can: mcp251x: Add device tree support

This patch adds Device Tree support to the Microchip MCP251X driver.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

2 files changed, 99 insertions, 25 deletions

diff --git a/Documentation/devicetree/bindings/net/can/microchip,mcp251x.txt b/Documentation/devicetree/bindings/net/can/microchip,mcp251x.txt
new file mode 100644
index 000000000000..ee3723beb701
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/can/microchip,mcp251x.txt
@@ -0,0 +1,25 @@
+* Microchip MCP251X stand-alone CAN controller device tree bindings
+
+Required properties:
+ - compatible: Should be one of the following:
+   - "microchip,mcp2510" for MCP2510.
+   - "microchip,mcp2515" for MCP2515.
+ - reg: SPI chip select.
+ - clocks: The clock feeding the CAN controller.
+ - interrupt-parent: The parent interrupt controller.
+ - interrupts: Should contain IRQ line for the CAN controller.
+
+Optional properties:
+ - vdd-supply: Regulator that powers the CAN controller.
+ - xceiver-supply: Regulator that powers the CAN transceiver.
+
+Example:
+        can0: can@1 {
+                compatible = "microchip,mcp2515";
+                reg = <1>;
+                clocks = <&clk24m>;
+                interrupt-parent = <&gpio4>;
+                interrupts = <13 0x2>;
+                vdd-supply = <&reg5v0>;
+                xceiver-supply = <&reg5v0>;
+        };
diff --git a/drivers/net/can/mcp251x.c b/drivers/net/can/mcp251x.c
index 88d3877b6277..cdb9808d12db 100644
--- a/drivers/net/can/mcp251x.c
+++ b/drivers/net/can/mcp251x.c
@@ -58,6 +58,7 @@
 #include <linux/can/dev.h>
 #include <linux/can/led.h>
 #include <linux/can/platform/mcp251x.h>
+#include <linux/clk.h>
 #include <linux/completion.h>
 #include <linux/delay.h>
 #include <linux/device.h>
@@ -68,6 +69,8 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/netdevice.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/spi/spi.h>
@@ -263,6 +266,7 @@ struct mcp251x_priv {
         int restart_tx;
         struct regulator *power;
         struct regulator *transceiver;
+        struct clk *clk;
 };
 
 #define MCP251X_IS(_model) \
@@ -994,22 +998,65 @@ static const struct net_device_ops mcp251x_netdev_ops = {
         .ndo_start_xmit = mcp251x_hard_start_xmit,
 };
 
+static const struct of_device_id mcp251x_of_match[] = {
+        {
+                .compatible     = "microchip,mcp2510",
+                .data           = (void *)CAN_MCP251X_MCP2510,
+        },
+        {
+                .compatible     = "microchip,mcp2515",
+                .data           = (void *)CAN_MCP251X_MCP2515,
+        },
+        { }
+};
+MODULE_DEVICE_TABLE(of, mcp251x_of_match);
+
+static const struct spi_device_id mcp251x_id_table[] = {
+        {
+                .name           = "mcp2510",
+                .driver_data    = (kernel_ulong_t)CAN_MCP251X_MCP2510,
+        },
+        {
+                .name           = "mcp2515",
+                .driver_data    = (kernel_ulong_t)CAN_MCP251X_MCP2515,
+        },
+        { }
+};
+MODULE_DEVICE_TABLE(spi, mcp251x_id_table);
+
 static int mcp251x_can_probe(struct spi_device *spi)
 {
+        const struct of_device_id *of_id = of_match_device(mcp251x_of_match,
+                                                           &spi->dev);
+        struct mcp251x_platform_data *pdata = dev_get_platdata(&spi->dev);
         struct net_device *net;
         struct mcp251x_priv *priv;
-        struct mcp251x_platform_data *pdata = dev_get_platdata(&spi->dev);
-        int ret = -ENODEV;
+        int freq, ret = -ENODEV;
+        struct clk *clk;
+
+        clk = devm_clk_get(&spi->dev, NULL);
+        if (IS_ERR(clk)) {
+                if (pdata)
+                        freq = pdata->oscillator_frequency;
+                else
+                        return PTR_ERR(clk);
+        } else {
+                freq = clk_get_rate(clk);
+        }
 
-        if (!pdata)
-                /* Platform data is required for osc freq */
-                goto error_out;
+        /* Sanity check */
+        if (freq < 1000000 || freq > 25000000)
+                return -ERANGE;
 
         /* Allocate can/net device */
         net = alloc_candev(sizeof(struct mcp251x_priv), TX_ECHO_SKB_MAX);
-        if (!net) {
-                ret = -ENOMEM;
-                goto error_alloc;
+        if (!net)
+                return -ENOMEM;
+
+        if (!IS_ERR(clk)) {
+                ret = clk_prepare_enable(clk);
+                if (ret)
+                        goto out_free;
         }
 
         net->netdev_ops = &mcp251x_netdev_ops;
@@ -1018,23 +1065,27 @@ static int mcp251x_can_probe(struct spi_device *spi)
         priv = netdev_priv(net);
         priv->can.bittiming_const = &mcp251x_bittiming_const;
         priv->can.do_set_mode = mcp251x_do_set_mode;
-        priv->can.clock.freq = pdata->oscillator_frequency / 2;
+        priv->can.clock.freq = freq / 2;
         priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
                 CAN_CTRLMODE_LOOPBACK | CAN_CTRLMODE_LISTENONLY;
-        priv->model = spi_get_device_id(spi)->driver_data;
+        if (of_id)
+                priv->model = (enum mcp251x_model)of_id->data;
+        else
+                priv->model = spi_get_device_id(spi)->driver_data;
         priv->net = net;
+        priv->clk = clk;
 
         priv->power = devm_regulator_get(&spi->dev, "vdd");
         priv->transceiver = devm_regulator_get(&spi->dev, "xceiver");
         if ((PTR_ERR(priv->power) == -EPROBE_DEFER) ||
             (PTR_ERR(priv->transceiver) == -EPROBE_DEFER)) {
                 ret = -EPROBE_DEFER;
-                goto error_power;
+                goto out_clk;
         }
 
         ret = mcp251x_power_enable(priv->power, 1);
         if (ret)
-                goto error_power;
+                goto out_clk;
 
         spi_set_drvdata(spi, priv);
 
@@ -1113,11 +1164,14 @@ error_probe:
                 dma_free_coherent(&spi->dev, PAGE_SIZE,
                                   priv->spi_tx_buf, priv->spi_tx_dma);
         mcp251x_power_enable(priv->power, 0);
-error_power:
+
+out_clk: