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// 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);
}
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