_name(rst_init->np)); + goto err_kfree_rst; + } + + return rst; + +err_kfree_rst: + kfree(rst); + + return ERR_PTR(ret); +} + +void ccu_rst_hw_unregister(struct ccu_rst *rst) +{ + reset_controller_unregister(&rst->rcdev); + + kfree(rst); +} |