Technologic Systems provides an IP compatible with the SJA1000,
instantiated in an FPGA. Because of some bus widths issue, access to
registers is made through a "window" that works like this:
base + 0x0: address to read/write
base + 0x2: 8-bit register value
This commit adds a new compatible device, "technologic,sja1000", with
read and write functions using the window mechanism.
Signed-off-by: Damien Riegel <damien.rie...@savoirfairelinux.com>
---
drivers/net/can/sja1000/sja1000_platform.c | 47 ++++++++++++++++++++++++++++++
1 file changed, 47 insertions(+)
diff --git a/drivers/net/can/sja1000/sja1000_platform.c
b/drivers/net/can/sja1000/sja1000_platform.c
index e0572d0..bfb124d 100644
--- a/drivers/net/can/sja1000/sja1000_platform.c
+++ b/drivers/net/can/sja1000/sja1000_platform.c
@@ -45,6 +45,10 @@ struct sja1000_of_data {
int (*init)(struct sja1000_priv *priv, struct device_node *of);
};
+struct technologic_priv {
+ spinlock_t io_lock;
+};
+
static u8 sp_read_reg8(const struct sja1000_priv *priv, int reg)
{
return ioread8(priv->reg_base + reg);
@@ -75,6 +79,43 @@ static void sp_write_reg32(const struct sja1000_priv *priv,
int reg, u8 val)
iowrite8(val, priv->reg_base + reg * 4);
}
+static u8 technologic_read_reg16(const struct sja1000_priv *priv, int reg)
+{
+ struct technologic_priv *tp = priv->priv;
+ unsigned long flags;
+ u8 val;
+
+ spin_lock_irqsave(&tp->io_lock, flags);
+ iowrite16(reg, priv->reg_base + 0);
+ val = ioread16(priv->reg_base + 2);
+ spin_unlock_irqrestore(&tp->io_lock, flags);
+
+ return val;
+}
+
+static void technologic_write_reg16(const struct sja1000_priv *priv,
+ int reg, u8 val)
+{
+ struct technologic_priv *tp = priv->priv;
+ unsigned long flags;
+
+ spin_lock_irqsave(&tp->io_lock, flags);
+ iowrite16(reg, priv->reg_base + 0);
+ iowrite16(val, priv->reg_base + 2);
+ spin_unlock_irqrestore(&tp->io_lock, flags);
+}
+
+static int technologic_init(struct sja1000_priv *priv, struct device_node *of)
+{
+ struct technologic_priv *tp = priv->priv;
+
+ priv->read_reg = technologic_read_reg16;
+ priv->write_reg = technologic_write_reg16;
+ spin_lock_init(&tp->io_lock);
+
+ return 0;
+}
+
static void sp_populate(struct sja1000_priv *priv,
struct sja1000_platform_data *pdata,
unsigned long resource_mem_flags)
@@ -255,8 +296,14 @@ static int sp_remove(struct platform_device *pdev)
return 0;
}
+struct sja1000_of_data technologic_data = {
+ .priv_sz = sizeof(struct technologic_priv),
+ .init = technologic_init,
+};
+
static const struct of_device_id sp_of_table[] = {
{.compatible = "nxp,sja1000"},
+ {.compatible = "technologic,sja1000", .data = &technologic_data},
{},
};
MODULE_DEVICE_TABLE(of, sp_of_table);
--
2.5.0
--
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