From 7524aaeff2fef8a41ee3d4c91fde72b013d8bab5 Mon Sep 17 00:00:00 2001
From: Eric Lee <eric.lee@embedian.com>
Date: Tue, 16 Jun 2015 01:02:24 +0800
Subject: [PATCH] Add U-Boot LVDS Backlight PWM Support
---
README | 4 ++
arch/arm/include/asm/arch-mx6/imx-regs.h | 17 +++++
board/embedian/smarcfimx6/smarcfimx6.c | 25 +++++--
drivers/Makefile | 1 +
drivers/pwm/Makefile | 13 ++++
drivers/pwm/pwm-imx-util.c | 73 +++++++++++++++++++++
drivers/pwm/pwm-imx-util.h | 16 +++++
drivers/pwm/pwm-imx.c | 109 +++++++++++++++++++++++++++++++
include/configs/smarcfimx6.h | 4 ++
9 files changed, 255 insertions(+), 7 deletions(-)
create mode 100644 drivers/pwm/Makefile
create mode 100644 drivers/pwm/pwm-imx-util.c
create mode 100644 drivers/pwm/pwm-imx-util.h
create mode 100644 drivers/pwm/pwm-imx.c
diff --git a/README b/README
index 25b22a3..857b5b7 100644
--- a/README
+++ b/README
@@ -1314,6 +1314,10 @@ The following options need to be configured:
CONFIG_SH_ETHER_CACHE_WRITEBACK
If this option is set, the driver enables cache flush.
+- PWM Support:
+ CONFIG_PWM_IMX
+ Support for PWM modul on the imx6.
+
- TPM Support:
CONFIG_TPM
Support TPM devices.
diff --git a/arch/arm/include/asm/arch-mx6/imx-regs.h b/arch/arm/include/asm/arch-mx6/imx-regs.h
index fd85803..57e10af 100644
--- a/arch/arm/include/asm/arch-mx6/imx-regs.h
+++ b/arch/arm/include/asm/arch-mx6/imx-regs.h
@@ -679,6 +679,23 @@ struct wdog_regs {
u16 wmcr; /* Miscellaneous Control */
};
+#define PWMCR_PRESCALER(x) (((x - 1) & 0xFFF) << 4)
+#define PWMCR_DOZEEN (1 << 24)
+#define PWMCR_WAITEN (1 << 23)
+#define PWMCR_DBGEN (1 << 22)
+#define PWMCR_CLKSRC_IPG_HIGH (2 << 16)
+#define PWMCR_CLKSRC_IPG (1 << 16)
+#define PWMCR_EN (1 << 0)
+
+struct pwm_regs {
+ u32 cr;
+ u32 sr;
+ u32 ir;
+ u32 sar;
+ u32 pr;
+ u32 cnr;
+};
+
struct dbg_monitor_regs {
u32 ctrl[4]; /* Control */
u32 master_en[4]; /* Master enable */
diff --git a/board/embedian/smarcfimx6/smarcfimx6.c b/board/embedian/smarcfimx6/smarcfimx6.c
index 1f4b626..0a158af 100644
--- a/board/embedian/smarcfimx6/smarcfimx6.c
+++ b/board/embedian/smarcfimx6/smarcfimx6.c
@@ -32,6 +32,7 @@
#include <ipu_pixfmt.h>
#include <asm/io.h>
#include <asm/arch/sys_proto.h>
+#include <pwm.h>
#ifdef CONFIG_SYS_I2C_MXC
#include <i2c.h>
#include <asm/imx-common/mxc_i2c.h>
@@ -835,11 +836,9 @@ static iomux_v3_cfg_t const backlight_pads[] = {
MX6_PAD_GPIO_0__GPIO1_IO00 | MUX_PAD_CTRL(NO_PAD_CTRL),
#define BACKLIGHT_EN IMX_GPIO_NR(1, 00)
/* PWM Backlight Control: S141 */
- MX6_PAD_GPIO_1__GPIO1_IO01 | MUX_PAD_CTRL(NO_PAD_CTRL),
-#define BACKLIGHT_PWM IMX_GPIO_NR(1, 01)
+
/* Backlight Enable for LVDS: S127 */
- /*MX6_PAD_GPIO_0__GPIO1_IO00 | MUX_PAD_CTRL(NO_PAD_CTRL),
-#define LVDS_BACKLIGHT_EN IMX_GPIO_NR(1, 00)*/
+ MX6_PAD_GPIO_1__PWM2_OUT | MUX_PAD_CTRL(NO_PAD_CTRL),
/* LCD VDD Enable(for parallel LCD): S133 */
MX6_PAD_GPIO_2__GPIO1_IO02 | MUX_PAD_CTRL(NO_PAD_CTRL),
#define LCD_VDD_EN IMX_GPIO_NR(1, 02)
@@ -1075,13 +1074,25 @@ static void setup_display(void)
writel(reg, &iomux->gpr[3]);
/* backlights off until needed */
- /*imx_iomux_v3_setup_multiple_pads(backlight_pads,
+ imx_iomux_v3_setup_multiple_pads(backlight_pads,
ARRAY_SIZE(backlight_pads));
- gpio_direction_input(BACKLIGHT_EN);*/
+ /*gpio_direction_input(BACKLIGHT_EN);*/
/* turn on backlight */
gpio_direction_output(BACKLIGHT_EN, 1);
- gpio_direction_output(BACKLIGHT_PWM, 1);
gpio_direction_output(LCD_VDD_EN, 1);
+ /* enable backlight PWM 2 */
+ if (pwm_init(1, 0, 0))
+ goto error;
+ /* duty cycle 500ns, period: 3000ns */
+ if (pwm_config(1, 1000, 3000))
+ goto error;
+ if (pwm_enable(1))
+ goto error;
+ return;
+
+error:
+ puts("error init pwm for backlight\n");
+ return;
}
#endif /* CONFIG_VIDEO_IPUV3 */
diff --git a/drivers/Makefile b/drivers/Makefile
index e103896..99d8b81 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -15,3 +15,4 @@ obj-y += video/
obj-y += watchdog/
obj-y += fastboot/
obj-$(CONFIG_QE) += qe/
+obj-y += pwm/
diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile
new file mode 100644
index 0000000..dd3a09a
--- /dev/null
+++ b/drivers/pwm/Makefile
@@ -0,0 +1,13 @@
+#
+# (C) Copyright 2006
+# Wolfgang Denk, DENX Software Engineering, wd at denx.de.
+#
+# (C) Copyright 2001
+# Erik Theisen, Wave 7 Optics, etheisen at mindspring.com.
+#
+# SPDX-License-Identifier: GPL-2.0+
+#
+
+#ccflags-y += -DDEBUG
+
+obj-$(CONFIG_PWM_IMX) += pwm-imx.o
diff --git a/drivers/pwm/pwm-imx-util.c b/drivers/pwm/pwm-imx-util.c
new file mode 100644
index 0000000..f1d0b35
--- /dev/null
+++ b/drivers/pwm/pwm-imx-util.c
@@ -0,0 +1,73 @@
+/*
+ * (C) Copyright 2014
+ * Heiko Schocher, DENX Software Engineering, hs@denx.de.
+ *
+ * Basic support for the pwm modul on imx6.
+ *
+ * Based on linux:drivers/pwm/pwm-imx.c
+ * from
+ * Sascha Hauer <s.hauer@pengutronix.de>
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <common.h>
+#include <div64.h>
+#include <asm/arch/imx-regs.h>
+
+/* pwm_id from 0..3 */
+struct pwm_regs *pwm_id_to_reg(int pwm_id)
+{
+ switch (pwm_id) {
+ case 0:
+ return (struct pwm_regs *)PWM1_BASE_ADDR;
+ break;
+ case 1:
+ return (struct pwm_regs *)PWM2_BASE_ADDR;
+ break;
+ case 2:
+ return (struct pwm_regs *)PWM3_BASE_ADDR;
+ break;
+ case 3:
+ return (struct pwm_regs *)PWM4_BASE_ADDR;
+ break;
+ default:
+ printf("unknown pwm_id: %d\n", pwm_id);
+ break;
+ }
+ return NULL;
+}
+
+int pwm_imx_get_parms(int period_ns, int duty_ns, unsigned long *period_c,
+ unsigned long *duty_c, unsigned long *prescale)
+{
+ unsigned long long c;
+
+ /*
+ * we have not yet a clock framework for imx6, so add the clock
+ * value here as a define. Replace it when we have the clock
+ * framework.
+ */
+ c = CONFIG_IMX6_PWM_PER_CLK;
+ c = c * period_ns;
+ do_div(c, 1000000000);
+ *period_c = c;
+
+ *prescale = *period_c / 0x10000 + 1;
+
+ *period_c /= *prescale;
+ c = (unsigned long long)(*period_c * duty_ns);
+ do_div(c, period_ns);
+ *duty_c = c;
+
+ /*
+ * according to imx pwm RM, the real period value should be
+ * PERIOD value in PWMPR plus 2.
+ */
+ if (*period_c > 2)
+ *period_c -= 2;
+ else
+ *period_c = 0;
+
+ return 0;
+}
diff --git a/drivers/pwm/pwm-imx-util.h b/drivers/pwm/pwm-imx-util.h
new file mode 100644
index 0000000..45465c4
--- /dev/null
+++ b/drivers/pwm/pwm-imx-util.h
@@ -0,0 +1,16 @@
+/*
+ * (C) Copyright 2014
+ * Heiko Schocher, DENX Software Engineering, hs@denx.de.
+ *
+ * Basic support for the pwm modul on imx6.
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#ifndef _pwm_imx_util_h_
+#define _pwm_imx_util_h_
+
+struct pwm_regs *pwm_id_to_reg(int pwm_id);
+int pwm_imx_get_parms(int period_ns, int duty_ns, unsigned long *period_c,
+ unsigned long *duty_c, unsigned long *prescale);
+#endif
diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
new file mode 100644
index 0000000..cb8f89f
--- /dev/null
+++ b/drivers/pwm/pwm-imx.c
@@ -0,0 +1,109 @@
+/*
+ * (C) Copyright 2014
+ * Heiko Schocher, DENX Software Engineering, hs at denx.de.
+ *
+ * Basic support for the pwm modul on imx6.
+ *
+ * Based on linux:drivers/pwm/pwm-imx.c
+ * from
+ * Sascha Hauer <s.hauer at pengutronix.de>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <div64.h>
+#include <pwm.h>
+#include <asm/arch/imx-regs.h>
+#include <asm/io.h>
+
+/* pwm_id from 0..3 */
+static struct pwm_regs *pwm_id_to_reg(int pwm_id)
+{
+ switch (pwm_id) {
+ case 0:
+ return (struct pwm_regs *)PWM1_BASE_ADDR;
+ break;
+ case 1:
+ return (struct pwm_regs *)PWM2_BASE_ADDR;
+ break;
+ case 2:
+ return (struct pwm_regs *)PWM3_BASE_ADDR;
+ break;
+ case 3:
+ return (struct pwm_regs *)PWM4_BASE_ADDR;
+ break;
+ default:
+ printf("unknown pwm_id: %d\n", pwm_id);
+ break;
+ }
+ return NULL;
+}
+
+int pwm_init(int pwm_id, int div, int invert)
+{
+ struct pwm_regs *pwm = (struct pwm_regs *)pwm_id_to_reg(pwm_id);
+
+ writel(0, &pwm->ir);
+ return 0;
+}
+
+int pwm_config(int pwm_id, int duty_ns, int period_ns)
+{
+ struct pwm_regs *pwm = (struct pwm_regs *)pwm_id_to_reg(pwm_id);
+ unsigned long long c;
+ unsigned long period_cycles, duty_cycles, prescale;
+ u32 cr;
+
+ /*
+ * we have not yet a clock framework for imx6, so add the clock
+ * value here as a define. Replace it when we have the clock
+ * framework.
+ */
+ c = CONFIG_IMX6_PWM_PER_CLK;
+ c = c * period_ns;
+ do_div(c, 1000000000);
+ period_cycles = c;
+
+ prescale = period_cycles / 0x10000 + 1;
+
+ period_cycles /= prescale;
+ c = (unsigned long long)period_cycles * duty_ns;
+ do_div(c, period_ns);
+ duty_cycles = c;
+
+ /*
+ * according to imx pwm RM, the real period value should be
+ * PERIOD value in PWMPR plus 2.
+ */
+ if (period_cycles > 2)
+ period_cycles -= 2;
+ else
+ period_cycles = 0;
+
+ cr = PWMCR_PRESCALER(prescale) |
+ PWMCR_DOZEEN | PWMCR_WAITEN |
+ PWMCR_DBGEN | PWMCR_CLKSRC_IPG_HIGH;
+
+ writel(cr, &pwm->cr);
+ /* set duty cycles */
+ writel(duty_cycles, &pwm->sar);
+ /* set period cycles */
+ writel(period_cycles, &pwm->pr);
+ return 0;
+}
+
+int pwm_enable(int pwm_id)
+{
+ struct pwm_regs *pwm = (struct pwm_regs *)pwm_id_to_reg(pwm_id);
+
+ setbits_le32(&pwm->cr, PWMCR_EN);
+ return 0;
+}
+
+void pwm_disable(int pwm_id)
+{
+ struct pwm_regs *pwm = (struct pwm_regs *)pwm_id_to_reg(pwm_id);
+
+ clrbits_le32(&pwm->cr, PWMCR_EN);
+}
diff --git a/include/configs/smarcfimx6.h b/include/configs/smarcfimx6.h
index 2774ca2..6940377 100644
--- a/include/configs/smarcfimx6.h
+++ b/include/configs/smarcfimx6.h
@@ -40,6 +40,10 @@
#include "smarcfimx6_common.h"
+/* PWM Configs */
+#define CONFIG_PWM_IMX
+#define CONFIG_IMX6_PWM_PER_CLK 66000000
+
/* USB Configs */
#define CONFIG_CMD_USB
#define CONFIG_USB_EHCI
--
1.9.1