--- /dev/null
+/*
+ * DaVinci DM816 AHCI SATA platform driver
+ *
+ * Copyright (C) 2017 BayLibre SAS
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ */
+
+#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->clks[1]) {
+ dev_err(dev, "reference clock not supplied\n");
+ return -EINVAL;
+ }
+
+ refclk_rate = clk_get_rate(hpriv->clks[1]);
+ 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 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);
+ 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", },
+ { },
+};
+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");
projects / linux-2.6-microblaze.git / blobdiff