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path: root/drivers/ata/ahci_da850.c
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Diffstat (limited to 'drivers/ata/ahci_da850.c')
-rw-r--r--drivers/ata/ahci_da850.c175
1 files changed, 158 insertions, 17 deletions
diff --git a/drivers/ata/ahci_da850.c b/drivers/ata/ahci_da850.c
index 267a3d3e79f4..1a50cd3b4233 100644
--- a/drivers/ata/ahci_da850.c
+++ b/drivers/ata/ahci_da850.c
@@ -16,7 +16,8 @@
#include <linux/ahci_platform.h>
#include "ahci.h"
-#define DRV_NAME "ahci_da850"
+#define DRV_NAME "ahci_da850"
+#define HARDRESET_RETRIES 5
/* SATA PHY Control Register offset from AHCI base */
#define SATA_P0PHYCR_REG 0x178
@@ -28,17 +29,8 @@
#define SATA_PHY_TXSWING(x) ((x) << 19)
#define SATA_PHY_ENPLL(x) ((x) << 31)
-/*
- * The multiplier needed for 1.5GHz PLL output.
- *
- * NOTE: This is currently hardcoded to be suitable for 100MHz crystal
- * frequency (which is used by DA850 EVM board) and may need to be changed
- * if you would like to use this driver on some other board.
- */
-#define DA850_SATA_CLK_MULTIPLIER 7
-
static void da850_sata_init(struct device *dev, void __iomem *pwrdn_reg,
- void __iomem *ahci_base)
+ void __iomem *ahci_base, u32 mpy)
{
unsigned int val;
@@ -47,18 +39,122 @@ static void da850_sata_init(struct device *dev, void __iomem *pwrdn_reg,
val &= ~BIT(0);
writel(val, pwrdn_reg);
- val = SATA_PHY_MPY(DA850_SATA_CLK_MULTIPLIER + 1) | SATA_PHY_LOS(1) |
- SATA_PHY_RXCDR(4) | SATA_PHY_RXEQ(1) | SATA_PHY_TXSWING(3) |
- SATA_PHY_ENPLL(1);
+ val = SATA_PHY_MPY(mpy) | SATA_PHY_LOS(1) | SATA_PHY_RXCDR(4) |
+ SATA_PHY_RXEQ(1) | SATA_PHY_TXSWING(3) | SATA_PHY_ENPLL(1);
writel(val, ahci_base + SATA_P0PHYCR_REG);
}
+static u32 ahci_da850_calculate_mpy(unsigned long refclk_rate)
+{
+ u32 pll_output = 1500000000, needed;
+
+ /*
+ * We need to determine the value of the multiplier (MPY) bits.
+ * In order to include the 12.5 multiplier we need to first divide
+ * the refclk rate by ten.
+ *
+ * __div64_32() turned out to be unreliable, sometimes returning
+ * false results.
+ */
+ WARN((refclk_rate % 10) != 0, "refclk must be divisible by 10");
+ needed = pll_output / (refclk_rate / 10);
+
+ /*
+ * What we have now is (multiplier * 10).
+ *
+ * Let's determine the actual register value we need to write.
+ */
+
+ switch (needed) {
+ case 50:
+ return 0x1;
+ case 60:
+ return 0x2;
+ case 80:
+ return 0x4;
+ case 100:
+ return 0x5;
+ case 120:
+ return 0x6;
+ case 125:
+ return 0x7;
+ case 150:
+ return 0x8;
+ case 200:
+ return 0x9;
+ case 250:
+ return 0xa;
+ default:
+ /*
+ * We should have divided evenly - if not, return an invalid
+ * value.
+ */
+ return 0;
+ }
+}
+
+static int ahci_da850_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 da850 SoCs: 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 int ahci_da850_hardreset(struct ata_link *link,
+ unsigned int *class, unsigned long deadline)
+{
+ int ret, retry = HARDRESET_RETRIES;
+ bool online;
+
+ /*
+ * In order to correctly service the LCD controller of the da850 SoC,
+ * we increased the PLL0 frequency to 456MHz from the default 300MHz.
+ *
+ * This made the SATA controller unstable and the hardreset operation
+ * does not always succeed the first time. Before really giving up to
+ * bring up the link, retry the reset a couple times.
+ */
+ do {
+ ret = ahci_do_hardreset(link, class, deadline, &online);
+ if (online)
+ return ret;
+ } while (retry--);
+
+ return ret;
+}
+
+static struct ata_port_operations ahci_da850_port_ops = {
+ .inherits = &ahci_platform_ops,
+ .softreset = ahci_da850_softreset,
+ /*
+ * No need to override .pmp_softreset - it's only used for actual
+ * PMP-enabled ports.
+ */
+ .hardreset = ahci_da850_hardreset,
+ .pmp_hardreset = ahci_da850_hardreset,
+};
+
static const struct ata_port_info ahci_da850_port_info = {
.flags = AHCI_FLAG_COMMON,
.pio_mask = ATA_PIO4,
.udma_mask = ATA_UDMA6,
- .port_ops = &ahci_platform_ops,
+ .port_ops = &ahci_da850_port_ops,
};
static struct scsi_host_template ahci_platform_sht = {
@@ -69,14 +165,52 @@ static int ahci_da850_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct ahci_host_priv *hpriv;
- struct resource *res;
void __iomem *pwrdn_reg;
+ struct resource *res;
+ struct clk *clk;
+ u32 mpy;
int rc;
hpriv = ahci_platform_get_resources(pdev);
if (IS_ERR(hpriv))
return PTR_ERR(hpriv);
+ /*
+ * Internally ahci_platform_get_resources() calls clk_get(dev, NULL)
+ * when trying to obtain the functional clock. This SATA controller
+ * uses two clocks for which we specify two connection ids. If we don't
+ * have the functional clock at this point - call clk_get() again with
+ * con_id = "fck".
+ */
+ if (!hpriv->clks[0]) {
+ clk = clk_get(dev, "fck");
+ if (IS_ERR(clk))
+ return PTR_ERR(clk);
+
+ hpriv->clks[0] = clk;
+ }
+
+ /*
+ * The second clock used by ahci-da850 is the external REFCLK. If we
+ * didn't get it from ahci_platform_get_resources(), let's try to
+ * specify the con_id in clk_get().
+ */
+ if (!hpriv->clks[1]) {
+ clk = clk_get(dev, "refclk");
+ if (IS_ERR(clk)) {
+ dev_err(dev, "unable to obtain the reference clock");
+ return -ENODEV;
+ }
+
+ hpriv->clks[1] = clk;
+ }
+
+ mpy = ahci_da850_calculate_mpy(clk_get_rate(hpriv->clks[1]));
+ if (mpy == 0) {
+ dev_err(dev, "invalid REFCLK multiplier value: 0x%x", mpy);
+ return -EINVAL;
+ }
+
rc = ahci_platform_enable_resources(hpriv);
if (rc)
return rc;
@@ -89,7 +223,7 @@ static int ahci_da850_probe(struct platform_device *pdev)
if (!pwrdn_reg)
goto disable_resources;
- da850_sata_init(dev, pwrdn_reg, hpriv->mmio);
+ da850_sata_init(dev, pwrdn_reg, hpriv->mmio, mpy);
rc = ahci_platform_init_host(pdev, hpriv, &ahci_da850_port_info,
&ahci_platform_sht);
@@ -105,11 +239,18 @@ disable_resources:
static SIMPLE_DEV_PM_OPS(ahci_da850_pm_ops, ahci_platform_suspend,
ahci_platform_resume);
+static const struct of_device_id ahci_da850_of_match[] = {
+ { .compatible = "ti,da850-ahci", },
+ { },
+};
+MODULE_DEVICE_TABLE(of, ahci_da850_of_match);
+
static struct platform_driver ahci_da850_driver = {
.probe = ahci_da850_probe,
.remove = ata_platform_remove_one,
.driver = {
.name = DRV_NAME,
+ .of_match_table = ahci_da850_of_match,
.pm = &ahci_da850_pm_ops,
},
};