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path: root/drivers/clk/baikal-t1/clk-ccu-pll.c
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Diffstat (limited to 'drivers/clk/baikal-t1/clk-ccu-pll.c')
-rw-r--r--drivers/clk/baikal-t1/clk-ccu-pll.c277
1 files changed, 277 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..fce02ce77
--- /dev/null
+++ b/drivers/clk/baikal-t1/clk-ccu-pll.c
@@ -0,0 +1,277 @@
+// 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/platform_device.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, _features) \
+ { \
+ .id = _id, \
+ .name = _name, \
+ .parent_name = _pname, \
+ .base = _base, \
+ .flags = _flags, \
+ .features = _features, \
+ }
+
+#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;
+ unsigned long features;
+};
+
+/*
+ * 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_BASIC),
+ CCU_PLL_INFO(CCU_SATA_PLL, "sata_pll", "ref_clk", CCU_SATA_PLL_BASE,
+ CLK_IS_CRITICAL | CLK_SET_RATE_GATE, 0),
+ CCU_PLL_INFO(CCU_DDR_PLL, "ddr_pll", "ref_clk", CCU_DDR_PLL_BASE,
+ CLK_IS_CRITICAL | CLK_SET_RATE_GATE, 0),
+ CCU_PLL_INFO(CCU_PCIE_PLL, "pcie_pll", "ref_clk", CCU_PCIE_PLL_BASE,
+ CLK_IS_CRITICAL, CCU_PLL_BASIC),
+ CCU_PLL_INFO(CCU_ETH_PLL, "eth_pll", "ref_clk", CCU_ETH_PLL_BASE,
+ CLK_IS_CRITICAL | CLK_SET_RATE_GATE, 0)
+};
+
+struct ccu_pll_data {
+ struct device_node *np;
+ struct regmap *sys_regs;
+ struct ccu_pll *plls[CCU_PLL_NUM];
+};
+
+static struct ccu_pll_data *pll_data;
+
+static struct ccu_pll *ccu_pll_find_desc(struct ccu_pll_data *data,
+ unsigned int clk_id)
+{
+ int idx;
+
+ for (idx = 0; idx < CCU_PLL_NUM; ++idx) {
+ if (pll_info[idx].id == clk_id)
+ return data->plls[idx];
+ }
+
+ 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)) {
+ if (pll != ERR_PTR(-EPROBE_DEFER))
+ 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, bool defer)
+{
+ 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};
+
+ /* Defer non-basic PLLs allocation for the probe stage */
+ if (!!(info->features & CCU_PLL_BASIC) ^ defer) {
+ if (!data->plls[idx])
+ data->plls[idx] = ERR_PTR(-EPROBE_DEFER);
+
+ continue;
+ }
+
+ 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;
+ init.features = info->features;
+
+ 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;
+ }
+ }
+
+ return 0;
+
+err_hw_unregister:
+ for (--idx; idx >= 0; --idx) {
+ if (!!(pll_info[idx].features & CCU_PLL_BASIC) ^ defer)
+ continue;
+
+ ccu_pll_hw_unregister(data->plls[idx]);
+ }
+
+ return ret;
+}
+
+static void ccu_pll_clk_unregister(struct ccu_pll_data *data, bool defer)
+{
+ int idx;
+
+ /* Uninstall only the clocks registered on the specfied stage */
+ for (idx = 0; idx < CCU_PLL_NUM; ++idx) {
+ if (!!(pll_info[idx].features & CCU_PLL_BASIC) ^ defer)
+ continue;
+
+ ccu_pll_hw_unregister(data->plls[idx]);
+ }
+}
+
+static int ccu_pll_of_register(struct ccu_pll_data *data)
+{
+ int ret;
+
+ 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));
+ }
+
+ return ret;
+}
+
+static int ccu_pll_probe(struct platform_device *pdev)
+{
+ struct ccu_pll_data *data = pll_data;
+
+ if (!data)
+ return -EINVAL;
+
+ return ccu_pll_clk_register(data, false);
+}
+
+static const struct of_device_id ccu_pll_of_match[] = {
+ { .compatible = "baikal,bt1-ccu-pll" },
+ { }
+};
+
+static struct platform_driver ccu_pll_driver = {
+ .probe = ccu_pll_probe,
+ .driver = {
+ .name = "clk-ccu-pll",
+ .of_match_table = ccu_pll_of_match,
+ .suppress_bind_attrs = true,
+ },
+};
+builtin_platform_driver(ccu_pll_driver);
+
+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, true);
+ if (ret)
+ goto err_free_data;
+
+ ret = ccu_pll_of_register(data);
+ if (ret)
+ goto err_clk_unregister;
+
+ pll_data = data;
+
+ return;
+
+err_clk_unregister:
+ ccu_pll_clk_unregister(data, true);
+
+err_free_data:
+ ccu_pll_free_data(data);
+}
+CLK_OF_DECLARE_DRIVER(ccu_pll, "baikal,bt1-ccu-pll", ccu_pll_init);