On 01/13/2017 06:38 AM, Bartosz Golaszewski wrote:
Currently the clock multiplier is hardcoded in the driver for
the da850-evm board. Make it configurable over DT, but keep the
previous value as default in case the property is missing.
Signed-off-by: Bartosz Golaszewski <[email protected]>
---
drivers/ata/ahci_da850.c | 83 +++++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 75 insertions(+), 8 deletions(-)
diff --git a/drivers/ata/ahci_da850.c b/drivers/ata/ahci_da850.c
index bb9eb4c..cd04caf 100644
--- a/drivers/ata/ahci_da850.c
+++ b/drivers/ata/ahci_da850.c
@@ -28,17 +28,70 @@
#define SATA_PHY_TXSWING(x) ((x) << 19)
#define SATA_PHY_ENPLL(x) ((x) << 31)
+struct da850_sata_mpy_mapping {
+ unsigned int multiplier;
+ unsigned int regval;
+};
+
+static const struct da850_sata_mpy_mapping da850_sata_mpy_table[] = {
+ {
+ .multiplier = 5,
+ .regval = 0x01,
+ },
+ {
+ .multiplier = 6,
+ .regval = 0x02,
+ },
+ {
+ .multiplier = 8,
+ .regval = 0x04,
+ },
+ {
+ .multiplier = 10,
+ .regval = 0x05,
+ },
+ {
+ .multiplier = 12,
+ .regval = 0x06,
+ },
+ /* TODO Add 12.5 multiplier. */
Looks like you should be using an enum here for the multiplier field.
+ {
+ .multiplier = 15,
+ .regval = 0x08,
+ },
+ {
+ .multiplier = 20,
+ .regval = 0x09,
+ },
+ {
+ .multiplier = 25,
+ .regval = 0x0a,
+ }
+};
+
+static const struct da850_sata_mpy_mapping *
+da850_sata_get_mpy(unsigned int multiplier)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(da850_sata_mpy_table); i++)
+ if (da850_sata_mpy_table[i].multiplier == multiplier)
+ return &da850_sata_mpy_table[i];
+
+ return NULL;
+}
+
/*
* 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.
+ * This is the default value suitable for the 100MHz crystal frequency
+ * used by DA850 EVM board, which doesn't use DT.
As I said in a reply on another patch, it seems like it would be better
to use a clock that represents the crystal and use clk_get_rate() and
calculate the multiplier from that.
For example, we have done something like this in
usb20_phy_clk_set_parent() in arch/arm/mach-davinci/usb-da8xx.c.
*/
-#define DA850_SATA_CLK_MULTIPLIER 7
+#define DA850_SATA_CLK_MULTIPLIER_DEFAULT 15
static void da850_sata_init(struct device *dev, void __iomem *pwrdn_reg,
- void __iomem *ahci_base)
+ void __iomem *ahci_base,
+ const struct da850_sata_mpy_mapping *mpy)
{
unsigned int val;
@@ -47,7 +100,7 @@ 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) |
+ val = SATA_PHY_MPY(mpy->regval) | SATA_PHY_LOS(1) |
SATA_PHY_RXCDR(4) | SATA_PHY_RXEQ(1) | SATA_PHY_TXSWING(3) |
SATA_PHY_ENPLL(1);
@@ -87,10 +140,12 @@ static struct scsi_host_template ahci_platform_sht = {
static int ahci_da850_probe(struct platform_device *pdev)
{
+ const struct da850_sata_mpy_mapping *mpy;
struct device *dev = &pdev->dev;
struct ahci_host_priv *hpriv;
- struct resource *res;
+ unsigned int multiplier;
void __iomem *pwrdn_reg;
+ struct resource *res;
int rc;
hpriv = ahci_platform_get_resources(pdev);
@@ -109,7 +164,19 @@ static int ahci_da850_probe(struct platform_device *pdev)
if (!pwrdn_reg)
goto disable_resources;
- da850_sata_init(dev, pwrdn_reg, hpriv->mmio);
+ rc = of_property_read_u32(dev->of_node,
+ "da850,clk_multiplier", &multiplier);
+ if (rc)
+ multiplier = DA850_SATA_CLK_MULTIPLIER_DEFAULT;
+
+ mpy = da850_sata_get_mpy(multiplier);
+ if (!mpy) {
+ dev_err(dev, "invalid multiplier value: %u\n", multiplier);
+ rc = -EINVAL;
+ goto disable_resources;
+ }
+
+ da850_sata_init(dev, pwrdn_reg, hpriv->mmio, mpy);
rc = ahci_platform_init_host(pdev, hpriv, &ahci_da850_port_info,
&ahci_platform_sht);
