[PATCH] can: flexcan: add vf61x support for flexcan

From: Stefan Agner
Date: Fri Jul 11 2014 - 07:00:34 EST

Extend FlexCAN driver to support Vybrid. Vybrids variant of the IP
has ECC support which is controlled through the memory error
control register (MECR). There is also an errata which leads to
false positive error detections (ID e5295). This patch disables
the memory error detection completely.

Also extend the clock control for FlexCAN to enable the clocks
in the Clock Divider (CCM_CSCDR2) register too.

Signed-off-by: Stefan Agner <stefan@xxxxxxxx>
---
Marc, this patch requires your patch regarding clock enable
for reading the ECR register:
http://marc.info/?l=linux-can&m=136861025221160&w=2
So I also tested that patch and it proved solving that issue
hence
Tested-By <stefan@xxxxxxxx>

I'm not sure whether its ok to include the device tree and
clock changes in one patch, let me know if you prefer that
splitted patches.

--
Stefan

arch/arm/boot/dts/vf610.dtsi | 25 ++++++++++++++-
arch/arm/mach-imx/clk-vf610.c | 6 ++--
drivers/net/can/flexcan.c | 73 +++++++++++++++++++++++++++++++++++++------
3 files changed, 92 insertions(+), 12 deletions(-)

diff --git a/arch/arm/boot/dts/vf610.dtsi b/arch/arm/boot/dts/vf610.dtsi
index 3fb127a..f38d8d8 100644
--- a/arch/arm/boot/dts/vf610.dtsi
+++ b/arch/arm/boot/dts/vf610.dtsi
@@ -14,6 +14,8 @@

/ {
aliases {
+ can0 = &can0;
+ can1 = &can1;
serial0 = &uart0;
serial1 = &uart1;
serial2 = &uart2;
@@ -103,6 +105,16 @@
<&clks VF610_CLK_DMAMUX1>;
};

+ can0: flexcan@40020000 {
+ compatible = "fsl,vf610-flexcan";
+ reg = <0x40020000 0x4000>;
+ interrupts = <0 58 IRQ_TYPE_LEVEL_HIGH>;
+ clocks = <&clks VF610_CLK_FLEXCAN0>,
+ <&clks VF610_CLK_FLEXCAN0>;
+ clock-names = "ipg", "per";
+ status = "disabled";
+ };
+
uart0: serial@40027000 {
compatible = "fsl,vf610-lpuart";
reg = <0x40027000 0x1000>;
@@ -362,7 +374,7 @@

esdhc1: esdhc@400b2000 {
compatible = "fsl,imx53-esdhc";
- reg = <0x400b2000 0x4000>;
+ reg = <0x400b2000 0x1000>;
interrupts = <0 28 0x04>;
clocks = <&clks VF610_CLK_IPG_BUS>,
<&clks VF610_CLK_PLATFORM_BUS>,
@@ -414,6 +426,17 @@
clock-names = "nfc";
status = "disabled";
};
+
+ can1: flexcan@400d4000 {
+ compatible = "fsl,vf610-flexcan";
+ reg = <0x400d4000 0x4000>;
+ interrupts = <0 59 IRQ_TYPE_LEVEL_HIGH>;
+ clocks = <&clks VF610_CLK_FLEXCAN1>,
+ <&clks VF610_CLK_FLEXCAN1>;
+ clock-names = "ipg", "per";
+ status = "disabled";
+ };
+
};
};
};
diff --git a/arch/arm/mach-imx/clk-vf610.c b/arch/arm/mach-imx/clk-vf610.c
index 22dc3ee..b12b888 100644
--- a/arch/arm/mach-imx/clk-vf610.c
+++ b/arch/arm/mach-imx/clk-vf610.c
@@ -295,8 +295,10 @@ static void __init vf610_clocks_init(struct device_node *ccm_node)

clk[VF610_CLK_ASRC] = imx_clk_gate2("asrc", "ipg_bus", CCM_CCGR4, CCM_CCGRx_CGn(1));

- clk[VF610_CLK_FLEXCAN0] = imx_clk_gate2("flexcan0", "ipg_bus", CCM_CCGR0, CCM_CCGRx_CGn(0));
- clk[VF610_CLK_FLEXCAN1] = imx_clk_gate2("flexcan1", "ipg_bus", CCM_CCGR9, CCM_CCGRx_CGn(4));
+ clk[VF610_CLK_FLEXCAN0] = imx_clk_gate("flexcan0_en", "ipg_bus", CCM_CSCDR2, 11);
+ clk[VF610_CLK_FLEXCAN0] = imx_clk_gate2("flexcan0", "flexcan0_en", CCM_CCGR0, CCM_CCGRx_CGn(0));
+ clk[VF610_CLK_FLEXCAN1] = imx_clk_gate("flexcan1_en", "ipg_bus", CCM_CSCDR2, 12);
+ clk[VF610_CLK_FLEXCAN1] = imx_clk_gate2("flexcan1", "flexcan1_en", CCM_CCGR9, CCM_CCGRx_CGn(4));

clk[VF610_CLK_DMAMUX0] = imx_clk_gate2("dmamux0", "platform_bus", CCM_CCGR0, CCM_CCGRx_CGn(4));
clk[VF610_CLK_DMAMUX1] = imx_clk_gate2("dmamux1", "platform_bus", CCM_CCGR0, CCM_CCGRx_CGn(5));
diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index f425ec2..1601247 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -92,6 +92,27 @@
#define FLEXCAN_CTRL_ERR_ALL \
(FLEXCAN_CTRL_ERR_BUS | FLEXCAN_CTRL_ERR_STATE)

+/* FLEXCAN control register 2 (CTRL2) bits */
+#define FLEXCAN_CRL2_ECRWRE BIT(29)
+#define FLEXCAN_CRL2_WRMFRZ BIT(28)
+#define FLEXCAN_CRL2_RFFN(x) (((x) & 0x0f) << 24)
+#define FLEXCAN_CRL2_TASD(x) (((x) & 0x1f) << 19)
+#define FLEXCAN_CRL2_MRP BIT(18)
+#define FLEXCAN_CRL2_RRS BIT(17)
+#define FLEXCAN_CRL2_EACEN BIT(16)
+
+/* FLEXCAN memory error control register (MECR) bits */
+#define FLEXCAN_MECR_ECRWRDIS BIT(31)
+#define FLEXCAN_MECR_HANCEI_MSK BIT(19)
+#define FLEXCAN_MECR_FANCEI_MSK BIT(18)
+#define FLEXCAN_MECR_CEI_MSK BIT(16)
+#define FLEXCAN_MECR_HAERRIE BIT(15)
+#define FLEXCAN_MECR_FAERRIE BIT(14)
+#define FLEXCAN_MECR_EXTERRIE BIT(13)
+#define FLEXCAN_MECR_RERRDIS BIT(9)
+#define FLEXCAN_MECR_ECCDIS BIT(8)
+#define FLEXCAN_MECR_NCEFAFRZ BIT(7)
+
/* FLEXCAN error and status register (ESR) bits */
#define FLEXCAN_ESR_TWRN_INT BIT(17)
#define FLEXCAN_ESR_RWRN_INT BIT(16)
@@ -150,18 +171,20 @@
* FLEXCAN hardware feature flags
*
* Below is some version info we got:
- * SOC Version IP-Version Glitch- [TR]WRN_INT
- * Filter? connected?
- * MX25 FlexCAN2 03.00.00.00 no no
- * MX28 FlexCAN2 03.00.04.00 yes yes
- * MX35 FlexCAN2 03.00.00.00 no no
- * MX53 FlexCAN2 03.00.00.00 yes no
- * MX6s FlexCAN3 10.00.12.00 yes yes
+ * SOC Version IP-Version Glitch- [TR]WRN_INT Memory err
+ * Filter? connected? detection
+ * MX25 FlexCAN2 03.00.00.00 no no no
+ * MX28 FlexCAN2 03.00.04.00 yes yes no
+ * MX35 FlexCAN2 03.00.00.00 no no no
+ * MX53 FlexCAN2 03.00.00.00 yes no no
+ * MX6s FlexCAN3 10.00.12.00 yes yes no
+ * VFxx FlexCAN3 ? no no yes
*
* Some SOCs do not have the RX_WARN & TX_WARN interrupt line connected.
*/
#define FLEXCAN_HAS_V10_FEATURES BIT(1) /* For core version >= 10 */
#define FLEXCAN_HAS_BROKEN_ERR_STATE BIT(2) /* [TR]WRN_INT not connected */
+#define FLEXCAN_HAS_MECR_FEATURES BIT(3) /* Memory error detection */

/* Structure of the message buffer */
struct flexcan_mb {
@@ -192,8 +215,11 @@ struct flexcan_regs {
u32 crcr; /* 0x44 */
u32 rxfgmask; /* 0x48 */
u32 rxfir; /* 0x4c */
- u32 _reserved3[12];
+ u32 _reserved3[12]; /* 0x50 */
struct flexcan_mb cantxfg[64];
+ u32 _reserved4[408];
+ u32 mecr; /* 0xae0 */
+ u32 erriar; /* 0xae4 */
};

struct flexcan_devtype_data {
@@ -223,6 +249,9 @@ static struct flexcan_devtype_data fsl_imx28_devtype_data;
static struct flexcan_devtype_data fsl_imx6q_devtype_data = {
.features = FLEXCAN_HAS_V10_FEATURES,
};
+static struct flexcan_devtype_data fsl_vf610_devtype_data = {
+ .features = FLEXCAN_HAS_V10_FEATURES | FLEXCAN_HAS_MECR_FEATURES,
+};

static const struct can_bittiming_const flexcan_bittiming_const = {
.name = DRV_NAME,
@@ -793,7 +822,7 @@ static int flexcan_chip_start(struct net_device *dev)
struct flexcan_priv *priv = netdev_priv(dev);
struct flexcan_regs __iomem *regs = priv->base;
int err;
- u32 reg_mcr, reg_ctrl;
+ u32 reg_mcr, reg_ctrl, reg_crl2, reg_mecr;

/* enable module */
err = flexcan_chip_enable(priv);
@@ -870,6 +899,31 @@ static int flexcan_chip_start(struct net_device *dev)
if (priv->devtype_data->features & FLEXCAN_HAS_V10_FEATURES)
flexcan_write(0x0, &regs->rxfgmask);

+ /*
+ * On Vybrid, disable memory error detection interrupts
+ * and freeze mode.
+ * This also works around errata e5295 which generates
+ * false positive memory errors and put the device in
+ * freeze mode.
+ */
+ if (priv->devtype_data->features & FLEXCAN_HAS_MECR_FEATURES) {
+ /*
+ * Follow the protocol as described in "Detection
+ * and Correction of Memory Errors" to write to
+ * MECR register
+ */
+ reg_crl2 = flexcan_read(&regs->crl2);
+ reg_crl2 |= FLEXCAN_CRL2_ECRWRE;
+ flexcan_write(reg_crl2, &regs->crl2);
+
+ reg_mecr = flexcan_read(&regs->mecr);
+ reg_mecr &= ~FLEXCAN_MECR_ECRWRDIS;
+ flexcan_write(reg_mecr, &regs->mecr);
+ reg_mecr &= ~(FLEXCAN_MECR_NCEFAFRZ | FLEXCAN_MECR_HANCEI_MSK |
+ FLEXCAN_MECR_FANCEI_MSK);
+ flexcan_write(reg_mecr, &regs->mecr);
+ }
+
err = flexcan_transceiver_enable(priv);
if (err)
goto out_chip_disable;
@@ -1080,6 +1134,7 @@ static const struct of_device_id flexcan_of_match[] = {
{ .compatible = "fsl,imx6q-flexcan", .data = &fsl_imx6q_devtype_data, },
{ .compatible = "fsl,imx28-flexcan", .data = &fsl_imx28_devtype_data, },
{ .compatible = "fsl,p1010-flexcan", .data = &fsl_p1010_devtype_data, },
+ { .compatible = "fsl,vf610-flexcan", .data = &fsl_vf610_devtype_data, },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, flexcan_of_match);
--
2.0.1

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