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From 9fdab9bd6324314cbdfe96a6da5edef6c29ed5e6 Mon Sep 17 00:00:00 2001
From: Tim Gover <tim.gover@raspberrypi.org>
Date: Wed, 9 Jan 2019 14:43:36 +0000
Subject: [PATCH 549/806] pinctrl-bcm2835: Add support for BCM2838
GPIO configuration on BCM2838 is largely the same as BCM2835 except for
the pull up/down configuration. The old mechanism has been replaced
by new registers which don't require the fixed delay.
Detect BCN2838 at run-time and use the new mechanism. Backwards
compatibility for the device-tree configuration has been retained.
---
drivers/pinctrl/bcm/pinctrl-bcm2835.c | 58 ++++++++++++++++++++-------
1 file changed, 44 insertions(+), 14 deletions(-)
--- a/drivers/pinctrl/bcm/pinctrl-bcm2835.c
+++ b/drivers/pinctrl/bcm/pinctrl-bcm2835.c
@@ -67,6 +67,12 @@
#define GPPUD 0x94 /* Pin Pull-up/down Enable */
#define GPPUDCLK0 0x98 /* Pin Pull-up/down Enable Clock */
+/* 2711 has a different mechanism for pin pull-up/down/enable */
+#define GPPUPPDN0 0xe4 /* Pin pull-up/down for pins 15:0 */
+#define GPPUPPDN1 0xe8 /* Pin pull-up/down for pins 31:16 */
+#define GPPUPPDN2 0xec /* Pin pull-up/down for pins 47:32 */
+#define GPPUPPDN3 0xf0 /* Pin pull-up/down for pins 57:48 */
+
#define FSEL_REG(p) (GPFSEL0 + (((p) / 10) * 4))
#define FSEL_SHIFT(p) (((p) % 10) * 3)
#define GPIO_REG_OFFSET(p) ((p) / 32)
@@ -915,21 +921,45 @@ static void bcm2835_pull_config_set(stru
unsigned int pin, unsigned int arg)
{
u32 off, bit;
+ /* BCM2835, BCM2836 & BCM2837 return 'gpio' for this unused register */
+ int is_2835 = bcm2835_gpio_rd(pc, GPPUPPDN3) == 0x6770696f;
- off = GPIO_REG_OFFSET(pin);
- bit = GPIO_REG_SHIFT(pin);
-
- bcm2835_gpio_wr(pc, GPPUD, arg & 3);
- /*
- * BCM2835 datasheet say to wait 150 cycles, but not of what.
- * But the VideoCore firmware delay for this operation
- * based nearly on the same amount of VPU cycles and this clock
- * runs at 250 MHz.
- */
- udelay(1);
- bcm2835_gpio_wr(pc, GPPUDCLK0 + (off * 4), BIT(bit));
- udelay(1);
- bcm2835_gpio_wr(pc, GPPUDCLK0 + (off * 4), 0);
+ if (is_2835) {
+ off = GPIO_REG_OFFSET(pin);
+ bit = GPIO_REG_SHIFT(pin);
+ /*
+ * BCM2835 datasheet say to wait 150 cycles, but not of what.
+ * But the VideoCore firmware delay for this operation
+ * based nearly on the same amount of VPU cycles and this clock
+ * runs at 250 MHz.
+ */
+ bcm2835_gpio_wr(pc, GPPUD, arg & 3);
+ udelay(1);
+ bcm2835_gpio_wr(pc, GPPUDCLK0 + (off * 4), BIT(bit));
+ udelay(1);
+ bcm2835_gpio_wr(pc, GPPUDCLK0 + (off * 4), 0);
+ } else {
+ u32 reg;
+ int lsb;
+
+ off = (pin >> 4);
+ if (off > 3)
+ return;
+ lsb = (pin & 0xf) << 1;
+
+ /* The up/down semantics are reversed compared to BCM2835.
+ * Instead of updating all the device tree files, translate the
+ * values here.
+ */
+ if (arg == 2)
+ arg = 1;
+ else if (arg == 1)
+ arg = 2;
+ reg = bcm2835_gpio_rd(pc, GPPUPPDN0 + (off *4));
+ reg &= ~(0x3 << lsb);
+ reg |= (arg & 3) << lsb;
+ bcm2835_gpio_wr(pc, GPPUPPDN0 + (off * 4), reg);
+ }
}
static int bcm2835_pinconf_set(struct pinctrl_dev *pctldev,
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