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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* DaVinci DM816 AHCI SATA platform driver
*
* Copyright (C) 2017 BayLibre SAS
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/pm.h>
#include <linux/platform_device.h>
#include <linux/libata.h>
#include <linux/ahci_platform.h>
#include "ahci.h"
#define AHCI_DM816_DRV_NAME "ahci-dm816"
#define AHCI_DM816_PHY_ENPLL(x) ((x) << 0)
#define AHCI_DM816_PHY_MPY(x) ((x) << 1)
#define AHCI_DM816_PHY_LOS(x) ((x) << 12)
#define AHCI_DM816_PHY_RXCDR(x) ((x) << 13)
#define AHCI_DM816_PHY_RXEQ(x) ((x) << 16)
#define AHCI_DM816_PHY_TXSWING(x) ((x) << 23)
#define AHCI_DM816_P0PHYCR_REG 0x178
#define AHCI_DM816_P1PHYCR_REG 0x1f8
#define AHCI_DM816_PLL_OUT 1500000000LU
static const unsigned long pll_mpy_table[] = {
400, 500, 600, 800, 825, 1000, 1200,
1250, 1500, 1600, 1650, 2000, 2200, 2500
};
static int ahci_dm816_get_mpy_bits(unsigned long refclk_rate)
{
unsigned long pll_multiplier;
int i;
/*
* We need to determine the value of the multiplier (MPY) bits.
* In order to include the 8.25 multiplier we need to first divide
* the refclk rate by 100.
*/
pll_multiplier = AHCI_DM816_PLL_OUT / (refclk_rate / 100);
for (i = 0; i < ARRAY_SIZE(pll_mpy_table); i++) {
if (pll_mpy_table[i] == pll_multiplier)
return i;
}
/*
* We should have divided evenly - if not, return an invalid
* value.
*/
return -1;
}
static int ahci_dm816_phy_init(struct ahci_host_priv *hpriv, struct device *dev)
{
unsigned long refclk_rate;
int mpy;
u32 val;
/*
* We should have been supplied two clocks: the functional and
* keep-alive clock and the external reference clock. We need the
* rate of the latter to calculate the correct value of MPY bits.
*/
if (hpriv->n_clks < 2) {
dev_err(dev, "reference clock not supplied\n");
return -EINVAL;
}
refclk_rate = clk_get_rate(hpriv->clks[1].clk);
if ((refclk_rate % 100) != 0) {
dev_err(dev, "reference clock rate must be divisible by 100\n");
return -EINVAL;
}
mpy = ahci_dm816_get_mpy_bits(refclk_rate);
if (mpy < 0) {
dev_err(dev, "can't calculate the MPY bits value\n");
return -EINVAL;
}
/* Enable the PHY and configure the first HBA port. */
val = AHCI_DM816_PHY_MPY(mpy) | AHCI_DM816_PHY_LOS(1) |
AHCI_DM816_PHY_RXCDR(4) | AHCI_DM816_PHY_RXEQ(1) |
AHCI_DM816_PHY_TXSWING(3) | AHCI_DM816_PHY_ENPLL(1);
writel(val, hpriv->mmio + AHCI_DM816_P0PHYCR_REG);
/* Configure the second HBA port. */
val = AHCI_DM816_PHY_LOS(1) | AHCI_DM816_PHY_RXCDR(4) |
AHCI_DM816_PHY_RXEQ(1) | AHCI_DM816_PHY_TXSWING(3);
writel(val, hpriv->mmio + AHCI_DM816_P1PHYCR_REG);
return 0;
}
static int ahci_dm816_softreset(struct ata_link *link,
unsigned int *class, unsigned long deadline)
{
int pmp, ret;
pmp = sata_srst_pmp(link);
/*
* There's an issue with the SATA controller on DM816 SoC: if we
* enable Port Multiplier support, but the drive is connected directly
* to the board, it can't be detected. As a workaround: if PMP is
* enabled, we first call ahci_do_softreset() and pass it the result of
* sata_srst_pmp(). If this call fails, we retry with pmp = 0.
*/
ret = ahci_do_softreset(link, class, pmp, deadline, ahci_check_ready);
if (pmp && ret == -EBUSY)
return ahci_do_softreset(link, class, 0,
deadline, ahci_check_ready);
return ret;
}
static struct ata_port_operations ahci_dm816_port_ops = {
.inherits = &ahci_platform_ops,
.softreset = ahci_dm816_softreset,
};
static const struct ata_port_info ahci_dm816_port_info = {
.flags = AHCI_FLAG_COMMON,
.pio_mask = ATA_PIO4,
.udma_mask = ATA_UDMA6,
.port_ops = &ahci_dm816_port_ops,
};
static const struct scsi_host_template ahci_dm816_platform_sht = {
AHCI_SHT(AHCI_DM816_DRV_NAME),
};
static int ahci_dm816_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct ahci_host_priv *hpriv;
int rc;
hpriv = ahci_platform_get_resources(pdev, 0);
if (IS_ERR(hpriv))
return PTR_ERR(hpriv);
rc = ahci_platform_enable_resources(hpriv);
if (rc)
return rc;
rc = ahci_dm816_phy_init(hpriv, dev);
if (rc)
goto disable_resources;
rc = ahci_platform_init_host(pdev, hpriv,
&ahci_dm816_port_info,
&ahci_dm816_platform_sht);
if (rc)
goto disable_resources;
return 0;
disable_resources:
ahci_platform_disable_resources(hpriv);
return rc;
}
static SIMPLE_DEV_PM_OPS(ahci_dm816_pm_ops,
ahci_platform_suspend,
ahci_platform_resume);
static const struct of_device_id ahci_dm816_of_match[] = {
{ .compatible = "ti,dm816-ahci", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, ahci_dm816_of_match);
static struct platform_driver ahci_dm816_driver = {
.probe = ahci_dm816_probe,
.remove = ata_platform_remove_one,
.driver = {
.name = AHCI_DM816_DRV_NAME,
.of_match_table = ahci_dm816_of_match,
.pm = &ahci_dm816_pm_ops,
},
};
module_platform_driver(ahci_dm816_driver);
MODULE_DESCRIPTION("DaVinci DM816 AHCI SATA platform driver");
MODULE_AUTHOR("Bartosz Golaszewski <bgolaszewski@baylibre.com>");
MODULE_LICENSE("GPL");
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