1 // SPDX-License-Identifier: BSD-3-Clause
2 /*
3  * Clock drivers for Qualcomm APQ8016, APQ8096
4  *
5  * (C) Copyright 2015 Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
6  *
7  * Based on Little Kernel driver, simplified
8  */
9 
10 #include <common.h>
11 #include <clk-uclass.h>
12 #include <dm.h>
13 #include <errno.h>
14 #include <asm/io.h>
15 #include <linux/bitops.h>
16 #include "clock-snapdragon.h"
17 
18 /* CBCR register fields */
19 #define CBCR_BRANCH_ENABLE_BIT  BIT(0)
20 #define CBCR_BRANCH_OFF_BIT     BIT(31)
21 
22 extern ulong msm_set_rate(struct clk *clk, ulong rate);
23 
24 /* Enable clock controlled by CBC soft macro */
25 void clk_enable_cbc(phys_addr_t cbcr)
26 {
27 	setbits_le32(cbcr, CBCR_BRANCH_ENABLE_BIT);
28 
29 	while (readl(cbcr) & CBCR_BRANCH_OFF_BIT)
30 		;
31 }
32 
33 void clk_enable_gpll0(phys_addr_t base, const struct pll_vote_clk *gpll0)
34 {
35 	if (readl(base + gpll0->status) & gpll0->status_bit)
36 		return; /* clock already enabled */
37 
38 	setbits_le32(base + gpll0->ena_vote, gpll0->vote_bit);
39 
40 	while ((readl(base + gpll0->status) & gpll0->status_bit) == 0)
41 		;
42 }
43 
44 #define BRANCH_ON_VAL (0)
45 #define BRANCH_NOC_FSM_ON_VAL BIT(29)
46 #define BRANCH_CHECK_MASK GENMASK(31, 28)
47 
48 void clk_enable_vote_clk(phys_addr_t base, const struct vote_clk *vclk)
49 {
50 	u32 val;
51 
52 	setbits_le32(base + vclk->ena_vote, vclk->vote_bit);
53 	do {
54 		val = readl(base + vclk->cbcr_reg);
55 		val &= BRANCH_CHECK_MASK;
56 	} while ((val != BRANCH_ON_VAL) && (val != BRANCH_NOC_FSM_ON_VAL));
57 }
58 
59 #define APPS_CMD_RGCR_UPDATE BIT(0)
60 
61 /* Update clock command via CMD_RGCR */
62 void clk_bcr_update(phys_addr_t apps_cmd_rgcr)
63 {
64 	setbits_le32(apps_cmd_rgcr, APPS_CMD_RGCR_UPDATE);
65 
66 	/* Wait for frequency to be updated. */
67 	while (readl(apps_cmd_rgcr) & APPS_CMD_RGCR_UPDATE)
68 		;
69 }
70 
71 #define CFG_MODE_DUAL_EDGE (0x2 << 12) /* Counter mode */
72 
73 #define CFG_MASK 0x3FFF
74 
75 #define CFG_DIVIDER_MASK 0x1F
76 
77 /* root set rate for clocks with half integer and MND divider */
78 void clk_rcg_set_rate_mnd(phys_addr_t base, const struct bcr_regs *regs,
79 			  int div, int m, int n, int source)
80 {
81 	u32 cfg;
82 	/* M value for MND divider. */
83 	u32 m_val = m;
84 	/* NOT(N-M) value for MND divider. */
85 	u32 n_val = ~((n) - (m)) * !!(n);
86 	/* NOT 2D value for MND divider. */
87 	u32 d_val = ~(n);
88 
89 	/* Program MND values */
90 	writel(m_val, base + regs->M);
91 	writel(n_val, base + regs->N);
92 	writel(d_val, base + regs->D);
93 
94 	/* setup src select and divider */
95 	cfg  = readl(base + regs->cfg_rcgr);
96 	cfg &= ~CFG_MASK;
97 	cfg |= source & CFG_CLK_SRC_MASK; /* Select clock source */
98 
99 	/* Set the divider; HW permits fraction dividers (+0.5), but
100 	   for simplicity, we will support integers only */
101 	if (div)
102 		cfg |= (2 * div - 1) & CFG_DIVIDER_MASK;
103 
104 	if (n_val)
105 		cfg |= CFG_MODE_DUAL_EDGE;
106 
107 	writel(cfg, base + regs->cfg_rcgr); /* Write new clock configuration */
108 
109 	/* Inform h/w to start using the new config. */
110 	clk_bcr_update(base + regs->cmd_rcgr);
111 }
112 
113 static int msm_clk_probe(struct udevice *dev)
114 {
115 	struct msm_clk_priv *priv = dev_get_priv(dev);
116 
117 	priv->base = devfdt_get_addr(dev);
118 	if (priv->base == FDT_ADDR_T_NONE)
119 		return -EINVAL;
120 
121 	return 0;
122 }
123 
124 static ulong msm_clk_set_rate(struct clk *clk, ulong rate)
125 {
126 	return msm_set_rate(clk, rate);
127 }
128 
129 static struct clk_ops msm_clk_ops = {
130 	.set_rate = msm_clk_set_rate,
131 };
132 
133 static const struct udevice_id msm_clk_ids[] = {
134 	{ .compatible = "qcom,gcc-msm8916" },
135 	{ .compatible = "qcom,gcc-apq8016" },
136 	{ .compatible = "qcom,gcc-msm8996" },
137 	{ .compatible = "qcom,gcc-apq8096" },
138 	{ }
139 };
140 
141 U_BOOT_DRIVER(clk_msm) = {
142 	.name		= "clk_msm",
143 	.id		= UCLASS_CLK,
144 	.of_match	= msm_clk_ids,
145 	.ops		= &msm_clk_ops,
146 	.priv_auto_alloc_size = sizeof(struct msm_clk_priv),
147 	.probe		= msm_clk_probe,
148 };
149