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linux/drivers/phy/phy-qcom-apq8064-sata.c
Srinivas Kandagatla 175f02ebdf phy: qcom-apq8064: fix possible timeout without check 
This patch fixes a possible timeout in poll loop without actually
checking the register before return. In theory the there is a possibility
of loop being scheduled after a long lock/delay, which would then force
the loop to exit without actually checking the register.

Reported-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
2014-07-22 12:46:12 +05:30

290 lines
8.6 KiB
C
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/*
* Copyright (c) 2014, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/time.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/phy/phy.h>
/* PHY registers */
#define UNIPHY_PLL_REFCLK_CFG 0x000
#define UNIPHY_PLL_PWRGEN_CFG 0x014
#define UNIPHY_PLL_GLB_CFG 0x020
#define UNIPHY_PLL_SDM_CFG0 0x038
#define UNIPHY_PLL_SDM_CFG1 0x03C
#define UNIPHY_PLL_SDM_CFG2 0x040
#define UNIPHY_PLL_SDM_CFG3 0x044
#define UNIPHY_PLL_SDM_CFG4 0x048
#define UNIPHY_PLL_SSC_CFG0 0x04C
#define UNIPHY_PLL_SSC_CFG1 0x050
#define UNIPHY_PLL_SSC_CFG2 0x054
#define UNIPHY_PLL_SSC_CFG3 0x058
#define UNIPHY_PLL_LKDET_CFG0 0x05C
#define UNIPHY_PLL_LKDET_CFG1 0x060
#define UNIPHY_PLL_LKDET_CFG2 0x064
#define UNIPHY_PLL_CAL_CFG0 0x06C
#define UNIPHY_PLL_CAL_CFG8 0x08C
#define UNIPHY_PLL_CAL_CFG9 0x090
#define UNIPHY_PLL_CAL_CFG10 0x094
#define UNIPHY_PLL_CAL_CFG11 0x098
#define UNIPHY_PLL_STATUS 0x0C0
#define SATA_PHY_SER_CTRL 0x100
#define SATA_PHY_TX_DRIV_CTRL0 0x104
#define SATA_PHY_TX_DRIV_CTRL1 0x108
#define SATA_PHY_TX_IMCAL0 0x11C
#define SATA_PHY_TX_IMCAL2 0x124
#define SATA_PHY_RX_IMCAL0 0x128
#define SATA_PHY_EQUAL 0x13C
#define SATA_PHY_OOB_TERM 0x144
#define SATA_PHY_CDR_CTRL0 0x148
#define SATA_PHY_CDR_CTRL1 0x14C
#define SATA_PHY_CDR_CTRL2 0x150
#define SATA_PHY_CDR_CTRL3 0x154
#define SATA_PHY_PI_CTRL0 0x168
#define SATA_PHY_POW_DWN_CTRL0 0x180
#define SATA_PHY_POW_DWN_CTRL1 0x184
#define SATA_PHY_TX_DATA_CTRL 0x188
#define SATA_PHY_ALIGNP 0x1A4
#define SATA_PHY_TX_IMCAL_STAT 0x1E4
#define SATA_PHY_RX_IMCAL_STAT 0x1E8
#define UNIPHY_PLL_LOCK BIT(0)
#define SATA_PHY_TX_CAL BIT(0)
#define SATA_PHY_RX_CAL BIT(0)
/* default timeout set to 1 sec */
#define TIMEOUT_MS 10000
#define DELAY_INTERVAL_US 100
struct qcom_apq8064_sata_phy {
void __iomem *mmio;
struct clk *cfg_clk;
struct device *dev;
};
/* Helper function to do poll and timeout */
static int read_poll_timeout(void __iomem *addr, u32 mask)
{
unsigned long timeout = jiffies + msecs_to_jiffies(TIMEOUT_MS);
do {
if (readl_relaxed(addr) & mask)
return 0;
usleep_range(DELAY_INTERVAL_US, DELAY_INTERVAL_US + 50);
} while (!time_after(jiffies, timeout));
return (readl_relaxed(addr) & mask) ? 0 : -ETIMEDOUT;
}
static int qcom_apq8064_sata_phy_init(struct phy *generic_phy)
{
struct qcom_apq8064_sata_phy *phy = phy_get_drvdata(generic_phy);
void __iomem *base = phy->mmio;
int ret = 0;
/* SATA phy initialization */
writel_relaxed(0x01, base + SATA_PHY_SER_CTRL);
writel_relaxed(0xB1, base + SATA_PHY_POW_DWN_CTRL0);
/* Make sure the power down happens before power up */
mb();
usleep_range(10, 60);
writel_relaxed(0x01, base + SATA_PHY_POW_DWN_CTRL0);
writel_relaxed(0x3E, base + SATA_PHY_POW_DWN_CTRL1);
writel_relaxed(0x01, base + SATA_PHY_RX_IMCAL0);
writel_relaxed(0x01, base + SATA_PHY_TX_IMCAL0);
writel_relaxed(0x02, base + SATA_PHY_TX_IMCAL2);
/* Write UNIPHYPLL registers to configure PLL */
writel_relaxed(0x04, base + UNIPHY_PLL_REFCLK_CFG);
writel_relaxed(0x00, base + UNIPHY_PLL_PWRGEN_CFG);
writel_relaxed(0x0A, base + UNIPHY_PLL_CAL_CFG0);
writel_relaxed(0xF3, base + UNIPHY_PLL_CAL_CFG8);
writel_relaxed(0x01, base + UNIPHY_PLL_CAL_CFG9);
writel_relaxed(0xED, base + UNIPHY_PLL_CAL_CFG10);
writel_relaxed(0x02, base + UNIPHY_PLL_CAL_CFG11);
writel_relaxed(0x36, base + UNIPHY_PLL_SDM_CFG0);
writel_relaxed(0x0D, base + UNIPHY_PLL_SDM_CFG1);
writel_relaxed(0xA3, base + UNIPHY_PLL_SDM_CFG2);
writel_relaxed(0xF0, base + UNIPHY_PLL_SDM_CFG3);
writel_relaxed(0x00, base + UNIPHY_PLL_SDM_CFG4);
writel_relaxed(0x19, base + UNIPHY_PLL_SSC_CFG0);
writel_relaxed(0xE1, base + UNIPHY_PLL_SSC_CFG1);
writel_relaxed(0x00, base + UNIPHY_PLL_SSC_CFG2);
writel_relaxed(0x11, base + UNIPHY_PLL_SSC_CFG3);
writel_relaxed(0x04, base + UNIPHY_PLL_LKDET_CFG0);
writel_relaxed(0xFF, base + UNIPHY_PLL_LKDET_CFG1);
writel_relaxed(0x02, base + UNIPHY_PLL_GLB_CFG);
/* make sure global config LDO power down happens before power up */
mb();
writel_relaxed(0x03, base + UNIPHY_PLL_GLB_CFG);
writel_relaxed(0x05, base + UNIPHY_PLL_LKDET_CFG2);
/* PLL Lock wait */
ret = read_poll_timeout(base + UNIPHY_PLL_STATUS, UNIPHY_PLL_LOCK);
if (ret) {
dev_err(phy->dev, "poll timeout UNIPHY_PLL_STATUS\n");
return ret;
}
/* TX Calibration */
ret = read_poll_timeout(base + SATA_PHY_TX_IMCAL_STAT, SATA_PHY_TX_CAL);
if (ret) {
dev_err(phy->dev, "poll timeout SATA_PHY_TX_IMCAL_STAT\n");
return ret;
}
/* RX Calibration */
ret = read_poll_timeout(base + SATA_PHY_RX_IMCAL_STAT, SATA_PHY_RX_CAL);
if (ret) {
dev_err(phy->dev, "poll timeout SATA_PHY_RX_IMCAL_STAT\n");
return ret;
}
/* SATA phy calibrated succesfully, power up to functional mode */
writel_relaxed(0x3E, base + SATA_PHY_POW_DWN_CTRL1);
writel_relaxed(0x01, base + SATA_PHY_RX_IMCAL0);
writel_relaxed(0x01, base + SATA_PHY_TX_IMCAL0);
writel_relaxed(0x00, base + SATA_PHY_POW_DWN_CTRL1);
writel_relaxed(0x59, base + SATA_PHY_CDR_CTRL0);
writel_relaxed(0x04, base + SATA_PHY_CDR_CTRL1);
writel_relaxed(0x00, base + SATA_PHY_CDR_CTRL2);
writel_relaxed(0x00, base + SATA_PHY_PI_CTRL0);
writel_relaxed(0x00, base + SATA_PHY_CDR_CTRL3);
writel_relaxed(0x01, base + SATA_PHY_POW_DWN_CTRL0);
writel_relaxed(0x11, base + SATA_PHY_TX_DATA_CTRL);
writel_relaxed(0x43, base + SATA_PHY_ALIGNP);
writel_relaxed(0x04, base + SATA_PHY_OOB_TERM);
writel_relaxed(0x01, base + SATA_PHY_EQUAL);
writel_relaxed(0x09, base + SATA_PHY_TX_DRIV_CTRL0);
writel_relaxed(0x09, base + SATA_PHY_TX_DRIV_CTRL1);
return 0;
}
static int qcom_apq8064_sata_phy_exit(struct phy *generic_phy)
{
struct qcom_apq8064_sata_phy *phy = phy_get_drvdata(generic_phy);
void __iomem *base = phy->mmio;
/* Power down PHY */
writel_relaxed(0xF8, base + SATA_PHY_POW_DWN_CTRL0);
writel_relaxed(0xFE, base + SATA_PHY_POW_DWN_CTRL1);
/* Power down PLL block */
writel_relaxed(0x00, base + UNIPHY_PLL_GLB_CFG);
return 0;
}
static struct phy_ops qcom_apq8064_sata_phy_ops = {
.init = qcom_apq8064_sata_phy_init,
.exit = qcom_apq8064_sata_phy_exit,
.owner = THIS_MODULE,
};
static int qcom_apq8064_sata_phy_probe(struct platform_device *pdev)
{
struct qcom_apq8064_sata_phy *phy;
struct device *dev = &pdev->dev;
struct resource *res;
struct phy_provider *phy_provider;
struct phy *generic_phy;
int ret;
phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
if (!phy)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
phy->mmio = devm_ioremap_resource(dev, res);
if (IS_ERR(phy->mmio))
return PTR_ERR(phy->mmio);
generic_phy = devm_phy_create(dev, NULL, &qcom_apq8064_sata_phy_ops,
NULL);
if (IS_ERR(generic_phy)) {
dev_err(dev, "%s: failed to create phy\n", __func__);
return PTR_ERR(generic_phy);
}
phy->dev = dev;
phy_set_drvdata(generic_phy, phy);
platform_set_drvdata(pdev, phy);
phy->cfg_clk = devm_clk_get(dev, "cfg");
if (IS_ERR(phy->cfg_clk)) {
dev_err(dev, "Failed to get sata cfg clock\n");
return PTR_ERR(phy->cfg_clk);
}
ret = clk_prepare_enable(phy->cfg_clk);
if (ret)
return ret;
phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
if (IS_ERR(phy_provider)) {
clk_disable_unprepare(phy->cfg_clk);
dev_err(dev, "%s: failed to register phy\n", __func__);
return PTR_ERR(phy_provider);
}
return 0;
}
static int qcom_apq8064_sata_phy_remove(struct platform_device *pdev)
{
struct qcom_apq8064_sata_phy *phy = platform_get_drvdata(pdev);
clk_disable_unprepare(phy->cfg_clk);
return 0;
}
static const struct of_device_id qcom_apq8064_sata_phy_of_match[] = {
{ .compatible = "qcom,apq8064-sata-phy" },
{ },
};
MODULE_DEVICE_TABLE(of, qcom_apq8064_sata_phy_of_match);
static struct platform_driver qcom_apq8064_sata_phy_driver = {
.probe = qcom_apq8064_sata_phy_probe,
.remove = qcom_apq8064_sata_phy_remove,
.driver = {
.name = "qcom-apq8064-sata-phy",
.owner = THIS_MODULE,
.of_match_table = qcom_apq8064_sata_phy_of_match,
}
};
module_platform_driver(qcom_apq8064_sata_phy_driver);
MODULE_DESCRIPTION("QCOM apq8064 SATA PHY driver");
MODULE_LICENSE("GPL v2");
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