drivers/power/power_spi.c

   1 /*
   2  * Copyright (C) 2011 Samsung Electronics
   3  * Lukasz Majewski <l.majewski@samsung.com>
   4  *
   5  * (C) Copyright 2010
   6  * Stefano Babic, DENX Software Engineering, sbabic@denx.de
   7  *
   8  * (C) Copyright 2008-2009 Freescale Semiconductor, Inc.
   9  *
  10  * SPDX-License-Identifier:     GPL-2.0+
  11  */
  12
  13 #include <common.h>
  14 #include <linux/types.h>
  15 #include <power/pmic.h>
  16 #include <spi.h>
  17
  18 static struct spi_slave *slave;
  19
  20 void pmic_spi_free(struct spi_slave *slave)
  21 {
  22         if (slave)
  23                 spi_free_slave(slave);
  24 }
  25
  26 struct spi_slave *pmic_spi_probe(struct pmic *p)
  27 {
  28         return spi_setup_slave(p->bus,
  29                 p->hw.spi.cs,
  30                 p->hw.spi.clk,
  31                 p->hw.spi.mode);
  32 }
  33
  34 static u32 pmic_reg(struct pmic *p, u32 reg, u32 *val, u32 write)
  35 {
  36         u32 pmic_tx, pmic_rx;
  37         u32 tmp;
  38
  39         if (!slave) {
  40                 slave = pmic_spi_probe(p);
  41
  42                 if (!slave)
  43                         return -1;
  44         }
  45
  46         if (check_reg(p, reg))
  47                 return -1;
  48
  49         if (spi_claim_bus(slave))
  50                 return -1;
  51
  52         pmic_tx = p->hw.spi.prepare_tx(reg, val, write);
  53
  54         tmp = cpu_to_be32(pmic_tx);
  55
  56         if (spi_xfer(slave, pmic_spi_bitlen, &tmp, &pmic_rx,
  57                         pmic_spi_flags)) {
  58                 spi_release_bus(slave);
  59                 return -1;
  60         }
  61
  62         if (write) {
  63                 pmic_tx = p->hw.spi.prepare_tx(reg, val, 0);
  64                 tmp = cpu_to_be32(pmic_tx);
  65                 if (spi_xfer(slave, pmic_spi_bitlen, &tmp, &pmic_rx,
  66                         pmic_spi_flags)) {
  67                         spi_release_bus(slave);
  68                         return -1;
  69                 }
  70         }
  71
  72         spi_release_bus(slave);
  73         *val = cpu_to_be32(pmic_rx);
  74
  75         return 0;
  76 }
  77
  78 int pmic_reg_write(struct pmic *p, u32 reg, u32 val)
  79 {
  80         if (pmic_reg(p, reg, &val, 1))
  81                 return -1;
  82
  83         return 0;
  84 }
  85
  86 int pmic_reg_read(struct pmic *p, u32 reg, u32 *val)
  87 {
  88         if (pmic_reg(p, reg, val, 0))
  89                 return -1;
  90
  91         return 0;
  92 }