xref: /openbmc/linux/sound/soc/fsl/fsl_utils.c (revision be2b81b5)
1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // Freescale ALSA SoC Machine driver utility
4 //
5 // Author: Timur Tabi <timur@freescale.com>
6 //
7 // Copyright 2010 Freescale Semiconductor, Inc.
8 
9 #include <linux/clk.h>
10 #include <linux/clk-provider.h>
11 #include <linux/module.h>
12 #include <linux/of_address.h>
13 #include <sound/soc.h>
14 
15 #include "fsl_utils.h"
16 
17 /**
18  * fsl_asoc_get_dma_channel - determine the dma channel for a SSI node
19  *
20  * @ssi_np: pointer to the SSI device tree node
21  * @name: name of the phandle pointing to the dma channel
22  * @dai: ASoC DAI link pointer to be filled with platform_name
23  * @dma_channel_id: dma channel id to be returned
24  * @dma_id: dma id to be returned
25  *
26  * This function determines the dma and channel id for given SSI node.  It
27  * also discovers the platform_name for the ASoC DAI link.
28  */
29 int fsl_asoc_get_dma_channel(struct device_node *ssi_np,
30 			     const char *name,
31 			     struct snd_soc_dai_link *dai,
32 			     unsigned int *dma_channel_id,
33 			     unsigned int *dma_id)
34 {
35 	struct resource res;
36 	struct device_node *dma_channel_np, *dma_np;
37 	const __be32 *iprop;
38 	int ret;
39 
40 	dma_channel_np = of_parse_phandle(ssi_np, name, 0);
41 	if (!dma_channel_np)
42 		return -EINVAL;
43 
44 	if (!of_device_is_compatible(dma_channel_np, "fsl,ssi-dma-channel")) {
45 		of_node_put(dma_channel_np);
46 		return -EINVAL;
47 	}
48 
49 	/* Determine the dev_name for the device_node.  This code mimics the
50 	 * behavior of of_device_make_bus_id(). We need this because ASoC uses
51 	 * the dev_name() of the device to match the platform (DMA) device with
52 	 * the CPU (SSI) device.  It's all ugly and hackish, but it works (for
53 	 * now).
54 	 *
55 	 * dai->platform name should already point to an allocated buffer.
56 	 */
57 	ret = of_address_to_resource(dma_channel_np, 0, &res);
58 	if (ret) {
59 		of_node_put(dma_channel_np);
60 		return ret;
61 	}
62 	snprintf((char *)dai->platforms->name, DAI_NAME_SIZE, "%llx.%pOFn",
63 		 (unsigned long long) res.start, dma_channel_np);
64 
65 	iprop = of_get_property(dma_channel_np, "cell-index", NULL);
66 	if (!iprop) {
67 		of_node_put(dma_channel_np);
68 		return -EINVAL;
69 	}
70 	*dma_channel_id = be32_to_cpup(iprop);
71 
72 	dma_np = of_get_parent(dma_channel_np);
73 	iprop = of_get_property(dma_np, "cell-index", NULL);
74 	if (!iprop) {
75 		of_node_put(dma_np);
76 		of_node_put(dma_channel_np);
77 		return -EINVAL;
78 	}
79 	*dma_id = be32_to_cpup(iprop);
80 
81 	of_node_put(dma_np);
82 	of_node_put(dma_channel_np);
83 
84 	return 0;
85 }
86 EXPORT_SYMBOL(fsl_asoc_get_dma_channel);
87 
88 /**
89  * fsl_asoc_get_pll_clocks - get two PLL clock source
90  *
91  * @dev: device pointer
92  * @pll8k_clk: PLL clock pointer for 8kHz
93  * @pll11k_clk: PLL clock pointer for 11kHz
94  *
95  * This function get two PLL clock source
96  */
97 void fsl_asoc_get_pll_clocks(struct device *dev, struct clk **pll8k_clk,
98 			     struct clk **pll11k_clk)
99 {
100 	*pll8k_clk = devm_clk_get(dev, "pll8k");
101 	if (IS_ERR(*pll8k_clk))
102 		*pll8k_clk = NULL;
103 
104 	*pll11k_clk = devm_clk_get(dev, "pll11k");
105 	if (IS_ERR(*pll11k_clk))
106 		*pll11k_clk = NULL;
107 }
108 EXPORT_SYMBOL(fsl_asoc_get_pll_clocks);
109 
110 /**
111  * fsl_asoc_reparent_pll_clocks - set clock parent if necessary
112  *
113  * @dev: device pointer
114  * @clk: root clock pointer
115  * @pll8k_clk: PLL clock pointer for 8kHz
116  * @pll11k_clk: PLL clock pointer for 11kHz
117  * @ratio: target requency for root clock
118  *
119  * This function set root clock parent according to the target ratio
120  */
121 void fsl_asoc_reparent_pll_clocks(struct device *dev, struct clk *clk,
122 				  struct clk *pll8k_clk,
123 				  struct clk *pll11k_clk, u64 ratio)
124 {
125 	struct clk *p, *pll = NULL, *npll = NULL;
126 	bool reparent = false;
127 	int ret;
128 
129 	if (!clk || !pll8k_clk || !pll11k_clk)
130 		return;
131 
132 	p = clk;
133 	while (p && pll8k_clk && pll11k_clk) {
134 		struct clk *pp = clk_get_parent(p);
135 
136 		if (clk_is_match(pp, pll8k_clk) ||
137 		    clk_is_match(pp, pll11k_clk)) {
138 			pll = pp;
139 			break;
140 		}
141 		p = pp;
142 	}
143 
144 	npll = (do_div(ratio, 8000) ? pll11k_clk : pll8k_clk);
145 	reparent = (pll && !clk_is_match(pll, npll));
146 
147 	if (reparent) {
148 		ret = clk_set_parent(p, npll);
149 		if (ret < 0)
150 			dev_warn(dev, "failed to set parent:%d\n", ret);
151 	}
152 }
153 EXPORT_SYMBOL(fsl_asoc_reparent_pll_clocks);
154 
155 MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
156 MODULE_DESCRIPTION("Freescale ASoC utility code");
157 MODULE_LICENSE("GPL v2");
158