diff options
Diffstat (limited to 'drivers/clk/baikal-t1/clk-ccu-pll.c')
| -rw-r--r-- | drivers/clk/baikal-t1/clk-ccu-pll.c | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/drivers/clk/baikal-t1/clk-ccu-pll.c b/drivers/clk/baikal-t1/clk-ccu-pll.c new file mode 100644 index 000000000..2445d4b12 --- /dev/null +++ b/drivers/clk/baikal-t1/clk-ccu-pll.c @@ -0,0 +1,206 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2020 BAIKAL ELECTRONICS, JSC + * + * Authors: + * Serge Semin <Sergey.Semin@baikalelectronics.ru> + * Dmitry Dunaev <dmitry.dunaev@baikalelectronics.ru> + * + * Baikal-T1 CCU PLL clocks driver + */ + +#define pr_fmt(fmt) "bt1-ccu-pll: " fmt + +#include <linux/kernel.h> +#include <linux/printk.h> +#include <linux/slab.h> +#include <linux/clk-provider.h> +#include <linux/mfd/syscon.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/ioport.h> +#include <linux/regmap.h> + +#include <dt-bindings/clock/bt1-ccu.h> + +#include "ccu-pll.h" + +#define CCU_CPU_PLL_BASE 0x000 +#define CCU_SATA_PLL_BASE 0x008 +#define CCU_DDR_PLL_BASE 0x010 +#define CCU_PCIE_PLL_BASE 0x018 +#define CCU_ETH_PLL_BASE 0x020 + +#define CCU_PLL_INFO(_id, _name, _pname, _base, _flags) \ + { \ + .id = _id, \ + .name = _name, \ + .parent_name = _pname, \ + .base = _base, \ + .flags = _flags \ + } + +#define CCU_PLL_NUM ARRAY_SIZE(pll_info) + +struct ccu_pll_info { + unsigned int id; + const char *name; + const char *parent_name; + unsigned int base; + unsigned long flags; +}; + +/* + * Alas we have to mark all PLLs as critical. CPU and DDR PLLs are sources of + * CPU cores and DDR controller reference clocks, due to which they obviously + * shouldn't be ever gated. SATA and PCIe PLLs are the parents of APB-bus and + * DDR controller AXI-bus clocks. If they are gated the system will be + * unusable. Moreover disabling SATA and Ethernet PLLs causes automatic reset + * of the corresponding subsystems. So until we aren't ready to re-initialize + * all the devices consuming those PLLs, they will be marked as critical too. + */ +static const struct ccu_pll_info pll_info[] = { + CCU_PLL_INFO(CCU_CPU_PLL, "cpu_pll", "ref_clk", CCU_CPU_PLL_BASE, + CLK_IS_CRITICAL), + CCU_PLL_INFO(CCU_SATA_PLL, "sata_pll", "ref_clk", CCU_SATA_PLL_BASE, + CLK_IS_CRITICAL | CLK_SET_RATE_GATE), + CCU_PLL_INFO(CCU_DDR_PLL, "ddr_pll", "ref_clk", CCU_DDR_PLL_BASE, + CLK_IS_CRITICAL | CLK_SET_RATE_GATE), + CCU_PLL_INFO(CCU_PCIE_PLL, "pcie_pll", "ref_clk", CCU_PCIE_PLL_BASE, + CLK_IS_CRITICAL), + CCU_PLL_INFO(CCU_ETH_PLL, "eth_pll", "ref_clk", CCU_ETH_PLL_BASE, + CLK_IS_CRITICAL | CLK_SET_RATE_GATE) +}; + +struct ccu_pll_data { + struct device_node *np; + struct regmap *sys_regs; + struct ccu_pll *plls[CCU_PLL_NUM]; +}; + +static struct ccu_pll *ccu_pll_find_desc(struct ccu_pll_data *data, + unsigned int clk_id) +{ + struct ccu_pll *pll; + int idx; + + for (idx = 0; idx < CCU_PLL_NUM; ++idx) { + pll = data->plls[idx]; + if (pll && pll->id == clk_id) + return pll; + } + + return ERR_PTR(-EINVAL); +} + +static struct ccu_pll_data *ccu_pll_create_data(struct device_node *np) +{ + struct ccu_pll_data *data; + + data = kzalloc(sizeof(*data), GFP_KERNEL); + if (!data) + return ERR_PTR(-ENOMEM); + + data->np = np; + + return data; +} + +static void ccu_pll_free_data(struct ccu_pll_data *data) +{ + kfree(data); +} + +static int ccu_pll_find_sys_regs(struct ccu_pll_data *data) +{ + data->sys_regs = syscon_node_to_regmap(data->np->parent); + if (IS_ERR(data->sys_regs)) { + pr_err("Failed to find syscon regs for '%s'\n", + of_node_full_name(data->np)); + return PTR_ERR(data->sys_regs); + } + + return 0; +} + +static struct clk_hw *ccu_pll_of_clk_hw_get(struct of_phandle_args *clkspec, + void *priv) +{ + struct ccu_pll_data *data = priv; + struct ccu_pll *pll; + unsigned int clk_id; + + clk_id = clkspec->args[0]; + pll = ccu_pll_find_desc(data, clk_id); + if (IS_ERR(pll)) { + pr_info("Invalid PLL clock ID %d specified\n", clk_id); + return ERR_CAST(pll); + } + + return ccu_pll_get_clk_hw(pll); +} + +static int ccu_pll_clk_register(struct ccu_pll_data *data) +{ + int idx, ret; + + for (idx = 0; idx < CCU_PLL_NUM; ++idx) { + const struct ccu_pll_info *info = &pll_info[idx]; + struct ccu_pll_init_data init = {0}; + + init.id = info->id; + init.name = info->name; + init.parent_name = info->parent_name; + init.base = info->base; + init.sys_regs = data->sys_regs; + init.np = data->np; + init.flags = info->flags; + + data->plls[idx] = ccu_pll_hw_register(&init); + if (IS_ERR(data->plls[idx])) { + ret = PTR_ERR(data->plls[idx]); + pr_err("Couldn't register PLL hw '%s'\n", + init.name); + goto err_hw_unregister; + } + } + + ret = of_clk_add_hw_provider(data->np, ccu_pll_of_clk_hw_get, data); + if (ret) { + pr_err("Couldn't register PLL provider of '%s'\n", + of_node_full_name(data->np)); + goto err_hw_unregister; + } + + return 0; + +err_hw_unregister: + for (--idx; idx >= 0; --idx) + ccu_pll_hw_unregister(data->plls[idx]); + + return ret; +} + +static __init void ccu_pll_init(struct device_node *np) +{ + struct ccu_pll_data *data; + int ret; + + data = ccu_pll_create_data(np); + if (IS_ERR(data)) + return; + + ret = ccu_pll_find_sys_regs(data); + if (ret) + goto err_free_data; + + ret = ccu_pll_clk_register(data); + if (ret) + goto err_free_data; + + return; + +err_free_data: + ccu_pll_free_data(data); +} +CLK_OF_DECLARE(ccu_pll, "baikal,bt1-ccu-pll", ccu_pll_init); |