1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * clk-synthesizer.c
4 *
5 * Clock synthesizer apis
6 *
7 * Copyright (C) 2016, Texas Instruments, Incorporated - http://www.ti.com/
8 */
9
10
11 #include <common.h>
12 #include <asm/arch/clk_synthesizer.h>
13 #include <i2c.h>
14
15 /**
16 * clk_synthesizer_reg_read - Read register from synthesizer.
17 * dev: i2c bus device (not used if CONFIG_DM_I2C is not set)
18 * @addr: addr within the i2c device
19 * buf: Buffer to which value is to be read.
20 *
21 * For reading the register from this clock synthesizer, a command needs to
22 * be send along with enabling byte read more, and then read can happen.
23 * Returns 0 on success
24 */
clk_synthesizer_reg_read(struct udevice * dev,int addr,u8 * buf)25 static int clk_synthesizer_reg_read(struct udevice *dev, int addr, u8 *buf)
26 {
27 int rc;
28
29 /* Enable Bye read */
30 addr = addr | CLK_SYNTHESIZER_BYTE_MODE;
31
32 #if !CONFIG_IS_ENABLED(DM_I2C)
33 /* Send the command byte */
34 rc = i2c_write(CLK_SYNTHESIZER_I2C_ADDR, addr, 1, buf, 1);
35 if (rc)
36 printf("Failed to send command to clock synthesizer\n");
37
38 /* Read the Data */
39 return i2c_read(CLK_SYNTHESIZER_I2C_ADDR, addr, 1, buf, 1);
40 #else
41 /* Send the command byte */
42 rc = dm_i2c_reg_write(dev, addr, *buf);
43 if (rc)
44 printf("Failed to send command to clock synthesizer\n");
45
46 /* Read the Data */
47 rc = dm_i2c_reg_read(dev, addr);
48 if (rc < 0)
49 return rc;
50
51 *buf = (u8)rc;
52 return 0;
53 #endif
54
55 }
56
57 /**
58 * clk_synthesizer_reg_write - Write a value to register in synthesizer.
59 * dev: i2c bus device (not used if CONFIG_DM_I2C is not set)
60 * @addr: addr within the i2c device
61 * val: Value to be written in the addr.
62 *
63 * Enable the byte read mode in the address and start the i2c transfer.
64 * Returns 0 on success
65 */
clk_synthesizer_reg_write(struct udevice * dev,int addr,u8 val)66 static int clk_synthesizer_reg_write(struct udevice *dev, int addr, u8 val)
67 {
68 u8 cmd[2];
69 int rc = 0;
70
71 /* Enable byte write */
72 cmd[0] = addr | CLK_SYNTHESIZER_BYTE_MODE;
73 cmd[1] = val;
74
75 #if !CONFIG_IS_ENABLED(DM_I2C)
76 rc = i2c_write(CLK_SYNTHESIZER_I2C_ADDR, addr, 1, cmd, 2);
77 #else
78 rc = dm_i2c_write(dev, addr, cmd, 2);
79 #endif
80 if (rc)
81 printf("Clock synthesizer reg write failed at addr = 0x%x\n",
82 addr);
83 return rc;
84 }
85
86 /**
87 * setup_clock_syntherizer - Program the clock synthesizer to get the desired
88 * frequency.
89 * @data: Data containing the desired output
90 *
91 * This is a PLL-based high performance synthesizer which gives 3 outputs
92 * as per the PLL_DIV and load capacitor programmed.
93 */
setup_clock_synthesizer(struct clk_synth * data)94 int setup_clock_synthesizer(struct clk_synth *data)
95 {
96 int rc;
97 u8 val = 0;
98 struct udevice *dev = NULL;
99 #if !CONFIG_IS_ENABLED(DM_I2C)
100 rc = i2c_probe(CLK_SYNTHESIZER_I2C_ADDR);
101 if (rc) {
102 printf("i2c probe failed at address 0x%x\n",
103 CLK_SYNTHESIZER_I2C_ADDR);
104 return rc;
105 }
106 #else
107 rc = i2c_get_chip_for_busnum(0, CLK_SYNTHESIZER_I2C_ADDR, 1, &dev);
108 if (rc) {
109 printf("failed to get device for synthesizer at address 0x%x\n",
110 CLK_SYNTHESIZER_I2C_ADDR);
111 return rc;
112 }
113 #endif
114 rc = clk_synthesizer_reg_read(dev, CLK_SYNTHESIZER_ID_REG, &val);
115 if (val != data->id)
116 return rc;
117
118 /* Crystal Load capacitor selection */
119 rc = clk_synthesizer_reg_write(dev, CLK_SYNTHESIZER_XCSEL,
120 data->capacitor);
121 if (rc)
122 return rc;
123 rc = clk_synthesizer_reg_write(dev, CLK_SYNTHESIZER_MUX_REG,
124 data->mux);
125 if (rc)
126 return rc;
127 rc = clk_synthesizer_reg_write(dev, CLK_SYNTHESIZER_PDIV2_REG,
128 data->pdiv2);
129 if (rc)
130 return rc;
131 rc = clk_synthesizer_reg_write(dev, CLK_SYNTHESIZER_PDIV3_REG,
132 data->pdiv3);
133 if (rc)
134 return rc;
135
136 return 0;
137 }
138