1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * TWL6040 clock module driver for OMAP4 McPDM functional clock |
4 | * |
5 | * Copyright (C) 2012 Texas Instruments Inc. |
6 | * Peter Ujfalusi <peter.ujfalusi@ti.com> |
7 | */ |
8 | |
9 | #include <linux/module.h> |
10 | #include <linux/slab.h> |
11 | #include <linux/platform_device.h> |
12 | #include <linux/mfd/twl6040.h> |
13 | #include <linux/clk-provider.h> |
14 | |
15 | struct twl6040_pdmclk { |
16 | struct twl6040 *twl6040; |
17 | struct device *dev; |
18 | struct clk_hw pdmclk_hw; |
19 | int enabled; |
20 | }; |
21 | |
22 | static int twl6040_pdmclk_is_prepared(struct clk_hw *hw) |
23 | { |
24 | struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk, |
25 | pdmclk_hw); |
26 | |
27 | return pdmclk->enabled; |
28 | } |
29 | |
30 | static int twl6040_pdmclk_reset_one_clock(struct twl6040_pdmclk *pdmclk, |
31 | unsigned int reg) |
32 | { |
33 | const u8 reset_mask = TWL6040_HPLLRST; /* Same for HPPLL and LPPLL */ |
34 | int ret; |
35 | |
36 | ret = twl6040_set_bits(twl6040: pdmclk->twl6040, reg, mask: reset_mask); |
37 | if (ret < 0) |
38 | return ret; |
39 | |
40 | ret = twl6040_clear_bits(twl6040: pdmclk->twl6040, reg, mask: reset_mask); |
41 | if (ret < 0) |
42 | return ret; |
43 | |
44 | return 0; |
45 | } |
46 | |
47 | /* |
48 | * TWL6040A2 Phoenix Audio IC erratum #6: "PDM Clock Generation Issue At |
49 | * Cold Temperature". This affects cold boot and deeper idle states it |
50 | * seems. The workaround consists of resetting HPPLL and LPPLL. |
51 | */ |
52 | static int twl6040_pdmclk_quirk_reset_clocks(struct twl6040_pdmclk *pdmclk) |
53 | { |
54 | int ret; |
55 | |
56 | ret = twl6040_pdmclk_reset_one_clock(pdmclk, TWL6040_REG_HPPLLCTL); |
57 | if (ret) |
58 | return ret; |
59 | |
60 | ret = twl6040_pdmclk_reset_one_clock(pdmclk, TWL6040_REG_LPPLLCTL); |
61 | if (ret) |
62 | return ret; |
63 | |
64 | return 0; |
65 | } |
66 | |
67 | static int twl6040_pdmclk_prepare(struct clk_hw *hw) |
68 | { |
69 | struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk, |
70 | pdmclk_hw); |
71 | int ret; |
72 | |
73 | ret = twl6040_power(twl6040: pdmclk->twl6040, on: 1); |
74 | if (ret) |
75 | return ret; |
76 | |
77 | ret = twl6040_pdmclk_quirk_reset_clocks(pdmclk); |
78 | if (ret) |
79 | goto out_err; |
80 | |
81 | pdmclk->enabled = 1; |
82 | |
83 | return 0; |
84 | |
85 | out_err: |
86 | dev_err(pdmclk->dev, "%s: error %i\n" , __func__, ret); |
87 | twl6040_power(twl6040: pdmclk->twl6040, on: 0); |
88 | |
89 | return ret; |
90 | } |
91 | |
92 | static void twl6040_pdmclk_unprepare(struct clk_hw *hw) |
93 | { |
94 | struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk, |
95 | pdmclk_hw); |
96 | int ret; |
97 | |
98 | ret = twl6040_power(twl6040: pdmclk->twl6040, on: 0); |
99 | if (!ret) |
100 | pdmclk->enabled = 0; |
101 | |
102 | } |
103 | |
104 | static unsigned long twl6040_pdmclk_recalc_rate(struct clk_hw *hw, |
105 | unsigned long parent_rate) |
106 | { |
107 | struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk, |
108 | pdmclk_hw); |
109 | |
110 | return twl6040_get_sysclk(twl6040: pdmclk->twl6040); |
111 | } |
112 | |
113 | static const struct clk_ops twl6040_pdmclk_ops = { |
114 | .is_prepared = twl6040_pdmclk_is_prepared, |
115 | .prepare = twl6040_pdmclk_prepare, |
116 | .unprepare = twl6040_pdmclk_unprepare, |
117 | .recalc_rate = twl6040_pdmclk_recalc_rate, |
118 | }; |
119 | |
120 | static const struct clk_init_data twl6040_pdmclk_init = { |
121 | .name = "pdmclk" , |
122 | .ops = &twl6040_pdmclk_ops, |
123 | .flags = CLK_GET_RATE_NOCACHE, |
124 | }; |
125 | |
126 | static int twl6040_pdmclk_probe(struct platform_device *pdev) |
127 | { |
128 | struct twl6040 *twl6040 = dev_get_drvdata(dev: pdev->dev.parent); |
129 | struct twl6040_pdmclk *clkdata; |
130 | int ret; |
131 | |
132 | clkdata = devm_kzalloc(dev: &pdev->dev, size: sizeof(*clkdata), GFP_KERNEL); |
133 | if (!clkdata) |
134 | return -ENOMEM; |
135 | |
136 | clkdata->dev = &pdev->dev; |
137 | clkdata->twl6040 = twl6040; |
138 | |
139 | clkdata->pdmclk_hw.init = &twl6040_pdmclk_init; |
140 | ret = devm_clk_hw_register(dev: &pdev->dev, hw: &clkdata->pdmclk_hw); |
141 | if (ret) |
142 | return ret; |
143 | |
144 | platform_set_drvdata(pdev, data: clkdata); |
145 | |
146 | return devm_of_clk_add_hw_provider(dev: &pdev->dev, get: of_clk_hw_simple_get, |
147 | data: &clkdata->pdmclk_hw); |
148 | } |
149 | |
150 | static struct platform_driver twl6040_pdmclk_driver = { |
151 | .driver = { |
152 | .name = "twl6040-pdmclk" , |
153 | }, |
154 | .probe = twl6040_pdmclk_probe, |
155 | }; |
156 | |
157 | module_platform_driver(twl6040_pdmclk_driver); |
158 | |
159 | MODULE_DESCRIPTION("TWL6040 clock driver for McPDM functional clock" ); |
160 | MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>" ); |
161 | MODULE_ALIAS("platform:twl6040-pdmclk" ); |
162 | MODULE_LICENSE("GPL" ); |
163 | |