pruss mfd drivers

Programmable Realtime Unit (PRU) is basically a 32-bit RISC processor available within TI's DA8XX SOCs. It consists of local instruction and data RAM and also has access to SOC resources via a Switched Central Resource (SCR).

There are two PRU's available within DA8XX SOC's PRUSS, hence providing two execution cores. Devices/Protocols can be emulated on these utilizing either both or only one of the PRUs independently.

The rational behind the MFD driver being the fact that multiple devices can be implemented on the cores independently.
It's also possible, as in our case, to implement a single device on both the PRU's resulting in improved load sharing.

A detailed description is also available here:
http://processors.wiki.ti.com/index.php/Programmable_Realtime_Unit_Subsystem

version 1:
==========
* added pruss mfd driver.
* added pruss mfd board and platform changes.
* added pruss SocketCAN driver.
* added pruss SocketCAN board and platform changes.
* added pruss SocketCAN GPIOs.
* added previous review comments.

Subhasish Ghosh (9):
mfd: pruss mfd driver.
da850: pruss board specific additions.
da850: pruss platform specific additions.
can: pruss CAN driver.
da850: pruss CAN board specific additions.
da850: pruss CAN platform specific additions.
mfd: pruss CAN private data.
da850: pruss CAN board specific changes for gpios.
da850: pruss CAN platform specific changes for gpios.

 arch/arm/mach-davinci/board-da850-evm.c     |   75 ++
 arch/arm/mach-davinci/da850.c               |   12 +
 arch/arm/mach-davinci/devices-da8xx.c       |   65 ++
 arch/arm/mach-davinci/include/mach/da8xx.h  |    2 +
 arch/arm/mach-davinci/include/mach/mux.h    |    5 +
 drivers/mfd/Kconfig                         |   10 +
 drivers/mfd/Makefile                        |    1 +
 drivers/mfd/da8xx_pru.c                     |  403 +++++++++
 drivers/net/can/Kconfig                     |    1 +
 drivers/net/can/Makefile                    |    1 +
 drivers/net/can/da8xx_pruss/Kconfig         |   73 ++
 drivers/net/can/da8xx_pruss/Makefile        |    7 +
 drivers/net/can/da8xx_pruss/pruss_can.c     |  759 +++++++++++++++++
 drivers/net/can/da8xx_pruss/pruss_can_api.c | 1224 +++++++++++++++++++++++++++
 drivers/net/can/da8xx_pruss/pruss_can_api.h |  290 +++++++
 include/linux/mfd/pruss/da8xx_pru.h         |  106 +++
 include/linux/mfd/pruss/da8xx_prucore.h     |   74 ++
 17 files changed, 3108 insertions(+), 0 deletions(-)
 create mode 100644 drivers/mfd/da8xx_pru.c
 create mode 100644 drivers/net/can/da8xx_pruss/Kconfig
 create mode 100644 drivers/net/can/da8xx_pruss/Makefile
 create mode 100644 drivers/net/can/da8xx_pruss/pruss_can.c
 create mode 100644 drivers/net/can/da8xx_pruss/pruss_can_api.c
 create mode 100644 drivers/net/can/da8xx_pruss/pruss_can_api.h
 create mode 100644 include/linux/mfd/pruss/da8xx_pru.h
 create mode 100644 include/linux/mfd/pruss/da8xx_prucore.h

1.7.2.3

This patch adds the pruss MFD driver and associated include files.

---
 drivers/mfd/Kconfig                     |   10 +
 drivers/mfd/Makefile                    |    1 +
 drivers/mfd/da8xx_pru.c                 |  403 +++++++++++++++++++++++++++++++
 include/linux/mfd/pruss/da8xx_pru.h     |  102 ++++++++
 include/linux/mfd/pruss/da8xx_prucore.h |   74 ++++++
 5 files changed, 590 insertions(+), 0 deletions(-)
 create mode 100644 drivers/mfd/da8xx_pru.c
 create mode 100644 include/linux/mfd/pruss/da8xx_pru.h
 create mode 100644 include/linux/mfd/pruss/da8xx_prucore.h

index fd01836..6c437df 100644
@@ -81,6 +81,16 @@ config MFD_DM355EVM_MSP
 	  boards.  MSP430 firmware manages resets and power sequencing,
 	  inputs from buttons and the IR remote, LEDs, an RTC, and more.
 
+config MFD_DA8XX_PRUSS
+	tristate "Texas Instruments DA8XX PRUSS support"
+	depends on ARCH_DAVINCI && ARCH_DAVINCI_DA850
+	select MFD_CORE
+	help
+	    This driver provides support api's for the programmable
+		realtime unit (PRU) present on TI's da8xx processors. It
+		provides basic read, write, config, enable, disable
+		routines to facilitate devices emulated on it.
+
 config HTC_EGPIO
 	bool "HTC EGPIO support"
 	depends on GENERIC_HARDIRQS && GPIOLIB && ARM

index a54e2c7..670d6b0 100644
@@ -13,6 +13,7 @@ obj-$(CONFIG_HTC_PASIC3)	+= htc-pasic3.o
 obj-$(CONFIG_HTC_I2CPLD)	+= htc-i2cpld.o
 
 obj-$(CONFIG_MFD_DAVINCI_VOICECODEC)	+= davinci_voicecodec.o
+obj-$(CONFIG_MFD_DA8XX_PRUSS)	+= da8xx_pru.o
 obj-$(CONFIG_MFD_DM355EVM_MSP)	+= dm355evm_msp.o
 
 obj-$(CONFIG_MFD_STMPE)		+= stmpe.o

1.7.2.3

This patch adds board specific initializations and setup routines.

---
 arch/arm/mach-davinci/board-da850-evm.c |   28 ++++++++++++++++++++++++++++
 1 files changed, 28 insertions(+), 0 deletions(-)

index 11f986b..7938c6d 100644
@@ -1053,6 +1053,29 @@ static __init int da850_evm_init_cpufreq(void)
 static __init int da850_evm_init_cpufreq(void) { return 0; }
 #endif
 
+static struct da8xx_pruss_devices pruss_devices[] = {
+	{.dev_name = NULL,},
+};
+
+static int __init da8xx_evm_setup_pruss(void)
+{
+	u32 ret = 0;
+	u32 count;
+
+	for (count = 0; count < ARRAY_SIZE(pruss_devices); count++) {
+		if (pruss_devices[count].setup != NULL) {
+			ret = pruss_devices[count].setup();
+			if (ret) {
+				pr_warning("%s: %s init failed: %d\n", __func__,
+					pruss_devices[count].dev_name, ret);
+				return ret;
+			}
+		}
+	}
+
+	return da8xx_register_pruss(pruss_devices);
+}
+
 static __init void da850_evm_init(void)
 {
 	int ret;

@@ -1127,6 +1150,11 @@ static __init void da850_evm_init(void)
 
 	da8xx_register_mcasp(0, &da850_evm_snd_data);
 
+	ret = da8xx_evm_setup_pruss();
+	if (ret)
+		pr_warning("%s: pruss initialization failed: %d\n",
+				__func__, ret);
+
 	ret = davinci_cfg_reg_list(da850_lcdcntl_pins);
 	if (ret)
 		pr_warning("da850_evm_init: lcdcntl mux setup failed: %d\n",

1.7.2.3

Hello.

[...]

This patch adds the platform device and assignes the platform resources for the PRUSS mfd driver.

---
 arch/arm/mach-davinci/da850.c              |    7 +++
 arch/arm/mach-davinci/devices-da8xx.c      |   65 ++++++++++++++++++++++++++++
 arch/arm/mach-davinci/include/mach/da8xx.h |    2 +
 3 files changed, 74 insertions(+), 0 deletions(-)

index 3443d97..341d836 100644
@@ -238,6 +238,12 @@ static struct clk tptc2_clk = {
 	.flags		= ALWAYS_ENABLED,
 };
 
+static struct clk pruss_clk = {
+	.name		= "pruss",
+	.parent		= &pll0_sysclk2,
+	.lpsc		= DA8XX_LPSC0_DMAX,
+};
+
 static struct clk uart0_clk = {
 	.name		= "uart0",
 	.parent		= &pll0_sysclk2,

@@ -387,6 +393,7 @@ static struct clk_lookup da850_clks[] = {
 	CLK(NULL,		"tpcc1",	&tpcc1_clk),
 	CLK(NULL,		"tptc2",	&tptc2_clk),
 	CLK(NULL,		"uart0",	&uart0_clk),
+	CLK(NULL,		"pruss",	&pruss_clk),
 	CLK(NULL,		"uart1",	&uart1_clk),
 	CLK(NULL,		"uart2",	&uart2_clk),
 	CLK(NULL,		"aintc",	&aintc_clk),

index cfcb223..e5c178a 100644
@@ -15,6 +15,7 @@
 
 #include <linux/platform_device.h>
 #include <linux/davinci_emac.h>
+#include <linux/mfd/pruss/da8xx_pru.h>
 
 #include <mach/serial.h>
 #include <mach/edma.h>

@@ -81,6 +82,7 @@ int da8xx_register_watchdog(void);
 int da8xx_register_usb20(unsigned mA, unsigned potpgt);
 int da8xx_register_usb11(struct da8xx_ohci_root_hub *pdata);
 int da8xx_register_emac(void);
+int da8xx_register_pruss(struct da8xx_pruss_devices *);
 int da8xx_register_lcdc(struct da8xx_lcdc_platform_data *pdata);
 int da8xx_register_mmcsd0(struct davinci_mmc_config *config);
 int da850_register_mmcsd1(struct davinci_mmc_config *config);

1.7.2.3

Hello.

[...]

[...]

This patch adds support for the CAN device emulated on PRUSS.

---
 drivers/net/can/Kconfig                     |    1 +
 drivers/net/can/Makefile                    |    1 +
 drivers/net/can/da8xx_pruss/Kconfig         |   73 ++
 drivers/net/can/da8xx_pruss/Makefile        |    7 +
 drivers/net/can/da8xx_pruss/pruss_can.c     |  759 +++++++++++++++++
 drivers/net/can/da8xx_pruss/pruss_can_api.c | 1224 +++++++++++++++++++++++++++
 drivers/net/can/da8xx_pruss/pruss_can_api.h |  290 +++++++
 7 files changed, 2355 insertions(+), 0 deletions(-)
 create mode 100644 drivers/net/can/da8xx_pruss/Kconfig
 create mode 100644 drivers/net/can/da8xx_pruss/Makefile
 create mode 100644 drivers/net/can/da8xx_pruss/pruss_can.c
 create mode 100644 drivers/net/can/da8xx_pruss/pruss_can_api.c
 create mode 100644 drivers/net/can/da8xx_pruss/pruss_can_api.h

index d5a9db6..ae8f0f9 100644
@@ -112,6 +112,7 @@ config PCH_CAN
 	  This driver can access CAN bus.
 
 source "drivers/net/can/mscan/Kconfig"
+source "drivers/net/can/da8xx_pruss/Kconfig"
 
 source "drivers/net/can/sja1000/Kconfig"
 

index 07ca159..849cdbf 100644
@@ -14,6 +14,7 @@ obj-$(CONFIG_CAN_SJA1000)	+= sja1000/
 obj-$(CONFIG_CAN_MSCAN)		+= mscan/
 obj-$(CONFIG_CAN_AT91)		+= at91_can.o
 obj-$(CONFIG_CAN_TI_HECC)	+= ti_hecc.o
+obj-$(CONFIG_CAN_TI_DA8XX_PRU)	+= da8xx_pruss/
 obj-$(CONFIG_CAN_MCP251X)	+= mcp251x.o
 obj-$(CONFIG_CAN_BFIN)		+= bfin_can.o
 obj-$(CONFIG_CAN_JANZ_ICAN3)	+= janz-ican3.o

new file mode 100644
index 0000000..48f3055
@@ -0,0 +1,7 @@
+#
+# Makefile for CAN Lite emulation
+#
+can_emu-objs :=   pruss_can.o \
+                  pruss_can_api.o
+
+obj-$(CONFIG_CAN_TI_DA8XX_PRU)    += can_emu.o

1.7.2.3

Hi,

You should CC the netdev[1] and the socketcan mailing lists[2] on these patches.

Cheers
Detlev

[1] netdev at vger.kernel.org
[2] socketcan-core at lists.berlios.de

--
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HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-40 Fax: (+49)-8142-66989-80 Email: dzu at denx.de

This patch adds the pruss CAN pin mux and registers the device with the pruss mfd driver.

---
 arch/arm/mach-davinci/board-da850-evm.c |   40 ++++++++++++++++++++++++++++++-
 1 files changed, 39 insertions(+), 1 deletions(-)

index 7938c6d..285545f 100644
@@ -1053,8 +1053,46 @@ static __init int da850_evm_init_cpufreq(void)
 static __init int da850_evm_init_cpufreq(void) { return 0; }
 #endif
 
+const short da850_pruss_can_pins[] = {
+	DA850_PRUSS_PRU0_R31_0, DA850_PRUSS_PRU1_R30_15,
+	DA850_PRUSS_PRU1_R31_18,
+	-1
+};
+
+static int __init da850_evm_setup_pruss_can(void)
+{
+	int ret, val = 0;
+	void __iomem *cfg_chip3_base;
+
+	if (!machine_is_davinci_da850_evm())
+		return 0;
+
+	ret = davinci_cfg_reg_list(da850_pruss_can_pins);
+	if (ret)
+		pr_warning("%s: da850_pruss_can_pins mux setup "
+					"failed:%d\n", __func__, ret);
+	cfg_chip3_base = DA8XX_SYSCFG0_VIRT(DA8XX_CFGCHIP3_REG);
+	val = __raw_readl(cfg_chip3_base);
+	val |= BIT(3);
+	__raw_writel(val, cfg_chip3_base);
+
+	return ret;
+}
+
+static struct da8xx_pruss_can_data can_data = {
+	.version	= 1,
+};
+
 static struct da8xx_pruss_devices pruss_devices[] = {
-	{.dev_name = NULL,},
+	{
+		.dev_name	= "da8xx_pruss_can",
+		.pdata		= &can_data,
+		.pdata_size	= sizeof(can_data),
+		.setup		= da850_evm_setup_pruss_can,
+	},
+	{
+		.dev_name	= NULL,
+	},
 };
 
 static int __init da8xx_evm_setup_pruss(void)

1.7.2.3

Hello.

[...]

    Only da850_evm_pruss_can_pins[].

This patch adds the necessary pins for the pruss CAN.

---
 arch/arm/mach-davinci/da850.c            |    4 ++++
 arch/arm/mach-davinci/include/mach/mux.h |    4 ++++
 2 files changed, 8 insertions(+), 0 deletions(-)

index 341d836..11ce7ba 100644
@@ -565,6 +565,10 @@ static const struct mux_config da850_pins[] = {
 	MUX_CFG(DA850, EMA_CLK,		6,	0,	15,	1,	false)
 	MUX_CFG(DA850, EMA_WAIT_1,	6,	24,	15,	1,	false)
 	MUX_CFG(DA850, NEMA_CS_2,	7,	0,	15,	1,	false)
+	/* PRU functions for soft CAN */
+	MUX_CFG(DA850, PRUSS_PRU0_R31_0,	7,	28,	15,	0,	false)
+	MUX_CFG(DA850, PRUSS_PRU1_R30_15,	12,	0,	15,	4,	false)
+	MUX_CFG(DA850, PRUSS_PRU1_R31_18,	11,	20,	15,	0,	false)
 	/* GPIO function */
 	MUX_CFG(DA850, GPIO2_4,		6,	12,	15,	8,	false)
 	MUX_CFG(DA850, GPIO2_6,		6,	4,	15,	8,	false)

index 5d4e0fe..10f49f2 100644
@@ -906,6 +906,10 @@ enum davinci_da850_index {
 	DA850_EMA_CLK,
 	DA850_EMA_WAIT_1,
 	DA850_NEMA_CS_2,
+	/* PRU I/O */
+	DA850_PRUSS_PRU0_R31_0,
+	DA850_PRUSS_PRU1_R30_15,
+	DA850_PRUSS_PRU1_R31_18,
 
 	/* GPIO function */
 	DA850_GPIO2_4,

1.7.2.3

Hello.

[...]

This patch adds the PRUSS CAN data.

---
 include/linux/mfd/pruss/da8xx_pru.h |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

index 318dad8..2fa7ff5 100644
@@ -74,6 +74,10 @@ struct da8xx_pruss_devices {
 	int (*setup)(void);
 };
 
+struct da8xx_pruss_can_data {
+	u32 version;
+};
+
 u32 pruss_get_clk_freq(struct device *dev);
 
 u32 pruss_enable(struct device *dev, u8 pruss_num);

1.7.2.3

Hello.

[...]

This patch adds the GPIO modifications required for the pruss CAN.

---
 arch/arm/mach-davinci/board-da850-evm.c |   11 ++++++++++-
 1 files changed, 10 insertions(+), 1 deletions(-)

index 285545f..737df73 100644
@@ -45,6 +45,7 @@
 
 #define DA850_MMCSD_CD_PIN		GPIO_TO_PIN(4, 0)
 #define DA850_MMCSD_WP_PIN		GPIO_TO_PIN(4, 1)
+#define DA850_PRUSS_CAN_TRX_PIN	GPIO_TO_PIN(2, 0)
 
 #define DA850_MII_MDIO_CLKEN_PIN	GPIO_TO_PIN(2, 6)
 

@@ -1055,7 +1056,7 @@ static __init int da850_evm_init_cpufreq(void) { return 0; }
 
 const short da850_pruss_can_pins[] = {
 	DA850_PRUSS_PRU0_R31_0, DA850_PRUSS_PRU1_R30_15,
-	DA850_PRUSS_PRU1_R31_18,
+	DA850_PRUSS_PRU1_R31_18, DA850_GPIO2_0,
 	-1
 };
 

@@ -1076,6 +1077,14 @@ static int __init da850_evm_setup_pruss_can(void)
 	val |= BIT(3);
 	__raw_writel(val, cfg_chip3_base);
 
+	/* value = 0 to enable the CAN transceiver */
+	ret = gpio_request_one(DA850_PRUSS_CAN_TRX_PIN,
+					GPIOF_OUT_INIT_LOW, "pruss_can_en");
+	if (ret) {
+		pr_warning("Cannot setup GPIO %d\n", DA850_PRUSS_CAN_TRX_PIN);
+		gpio_free(DA850_PRUSS_CAN_TRX_PIN);
+	}
+
 	return ret;
 }
 

1.7.2.3

This patch adds the GPIOs for the pruss CAN device.

---
 arch/arm/mach-davinci/da850.c            |    1 +
 arch/arm/mach-davinci/include/mach/mux.h |    1 +
 2 files changed, 2 insertions(+), 0 deletions(-)

index 11ce7ba..9382b4f 100644
@@ -570,6 +570,7 @@ static const struct mux_config da850_pins[] = {
 	MUX_CFG(DA850, PRUSS_PRU1_R30_15,	12,	0,	15,	4,	false)
 	MUX_CFG(DA850, PRUSS_PRU1_R31_18,	11,	20,	15,	0,	false)
 	/* GPIO function */
+	MUX_CFG(DA850, GPIO2_0,		6,	28,	15,	8,	false)
 	MUX_CFG(DA850, GPIO2_4,		6,	12,	15,	8,	false)
 	MUX_CFG(DA850, GPIO2_6,		6,	4,	15,	8,	false)
 	MUX_CFG(DA850, GPIO2_8,		5,	28,	15,	8,	false)

index 10f49f2..85b3a0d 100644
@@ -912,6 +912,7 @@ enum davinci_da850_index {
 	DA850_PRUSS_PRU1_R31_18,
 
 	/* GPIO function */
+	DA850_GPIO2_0,
 	DA850_GPIO2_4,
 	DA850_GPIO2_6,
 	DA850_GPIO2_8,

1.7.2.3

[...]

The MFD and netdev lists need to be copied on this submission as this cannot be merged without an ack from the maintainers of those subsystems.

To automate copying the right folks on each patch, please use:

git-send-email --to <davinci list> --cc-cmd=scripts/get_maintainer.pl [...]

Thanks,
Sekhar

Please don't use get_maintainer.pl directly like this - you need to apply some thought and consideration to the results as it generates both false positives and false negatives.

Point taken. I usually do a --dry-run before actually sending just to verify the results.

Thanks,
Sekhar