1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Hisilicon clock driver 4 * 5 * Copyright (c) 2013-2017 Hisilicon Limited. 6 * Copyright (c) 2017 Linaro Limited. 7 * 8 * Author: Kai Zhao <zhaokai1@hisilicon.com> 9 * Tao Wang <kevin.wangtao@hisilicon.com> 10 * Leo Yan <leo.yan@linaro.org> 11 */ 12 13 #include <linux/clk-provider.h> 14 #include <linux/device.h> 15 #include <linux/err.h> 16 #include <linux/init.h> 17 #include <linux/io.h> 18 #include <linux/mailbox_client.h> 19 #include <linux/module.h> 20 #include <linux/of.h> 21 #include <linux/platform_device.h> 22 #include <dt-bindings/clock/hi3660-clock.h> 23 24 #define HI3660_STUB_CLOCK_DATA (0x70) 25 #define MHZ (1000 * 1000) 26 27 #define DEFINE_CLK_STUB(_id, _cmd, _name) \ 28 { \ 29 .id = (_id), \ 30 .cmd = (_cmd), \ 31 .hw.init = &(struct clk_init_data) { \ 32 .name = #_name, \ 33 .ops = &hi3660_stub_clk_ops, \ 34 .num_parents = 0, \ 35 .flags = CLK_GET_RATE_NOCACHE, \ 36 }, \ 37 }, 38 39 #define to_stub_clk(_hw) container_of(_hw, struct hi3660_stub_clk, hw) 40 41 struct hi3660_stub_clk_chan { 42 struct mbox_client cl; 43 struct mbox_chan *mbox; 44 }; 45 46 struct hi3660_stub_clk { 47 unsigned int id; 48 struct clk_hw hw; 49 unsigned int cmd; 50 unsigned int msg[8]; 51 unsigned int rate; 52 }; 53 54 static void __iomem *freq_reg; 55 static struct hi3660_stub_clk_chan stub_clk_chan; 56 57 static unsigned long hi3660_stub_clk_recalc_rate(struct clk_hw *hw, 58 unsigned long parent_rate) 59 { 60 struct hi3660_stub_clk *stub_clk = to_stub_clk(hw); 61 62 /* 63 * LPM3 writes back the CPU frequency in shared SRAM so read 64 * back the frequency. 65 */ 66 stub_clk->rate = readl(freq_reg + (stub_clk->id << 2)) * MHZ; 67 return stub_clk->rate; 68 } 69 70 static long hi3660_stub_clk_round_rate(struct clk_hw *hw, unsigned long rate, 71 unsigned long *prate) 72 { 73 /* 74 * LPM3 handles rate rounding so just return whatever 75 * rate is requested. 76 */ 77 return rate; 78 } 79 80 static int hi3660_stub_clk_set_rate(struct clk_hw *hw, unsigned long rate, 81 unsigned long parent_rate) 82 { 83 struct hi3660_stub_clk *stub_clk = to_stub_clk(hw); 84 85 stub_clk->msg[0] = stub_clk->cmd; 86 stub_clk->msg[1] = rate / MHZ; 87 88 dev_dbg(stub_clk_chan.cl.dev, "set rate msg[0]=0x%x msg[1]=0x%x\n", 89 stub_clk->msg[0], stub_clk->msg[1]); 90 91 mbox_send_message(stub_clk_chan.mbox, stub_clk->msg); 92 mbox_client_txdone(stub_clk_chan.mbox, 0); 93 94 stub_clk->rate = rate; 95 return 0; 96 } 97 98 static const struct clk_ops hi3660_stub_clk_ops = { 99 .recalc_rate = hi3660_stub_clk_recalc_rate, 100 .round_rate = hi3660_stub_clk_round_rate, 101 .set_rate = hi3660_stub_clk_set_rate, 102 }; 103 104 static struct hi3660_stub_clk hi3660_stub_clks[HI3660_CLK_STUB_NUM] = { 105 DEFINE_CLK_STUB(HI3660_CLK_STUB_CLUSTER0, 0x0001030A, "cpu-cluster.0") 106 DEFINE_CLK_STUB(HI3660_CLK_STUB_CLUSTER1, 0x0002030A, "cpu-cluster.1") 107 DEFINE_CLK_STUB(HI3660_CLK_STUB_GPU, 0x0003030A, "clk-g3d") 108 DEFINE_CLK_STUB(HI3660_CLK_STUB_DDR, 0x00040309, "clk-ddrc") 109 }; 110 111 static struct clk_hw *hi3660_stub_clk_hw_get(struct of_phandle_args *clkspec, 112 void *data) 113 { 114 unsigned int idx = clkspec->args[0]; 115 116 if (idx >= HI3660_CLK_STUB_NUM) { 117 pr_err("%s: invalid index %u\n", __func__, idx); 118 return ERR_PTR(-EINVAL); 119 } 120 121 return &hi3660_stub_clks[idx].hw; 122 } 123 124 static int hi3660_stub_clk_probe(struct platform_device *pdev) 125 { 126 struct device *dev = &pdev->dev; 127 struct resource *res; 128 unsigned int i; 129 int ret; 130 131 /* Use mailbox client without blocking */ 132 stub_clk_chan.cl.dev = dev; 133 stub_clk_chan.cl.tx_done = NULL; 134 stub_clk_chan.cl.tx_block = false; 135 stub_clk_chan.cl.knows_txdone = false; 136 137 /* Allocate mailbox channel */ 138 stub_clk_chan.mbox = mbox_request_channel(&stub_clk_chan.cl, 0); 139 if (IS_ERR(stub_clk_chan.mbox)) 140 return PTR_ERR(stub_clk_chan.mbox); 141 142 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 143 if (!res) 144 return -EINVAL; 145 freq_reg = devm_ioremap(dev, res->start, resource_size(res)); 146 if (!freq_reg) 147 return -ENOMEM; 148 149 freq_reg += HI3660_STUB_CLOCK_DATA; 150 151 for (i = 0; i < HI3660_CLK_STUB_NUM; i++) { 152 ret = devm_clk_hw_register(&pdev->dev, &hi3660_stub_clks[i].hw); 153 if (ret) 154 return ret; 155 } 156 157 return devm_of_clk_add_hw_provider(&pdev->dev, hi3660_stub_clk_hw_get, 158 hi3660_stub_clks); 159 } 160 161 static const struct of_device_id hi3660_stub_clk_of_match[] = { 162 { .compatible = "hisilicon,hi3660-stub-clk", }, 163 {} 164 }; 165 166 static struct platform_driver hi3660_stub_clk_driver = { 167 .probe = hi3660_stub_clk_probe, 168 .driver = { 169 .name = "hi3660-stub-clk", 170 .of_match_table = hi3660_stub_clk_of_match, 171 }, 172 }; 173 174 static int __init hi3660_stub_clk_init(void) 175 { 176 return platform_driver_register(&hi3660_stub_clk_driver); 177 } 178 subsys_initcall(hi3660_stub_clk_init); 179