[U-Boot] [PATCH v4] Add single register pin controller driver
Felix Brack
fb at ltec.ch
Wed Mar 22 10:26:44 UTC 2017
This patch adds a pin controller driver supporting devices
using a single configuration register per pin.
Signed-off-by: Felix Brack <fb at ltec.ch>
---
Changes in v4:
- add James Balean's modifications according to v3 to this patch
Changes in v3:
The use of pinctrl_ops.set_state_simple wile defining
CONFIG_PINCTRL_FULL seems to be wrong.
- use pinctrl_ops.set_state instead of pinctrl_ops.set_state_simple
Changes in v2:
- add a comment on function single_configure_pins() explaining
the function and its parameters
- use fdt_getprop() to simplify retrieval of property
'pinctrl-single,pins' from FDT
- change the return value of single_ofdata_to_platdata()
to -EINVAL in case of failure
- change the driver name from pcs_pinctrl to single_pinctrl
- minor reformatting to comply with coding style
drivers/pinctrl/Kconfig | 10 +++
drivers/pinctrl/Makefile | 1 +
drivers/pinctrl/pinctrl-single.c | 142 +++++++++++++++++++++++++++++++++++++++
3 files changed, 153 insertions(+)
create mode 100644 drivers/pinctrl/pinctrl-single.c
diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index efcb4c0..32bda65 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -175,6 +175,16 @@ config PIC32_PINCTRL
by a device tree node which contains both GPIO defintion and pin control
functions.
+config PINCTRL_SINGLE
+ bool "Single register pin-control and pin-multiplex driver"
+ depends on DM
+ help
+ This enables pinctrl driver for systems using a single register for
+ pin configuration and multiplexing. TI's AM335X SoCs are examples of
+ such systems.
+ Depending on the platform make sure to also enable OF_TRANSLATE and
+ eventually SPL_OF_TRANSLATE to get correct address translations.
+
endif
source "drivers/pinctrl/meson/Kconfig"
diff --git a/drivers/pinctrl/Makefile b/drivers/pinctrl/Makefile
index 512112a..f148f94 100644
--- a/drivers/pinctrl/Makefile
+++ b/drivers/pinctrl/Makefile
@@ -16,3 +16,4 @@ obj-$(CONFIG_PIC32_PINCTRL) += pinctrl_pic32.o
obj-$(CONFIG_PINCTRL_EXYNOS) += exynos/
obj-$(CONFIG_PINCTRL_MESON) += meson/
obj-$(CONFIG_PINCTRL_MVEBU) += mvebu/
+obj-$(CONFIG_PINCTRL_SINGLE) += pinctrl-single.o
diff --git a/drivers/pinctrl/pinctrl-single.c b/drivers/pinctrl/pinctrl-single.c
new file mode 100644
index 0000000..d2dcec0
--- /dev/null
+++ b/drivers/pinctrl/pinctrl-single.c
@@ -0,0 +1,142 @@
+/*
+ * Copyright (C) EETS GmbH, 2017, Felix Brack <f.brack at eets.ch>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm/device.h>
+#include <dm/pinctrl.h>
+#include <libfdt.h>
+#include <asm/io.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct single_pdata {
+ fdt_addr_t base; /* first configuration register */
+ int offset; /* index of last configuration register */
+ u32 mask; /* configuration-value mask bits */
+ int width; /* configuration register bit width */
+};
+
+struct single_fdt_pin_cfg {
+ fdt32_t reg; /* configuration register offset */
+ fdt32_t val; /* configuration register value */
+};
+
+/**
+ * single_configure_pins() - Configure pins based on FDT data
+ *
+ * @dev: Pointer to single pin configuration device which is the parent of
+ * the pins node holding the pin configuration data.
+ * @pins: Pointer to the first element of an array of register/value pairs
+ * of type 'struct single_fdt_pin_cfg'. Each such pair describes the
+ * the pin to be configured and the value to be used for configuration.
+ * This pointer points to a 'pinctrl-single,pins' property in the
+ * device-tree.
+ * @size: Size of the 'pins' array in bytes.
+ * The number of register/value pairs in the 'pins' array therefore
+ * equals to 'size / sizeof(struct single_fdt_pin_cfg)'.
+ */
+static int single_configure_pins(struct udevice *dev,
+ const struct single_fdt_pin_cfg *pins,
+ int size)
+{
+ struct single_pdata *pdata = dev->platdata;
+ int count = size / sizeof(struct single_fdt_pin_cfg);
+ int n, reg;
+ u32 val;
+
+ for (n = 0; n < count; n++) {
+ reg = fdt32_to_cpu(pins->reg);
+ if ((reg < 0) || (reg > pdata->offset)) {
+ dev_dbg(dev, " invalid register offset 0x%08x\n", reg);
+ pins++;
+ continue;
+ }
+ reg += pdata->base;
+ switch (pdata->width) {
+ case 32:
+ val = readl(reg) & ~pdata->mask;
+ val |= fdt32_to_cpu(pins->val) & pdata->mask;
+ writel(val, reg);
+ dev_dbg(dev, " reg/val 0x%08x/0x%08x\n",
+ reg, val);
+ break;
+ default:
+ dev_warn(dev, "unsupported register width %i\n",
+ pdata->width);
+ }
+ pins++;
+ }
+ return 0;
+}
+
+static int single_set_state(struct udevice *dev,
+ struct udevice *config)
+{
+ const void *fdt = gd->fdt_blob;
+ const struct single_fdt_pin_cfg *prop;
+ int len;
+
+ prop = fdt_getprop(fdt, config->of_offset, "pinctrl-single,pins", &len);
+ if (prop) {
+ dev_dbg(dev, "configuring pins for %s\n", config->name);
+ if (len % sizeof(struct single_fdt_pin_cfg)) {
+ dev_dbg(dev, " invalid pin configuration in fdt\n");
+ return -FDT_ERR_BADSTRUCTURE;
+ }
+ single_configure_pins(dev, prop, len);
+ len = 0;
+ }
+
+ return len;
+}
+
+static int single_ofdata_to_platdata(struct udevice *dev)
+{
+ fdt_addr_t addr;
+ u32 of_reg[2];
+ int res;
+ struct single_pdata *pdata = dev->platdata;
+
+ pdata->width = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
+ "pinctrl-single,register-width", 0);
+
+ res = fdtdec_get_int_array(gd->fdt_blob, dev->of_offset,
+ "reg", of_reg, 2);
+ if (res)
+ return res;
+ pdata->offset = of_reg[1] - pdata->width / 8;
+
+ addr = dev_get_addr(dev);
+ if (addr == FDT_ADDR_T_NONE) {
+ dev_dbg(dev, "no valid base register address\n");
+ return -EINVAL;
+ }
+ pdata->base = addr;
+
+ pdata->mask = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
+ "pinctrl-single,function-mask",
+ 0xffffffff);
+ return 0;
+}
+
+const struct pinctrl_ops single_pinctrl_ops = {
+ .set_state = single_set_state,
+};
+
+static const struct udevice_id single_pinctrl_match[] = {
+ { .compatible = "pinctrl-single" },
+ { /* sentinel */ }
+};
+
+U_BOOT_DRIVER(single_pinctrl) = {
+ .name = "single-pinctrl",
+ .id = UCLASS_PINCTRL,
+ .of_match = single_pinctrl_match,
+ .ops = &single_pinctrl_ops,
+ .flags = DM_FLAG_PRE_RELOC,
+ .platdata_auto_alloc_size = sizeof(struct single_pdata),
+ .ofdata_to_platdata = single_ofdata_to_platdata,
+};
--
2.7.4
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