arch/arm/mach-omap2/am33xx/clk_synthesizer.c

   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  */
  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 #ifndef CONFIG_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  */
  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 #ifndef CONFIG_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  */
  94 int setup_clock_synthesizer(struct clk_synth *data)
  95 {
  96         int rc;
  97         u8 val = 0;
  98         struct udevice *dev = NULL;
  99 #ifndef CONFIG_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 }