drivers/power/power_spi.c

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