266 lines
6.5 KiB
C
266 lines
6.5 KiB
C
/*
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* DaVinci DA850 AHCI SATA platform driver
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2, or (at your option)
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* any later version.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/pm.h>
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#include <linux/device.h>
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#include <linux/platform_device.h>
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#include <linux/libata.h>
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#include <linux/ahci_platform.h>
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#include "ahci.h"
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#define DRV_NAME "ahci_da850"
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#define HARDRESET_RETRIES 5
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/* SATA PHY Control Register offset from AHCI base */
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#define SATA_P0PHYCR_REG 0x178
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#define SATA_PHY_MPY(x) ((x) << 0)
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#define SATA_PHY_LOS(x) ((x) << 6)
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#define SATA_PHY_RXCDR(x) ((x) << 10)
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#define SATA_PHY_RXEQ(x) ((x) << 13)
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#define SATA_PHY_TXSWING(x) ((x) << 19)
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#define SATA_PHY_ENPLL(x) ((x) << 31)
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static void da850_sata_init(struct device *dev, void __iomem *pwrdn_reg,
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void __iomem *ahci_base, u32 mpy)
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{
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unsigned int val;
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/* Enable SATA clock receiver */
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val = readl(pwrdn_reg);
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val &= ~BIT(0);
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writel(val, pwrdn_reg);
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val = SATA_PHY_MPY(mpy) | SATA_PHY_LOS(1) | SATA_PHY_RXCDR(4) |
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SATA_PHY_RXEQ(1) | SATA_PHY_TXSWING(3) | SATA_PHY_ENPLL(1);
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writel(val, ahci_base + SATA_P0PHYCR_REG);
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}
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static u32 ahci_da850_calculate_mpy(unsigned long refclk_rate)
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{
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u32 pll_output = 1500000000, needed;
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/*
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* We need to determine the value of the multiplier (MPY) bits.
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* In order to include the 12.5 multiplier we need to first divide
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* the refclk rate by ten.
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*
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* __div64_32() turned out to be unreliable, sometimes returning
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* false results.
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*/
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WARN((refclk_rate % 10) != 0, "refclk must be divisible by 10");
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needed = pll_output / (refclk_rate / 10);
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/*
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* What we have now is (multiplier * 10).
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*
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* Let's determine the actual register value we need to write.
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*/
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switch (needed) {
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case 50:
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return 0x1;
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case 60:
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return 0x2;
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case 80:
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return 0x4;
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case 100:
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return 0x5;
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case 120:
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return 0x6;
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case 125:
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return 0x7;
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case 150:
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return 0x8;
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case 200:
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return 0x9;
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case 250:
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return 0xa;
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default:
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/*
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* We should have divided evenly - if not, return an invalid
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* value.
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*/
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return 0;
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}
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}
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static int ahci_da850_softreset(struct ata_link *link,
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unsigned int *class, unsigned long deadline)
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{
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int pmp, ret;
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pmp = sata_srst_pmp(link);
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/*
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* There's an issue with the SATA controller on da850 SoCs: if we
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* enable Port Multiplier support, but the drive is connected directly
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* to the board, it can't be detected. As a workaround: if PMP is
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* enabled, we first call ahci_do_softreset() and pass it the result of
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* sata_srst_pmp(). If this call fails, we retry with pmp = 0.
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*/
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ret = ahci_do_softreset(link, class, pmp, deadline, ahci_check_ready);
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if (pmp && ret == -EBUSY)
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return ahci_do_softreset(link, class, 0,
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deadline, ahci_check_ready);
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return ret;
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}
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static int ahci_da850_hardreset(struct ata_link *link,
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unsigned int *class, unsigned long deadline)
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{
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int ret, retry = HARDRESET_RETRIES;
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bool online;
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/*
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* In order to correctly service the LCD controller of the da850 SoC,
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* we increased the PLL0 frequency to 456MHz from the default 300MHz.
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*
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* This made the SATA controller unstable and the hardreset operation
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* does not always succeed the first time. Before really giving up to
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* bring up the link, retry the reset a couple times.
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*/
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do {
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ret = ahci_do_hardreset(link, class, deadline, &online);
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if (online)
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return ret;
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} while (retry--);
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return ret;
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}
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static struct ata_port_operations ahci_da850_port_ops = {
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.inherits = &ahci_platform_ops,
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.softreset = ahci_da850_softreset,
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/*
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* No need to override .pmp_softreset - it's only used for actual
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* PMP-enabled ports.
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*/
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.hardreset = ahci_da850_hardreset,
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.pmp_hardreset = ahci_da850_hardreset,
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};
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static const struct ata_port_info ahci_da850_port_info = {
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.flags = AHCI_FLAG_COMMON,
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.pio_mask = ATA_PIO4,
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.udma_mask = ATA_UDMA6,
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.port_ops = &ahci_da850_port_ops,
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};
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static struct scsi_host_template ahci_platform_sht = {
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AHCI_SHT(DRV_NAME),
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};
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static int ahci_da850_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct ahci_host_priv *hpriv;
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void __iomem *pwrdn_reg;
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struct resource *res;
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struct clk *clk;
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u32 mpy;
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int rc;
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hpriv = ahci_platform_get_resources(pdev, 0);
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if (IS_ERR(hpriv))
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return PTR_ERR(hpriv);
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/*
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* Internally ahci_platform_get_resources() calls clk_get(dev, NULL)
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* when trying to obtain the functional clock. This SATA controller
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* uses two clocks for which we specify two connection ids. If we don't
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* have the functional clock at this point - call clk_get() again with
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* con_id = "fck".
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*/
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if (!hpriv->clks[0]) {
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clk = clk_get(dev, "fck");
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if (IS_ERR(clk))
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return PTR_ERR(clk);
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hpriv->clks[0] = clk;
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}
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/*
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* The second clock used by ahci-da850 is the external REFCLK. If we
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* didn't get it from ahci_platform_get_resources(), let's try to
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* specify the con_id in clk_get().
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*/
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if (!hpriv->clks[1]) {
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clk = clk_get(dev, "refclk");
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if (IS_ERR(clk)) {
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dev_err(dev, "unable to obtain the reference clock");
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return -ENODEV;
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}
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hpriv->clks[1] = clk;
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}
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mpy = ahci_da850_calculate_mpy(clk_get_rate(hpriv->clks[1]));
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if (mpy == 0) {
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dev_err(dev, "invalid REFCLK multiplier value: 0x%x", mpy);
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return -EINVAL;
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}
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rc = ahci_platform_enable_resources(hpriv);
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if (rc)
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return rc;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
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if (!res) {
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rc = -ENODEV;
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goto disable_resources;
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}
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pwrdn_reg = devm_ioremap(dev, res->start, resource_size(res));
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if (!pwrdn_reg) {
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rc = -ENOMEM;
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goto disable_resources;
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}
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da850_sata_init(dev, pwrdn_reg, hpriv->mmio, mpy);
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rc = ahci_platform_init_host(pdev, hpriv, &ahci_da850_port_info,
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&ahci_platform_sht);
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if (rc)
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goto disable_resources;
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return 0;
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disable_resources:
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ahci_platform_disable_resources(hpriv);
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return rc;
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}
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static SIMPLE_DEV_PM_OPS(ahci_da850_pm_ops, ahci_platform_suspend,
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ahci_platform_resume);
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static const struct of_device_id ahci_da850_of_match[] = {
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{ .compatible = "ti,da850-ahci", },
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{ },
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};
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MODULE_DEVICE_TABLE(of, ahci_da850_of_match);
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static struct platform_driver ahci_da850_driver = {
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.probe = ahci_da850_probe,
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.remove = ata_platform_remove_one,
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.driver = {
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.name = DRV_NAME,
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.of_match_table = ahci_da850_of_match,
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.pm = &ahci_da850_pm_ops,
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},
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};
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module_platform_driver(ahci_da850_driver);
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MODULE_DESCRIPTION("DaVinci DA850 AHCI SATA platform driver");
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MODULE_AUTHOR("Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>");
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MODULE_LICENSE("GPL");
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