This adds a driver that supports the GPIO block found in
MStar/SigmaStar ARMv7 SoCs.
The controller seems to support 128 lines but where they
are wired up differs between chips and no currently known
chip uses anywhere near 128 lines so there needs to be some
per-chip data to collect together what lines actually have
physical pins attached and map the right names to them.
The core peripherals seem to use the same lines on the
currently known chips but the lines used for the sensor
interface, lcd controller etc pins seem to be totally
different between the infinity and mercury chips
The code tries to collect all of the re-usable names,
offsets etc together so that it's easy to build the extra
per-chip data for other chips in the future.
So far this only supports the MSC313 and MSC313E chips.
Support for the SSC8336N (mercury5) is trivial to add once
all of the lines have been mapped out.
Signed-off-by: Daniel Palmer <[email protected]>
---
MAINTAINERS | 1 +
drivers/gpio/Kconfig | 9 +
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-msc313.c | 406 +++++++++++++++++++++++++++++++++++++
4 files changed, 417 insertions(+)
create mode 100644 drivers/gpio/gpio-msc313.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 102aedca81dc..86b16452c505 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2133,6 +2133,7 @@ F: Documentation/devicetree/bindings/arm/mstar/*
F: Documentation/devicetree/bindings/gpio/mstar,msc313-gpio.yaml
F: arch/arm/boot/dts/mstar-*
F: arch/arm/mach-mstar/
+F: drivers/gpio/gpio-msc313.c
F: include/dt-bindings/gpio/msc313-gpio.h
ARM/NEC MOBILEPRO 900/c MACHINE SUPPORT
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 5d4de5cd6759..64160cc0a477 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -737,6 +737,15 @@ config GPIO_AMD_FCH
Note: This driver doesn't registers itself automatically, as it
needs to be provided with platform specific configuration.
(See eg. CONFIG_PCENGINES_APU2.)
+
+config GPIO_MSC313
+ bool "MStar MSC313 GPIO support"
+ default y if ARCH_MSTARV7
+ depends on ARCH_MSTARV7
+ select GPIOLIB_IRQCHIP
+ help
+ Say Y here to support GPIO on MStar MSC313 and later SoCs.
+
endmenu
menu "Port-mapped I/O GPIO drivers"
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 09dada80ac34..b6c116a7c785 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -101,6 +101,7 @@ obj-$(CONFIG_GPIO_MOCKUP) += gpio-mockup.o
obj-$(CONFIG_GPIO_MOXTET) += gpio-moxtet.o
obj-$(CONFIG_GPIO_MPC5200) += gpio-mpc5200.o
obj-$(CONFIG_GPIO_MPC8XXX) += gpio-mpc8xxx.o
+obj-$(CONFIG_GPIO_MSC313) += gpio-msc313.o
obj-$(CONFIG_GPIO_MSIC) += gpio-msic.o
obj-$(CONFIG_GPIO_MT7621) += gpio-mt7621.o
obj-$(CONFIG_GPIO_MVEBU) += gpio-mvebu.o
diff --git a/drivers/gpio/gpio-msc313.c b/drivers/gpio/gpio-msc313.c
new file mode 100644
index 000000000000..2751ee520b86
--- /dev/null
+++ b/drivers/gpio/gpio-msc313.c
@@ -0,0 +1,406 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020 Daniel Palmer<[email protected]>
+ */
+
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/gpio/driver.h>
+
+#include <dt-bindings/gpio/msc313-gpio.h>
+#include <dt-bindings/interrupt-controller/arm-gic.h>
+
+#define DRIVER_NAME "gpio-msc313"
+
+#define MSC313_GPIO_IN BIT(0)
+#define MSC313_GPIO_OUT BIT(4)
+#define MSC313_GPIO_OEN BIT(5)
+
+/* These bits need to be saved to correctly restore the
+ * gpio state when resuming from suspend to memory.
+ */
+#define MSC313_GPIO_BITSTOSAVE (MSC313_GPIO_OUT | MSC313_GPIO_OEN)
+
+#define FUART_NAMES \
+ MSC313_PINNAME_FUART_RX, \
+ MSC313_PINNAME_FUART_TX, \
+ MSC313_PINNAME_FUART_CTS, \
+ MSC313_PINNAME_FUART_RTS
+
+#define OFF_FUART_RX 0x50
+#define OFF_FUART_TX 0x54
+#define OFF_FUART_CTS 0x58
+#define OFF_FUART_RTS 0x5c
+
+#define FUART_OFFSETS \
+ OFF_FUART_RX, \
+ OFF_FUART_TX, \
+ OFF_FUART_CTS, \
+ OFF_FUART_RTS
+
+#define SR_NAMES \
+ MSC313_PINNAME_SR_IO2, \
+ MSC313_PINNAME_SR_IO3, \
+ MSC313_PINNAME_SR_IO4, \
+ MSC313_PINNAME_SR_IO5, \
+ MSC313_PINNAME_SR_IO6, \
+ MSC313_PINNAME_SR_IO7, \
+ MSC313_PINNAME_SR_IO8, \
+ MSC313_PINNAME_SR_IO9, \
+ MSC313_PINNAME_SR_IO10, \
+ MSC313_PINNAME_SR_IO11, \
+ MSC313_PINNAME_SR_IO12, \
+ MSC313_PINNAME_SR_IO13, \
+ MSC313_PINNAME_SR_IO14, \
+ MSC313_PINNAME_SR_IO15, \
+ MSC313_PINNAME_SR_IO16, \
+ MSC313_PINNAME_SR_IO17
+
+#define OFF_SR_IO2 0x88
+#define OFF_SR_IO3 0x8c
+#define OFF_SR_IO4 0x90
+#define OFF_SR_IO5 0x94
+#define OFF_SR_IO6 0x98
+#define OFF_SR_IO7 0x9c
+#define OFF_SR_IO8 0xa0
+#define OFF_SR_IO9 0xa4
+#define OFF_SR_IO10 0xa8
+#define OFF_SR_IO11 0xac
+#define OFF_SR_IO12 0xb0
+#define OFF_SR_IO13 0xb4
+#define OFF_SR_IO14 0xb8
+#define OFF_SR_IO15 0xbc
+#define OFF_SR_IO16 0xc0
+#define OFF_SR_IO17 0xc4
+
+#define SR_OFFSETS \
+ OFF_SR_IO2, \
+ OFF_SR_IO3, \
+ OFF_SR_IO4, \
+ OFF_SR_IO5, \
+ OFF_SR_IO6, \
+ OFF_SR_IO7, \
+ OFF_SR_IO8, \
+ OFF_SR_IO9, \
+ OFF_SR_IO10, \
+ OFF_SR_IO11, \
+ OFF_SR_IO12, \
+ OFF_SR_IO13, \
+ OFF_SR_IO14, \
+ OFF_SR_IO15, \
+ OFF_SR_IO16, \
+ OFF_SR_IO17
+
+#define SD_NAMES \
+ MSC313_PINNAME_SD_CLK, \
+ MSC313_PINNAME_SD_CMD, \
+ MSC313_PINNAME_SD_D0, \
+ MSC313_PINNAME_SD_D1, \
+ MSC313_PINNAME_SD_D2, \
+ MSC313_PINNAME_SD_D3
+
+#define OFF_SD_CLK 0x140
+#define OFF_SD_CMD 0x144
+#define OFF_SD_D0 0x148
+#define OFF_SD_D1 0x14c
+#define OFF_SD_D2 0x150
+#define OFF_SD_D3 0x154
+
+#define SD_OFFSETS \
+ OFF_SD_CLK, \
+ OFF_SD_CMD, \
+ OFF_SD_D0, \
+ OFF_SD_D1, \
+ OFF_SD_D2, \
+ OFF_SD_D3
+
+#define I2C1_NAMES \
+ MSC313_PINNAME_I2C1_SCL, \
+ MSC313_PINNAME_I2C1_SCA
+
+#define OFF_I2C1_SCL 0x188
+#define OFF_I2C1_SCA 0x18c
+
+#define I2C1_OFFSETS \
+ OFF_I2C1_SCL, \
+ OFF_I2C1_SCA
+
+#define SPI0_NAMES \
+ MSC313_PINNAME_SPI0_CZ, \
+ MSC313_PINNAME_SPI0_CK, \
+ MSC313_PINNAME_SPI0_DI, \
+ MSC313_PINNAME_SPI0_DO
+
+#define OFF_SPI0_CZ 0x1c0
+#define OFF_SPI0_CK 0x1c4
+#define OFF_SPI0_DI 0x1c8
+#define OFF_SPI0_DO 0x1cc
+
+#define SPI0_OFFSETS \
+ OFF_SPI0_CZ, \
+ OFF_SPI0_CK, \
+ OFF_SPI0_DI, \
+ OFF_SPI0_DO
+
+struct msc313_gpio_data {
+ const char * const *names;
+ const unsigned int *offsets;
+ const unsigned int num;
+};
+
+#define MSC313_GPIO_CHIPDATA(_chip) \
+static const struct msc313_gpio_data _chip##_data = { \
+ .names = _chip##_names, \
+ .offsets = _chip##_offsets, \
+ .num = ARRAY_SIZE(_chip##_offsets), \
+}
+
+#ifdef CONFIG_MACH_INFINITY
+static const char * const msc313_names[] = {
+ FUART_NAMES,
+ SR_NAMES,
+ SD_NAMES,
+ I2C1_NAMES,
+ SPI0_NAMES,
+};
+
+static const unsigned int msc313_offsets[] = {
+ FUART_OFFSETS,
+ SR_OFFSETS,
+ SD_OFFSETS,
+ I2C1_OFFSETS,
+ SPI0_OFFSETS,
+};
+
+MSC313_GPIO_CHIPDATA(msc313);
+#endif
+
+struct msc313_gpio {
+ void __iomem *base;
+ const struct msc313_gpio_data *gpio_data;
+ u8 *saved;
+};
+
+static void msc313_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
+{
+ struct msc313_gpio *gpio = gpiochip_get_data(chip);
+ u8 gpioreg = readb_relaxed(gpio->base + gpio->gpio_data->offsets[offset]);
+
+ if (value)
+ gpioreg |= MSC313_GPIO_OUT;
+ else
+ gpioreg &= ~MSC313_GPIO_OUT;
+
+ writeb_relaxed(gpioreg, gpio->base + gpio->gpio_data->offsets[offset]);
+}
+
+static int msc313_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+ struct msc313_gpio *gpio = gpiochip_get_data(chip);
+
+ return readb_relaxed(gpio->base + gpio->gpio_data->offsets[offset])
+ & MSC313_GPIO_IN;
+}
+
+static int msc313_gpio_direction_input(struct gpio_chip *chip, unsigned int offset)
+{
+ struct msc313_gpio *gpio = gpiochip_get_data(chip);
+ u8 gpioreg = readb_relaxed(gpio->base + gpio->gpio_data->offsets[offset]);
+
+ gpioreg |= MSC313_GPIO_OEN;
+ writeb_relaxed(gpioreg, gpio->base + gpio->gpio_data->offsets[offset]);
+
+ return 0;
+}
+
+static int msc313_gpio_direction_output(struct gpio_chip *chip, unsigned int offset, int value)
+{
+ struct msc313_gpio *gpio = gpiochip_get_data(chip);
+ u8 gpioreg = readb_relaxed(gpio->base + gpio->gpio_data->offsets[offset]);
+
+ gpioreg &= ~MSC313_GPIO_OEN;
+ if (value)
+ gpioreg |= MSC313_GPIO_OUT;
+ else
+ gpioreg &= ~MSC313_GPIO_OUT;
+ writeb_relaxed(gpioreg, gpio->base + gpio->gpio_data->offsets[offset]);
+
+ return 0;
+}
+
+/*
+ * The interrupt handling happens in the parent interrupt controller,
+ * we don't do anything here.
+ */
+static struct irq_chip msc313_gpio_irqchip = {
+ .name = "GPIO",
+ .irq_eoi = irq_chip_eoi_parent,
+ .irq_mask = irq_chip_mask_parent,
+ .irq_unmask = irq_chip_unmask_parent,
+ .irq_set_type = irq_chip_set_type_parent,
+};
+
+/* The parent interrupt controller needs the GIC interrupt type set to GIC_SPI
+ * so we need to provide the fwspec. Essentially gpiochip_populate_parent_fwspec_twocell
+ * that puts GIC_SPI into the first cell.
+ */
+static void *msc313_gpio_populate_parent_fwspec(struct gpio_chip *gc,
+ unsigned int parent_hwirq,
+ unsigned int parent_type)
+{
+ struct irq_fwspec *fwspec;
+
+ fwspec = kmalloc(sizeof(*fwspec), GFP_KERNEL);
+ if (!fwspec)
+ return NULL;
+
+ fwspec->fwnode = gc->irq.parent_domain->fwnode;
+ fwspec->param_count = 3;
+ fwspec->param[0] = GIC_SPI;
+ fwspec->param[1] = parent_hwirq;
+ fwspec->param[2] = parent_type;
+
+ return fwspec;
+}
+
+static int msc313e_gpio_child_to_parent_hwirq(struct gpio_chip *chip,
+ unsigned int child,
+ unsigned int child_type,
+ unsigned int *parent,
+ unsigned int *parent_type)
+{
+ struct msc313_gpio *priv = gpiochip_get_data(chip);
+ unsigned int offset = priv->gpio_data->offsets[child];
+ int ret = -EINVAL;
+
+ /* only the spi0 pins have interrupts on the parent
+ * on all of the known chips and so far they are all
+ * mapped to the same place
+ */
+ if (offset >= OFF_SPI0_CZ && offset <= OFF_SPI0_DO) {
+ *parent_type = child_type;
+ *parent = ((offset - OFF_SPI0_CZ) >> 2) + 28;
+ ret = 0;
+ }
+
+ return ret;
+}
+
+static int msc313_gpio_probe(struct platform_device *pdev)
+{
+ const struct msc313_gpio_data *match_data;
+ struct msc313_gpio *gpio;
+ struct gpio_chip *gpiochip;
+ struct gpio_irq_chip *gpioirqchip;
+ struct resource *res;
+ struct irq_domain *parent_domain;
+ struct device_node *parent_node;
+ int ret;
+
+ match_data = of_device_get_match_data(&pdev->dev);
+ if (!match_data)
+ return -EINVAL;
+
+ parent_node = of_irq_find_parent(pdev->dev.of_node);
+ if (!parent_node)
+ return -ENODEV;
+
+ parent_domain = irq_find_host(parent_node);
+ if (!parent_domain)
+ return -ENODEV;
+
+ gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
+ if (!gpio)
+ return -ENOMEM;
+
+ gpio->gpio_data = match_data;
+
+ gpio->saved = devm_kzalloc(&pdev->dev, gpio->gpio_data->num * sizeof(*gpio->saved), GFP_KERNEL);
+ if (!gpio->saved)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, gpio);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ gpio->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(gpio->base))
+ return PTR_ERR(gpio->base);
+
+ gpiochip = devm_kzalloc(&pdev->dev, sizeof(*gpiochip), GFP_KERNEL);
+ if (!gpiochip)
+ return -ENOMEM;
+
+ gpiochip->label = DRIVER_NAME;
+ gpiochip->parent = &pdev->dev;
+ gpiochip->request = gpiochip_generic_request;
+ gpiochip->free = gpiochip_generic_free;
+ gpiochip->direction_input = msc313_gpio_direction_input;
+ gpiochip->direction_output = msc313_gpio_direction_output;
+ gpiochip->get = msc313_gpio_get;
+ gpiochip->set = msc313_gpio_set;
+ gpiochip->base = -1;
+ gpiochip->ngpio = gpio->gpio_data->num;
+ gpiochip->names = gpio->gpio_data->names;
+
+ gpioirqchip = &gpiochip->irq;
+ gpioirqchip->chip = &msc313_gpio_irqchip;
+ gpioirqchip->fwnode = of_node_to_fwnode(pdev->dev.of_node);
+ gpioirqchip->parent_domain = parent_domain;
+ gpioirqchip->child_to_parent_hwirq = msc313e_gpio_child_to_parent_hwirq;
+ gpioirqchip->populate_parent_alloc_arg = msc313_gpio_populate_parent_fwspec;
+ gpioirqchip->handler = handle_bad_irq;
+ gpioirqchip->default_type = IRQ_TYPE_NONE;
+
+ ret = gpiochip_add_data(gpiochip, gpio);
+ return ret;
+}
+
+static const struct of_device_id msc313_gpio_of_match[] = {
+#ifdef CONFIG_MACH_INFINITY
+ {
+ .compatible = "mstar,msc313-gpio",
+ .data = &msc313_data,
+ },
+#endif
+ { }
+};
+
+/* The GPIO controller loses the state of the registers when the
+ * SoC goes into suspend to memory mode so we need to save some
+ * of the register bits before suspending and put it back when resuming
+ */
+
+static int __maybe_unused msc313_gpio_suspend(struct device *dev)
+{
+ struct msc313_gpio *gpio = dev_get_drvdata(dev);
+ int i;
+
+ for (i = 0; i < gpio->gpio_data->num; i++)
+ gpio->saved[i] = readb_relaxed(gpio->base + gpio->gpio_data->offsets[i]) & MSC313_GPIO_BITSTOSAVE;
+
+ return 0;
+}
+
+static int __maybe_unused msc313_gpio_resume(struct device *dev)
+{
+ struct msc313_gpio *gpio = dev_get_drvdata(dev);
+ int i;
+
+ for (i = 0; i < gpio->gpio_data->num; i++)
+ writeb_relaxed(gpio->saved[i], gpio->base + gpio->gpio_data->offsets[i]);
+
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(msc313_gpio_ops, msc313_gpio_suspend, msc313_gpio_resume);
+
+static struct platform_driver msc313_gpio_driver = {
+ .driver = {
+ .name = DRIVER_NAME,
+ .of_match_table = msc313_gpio_of_match,
+ .pm = &msc313_gpio_ops,
+ },
+ .probe = msc313_gpio_probe,
+};
+
+builtin_platform_driver(msc313_gpio_driver);
--
2.28.0
On Mon, Oct 19, 2020 at 5:11 PM Daniel Palmer <[email protected]> wrote:
>
> This adds a driver that supports the GPIO block found in
> MStar/SigmaStar ARMv7 SoCs.
>
> The controller seems to support 128 lines but where they
> are wired up differs between chips and no currently known
> chip uses anywhere near 128 lines so there needs to be some
> per-chip data to collect together what lines actually have
> physical pins attached and map the right names to them.
>
> The core peripherals seem to use the same lines on the
> currently known chips but the lines used for the sensor
> interface, lcd controller etc pins seem to be totally
> different between the infinity and mercury chips
>
> The code tries to collect all of the re-usable names,
> offsets etc together so that it's easy to build the extra
> per-chip data for other chips in the future.
>
> So far this only supports the MSC313 and MSC313E chips.
>
> Support for the SSC8336N (mercury5) is trivial to add once
> all of the lines have been mapped out.
...
> +config GPIO_MSC313
> + bool "MStar MSC313 GPIO support"
Why boolean?
> + default y if ARCH_MSTARV7
Simply
default ARCH_MSTARV7
should work as well.
Are you planning to extend this to other boards?
> + depends on ARCH_MSTARV7
> + select GPIOLIB_IRQCHIP
> + help
> + Say Y here to support GPIO on MStar MSC313 and later SoCs.
Please, be more specific. Also it's recommended to have a module name
to be included (but let's understand first why it's not a module)
...
> +/*
> + * Copyright (C) 2020 Daniel Palmer<[email protected]>
> + */
One line.
...
> +#include <linux/of_device.h>
> +#include <linux/of_irq.h>
> +#include <linux/gpio/driver.h>
I believe this should be reworked.
For example, it misses mod_devicetable.h, bits.h, io.h, types.h, etc, but has
...
> +/* These bits need to be saved to correctly restore the
> + * gpio state when resuming from suspend to memory.
> + */
/*
* For this subsystem the comment style for multi-line
* like this.
*/
...
> +#ifdef CONFIG_MACH_INFINITY
Does it make any sense?
> +#endif
...
> + return readb_relaxed(gpio->base + gpio->gpio_data->offsets[offset])
> + & MSC313_GPIO_IN;
Usual pattern is to leave operators on the previous line.
...
> +static struct irq_chip msc313_gpio_irqchip = {
> + .name = "GPIO",
Is this name good enough?
> + .irq_eoi = irq_chip_eoi_parent,
> + .irq_mask = irq_chip_mask_parent,
> + .irq_unmask = irq_chip_unmask_parent,
> + .irq_set_type = irq_chip_set_type_parent,
> +};
...
> +static int msc313e_gpio_child_to_parent_hwirq(struct gpio_chip *chip,
> + unsigned int child,
> + unsigned int child_type,
> + unsigned int *parent,
> + unsigned int *parent_type)
> +{
> + struct msc313_gpio *priv = gpiochip_get_data(chip);
> + unsigned int offset = priv->gpio_data->offsets[child];
> + int ret = -EINVAL;
> +
> + /* only the spi0 pins have interrupts on the parent
> + * on all of the known chips and so far they are all
> + * mapped to the same place
> + */
Comment style!
> + if (offset >= OFF_SPI0_CZ && offset <= OFF_SPI0_DO) {
> + *parent_type = child_type;
> + *parent = ((offset - OFF_SPI0_CZ) >> 2) + 28;
> + ret = 0;
> + }
> +
> + return ret;
Oh, can, for a starter, we use a regular (not-so-twisted) pattern
if (...)
return -EINVAL;
...
return 0;
?
> +}
...
> + gpio->saved = devm_kzalloc(&pdev->dev, gpio->gpio_data->num * sizeof(*gpio->saved), GFP_KERNEL);
devm_kcalloc()
> + if (!gpio->saved)
> + return -ENOMEM;
...
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + gpio->base = devm_ioremap_resource(&pdev->dev, res);
devm_platform_ioremap_resource()
> + if (IS_ERR(gpio->base))
> + return PTR_ERR(gpio->base);
...
> + gpiochip->label = DRIVER_NAME;
Not good. When you use user space how do you distinguish if more than
one chip appears in the system?
...
> + ret = gpiochip_add_data(gpiochip, gpio);
> + return ret;
return ...(...);
Why not devm_gpiochip_add_data() ?
...
> +static const struct of_device_id msc313_gpio_of_match[] = {
> +#ifdef CONFIG_MACH_INFINITY
To me this makes no sense.
> + {
> + .compatible = "mstar,msc313-gpio",
> + .data = &msc313_data,
> + },
> +#endif
> + { }
> +};
...
> +/* The GPIO controller loses the state of the registers when the
> + * SoC goes into suspend to memory mode so we need to save some
> + * of the register bits before suspending and put it back when resuming
> + */
Comment style!
> +
Redundant blank line.
...
> +static int __maybe_unused msc313_gpio_resume(struct device *dev)
> +{
> +}
> +
Redundant blank line.
> +static SIMPLE_DEV_PM_OPS(msc313_gpio_ops, msc313_gpio_suspend, msc313_gpio_resume);
...
> +static struct platform_driver msc313_gpio_driver = {
> + .driver = {
> + .name = DRIVER_NAME,
> + .of_match_table = msc313_gpio_of_match,
> + .pm = &msc313_gpio_ops,
You still allow to unbind.
> + },
> + .probe = msc313_gpio_probe,
> +};
> +
Redundant blank line.
> +builtin_platform_driver(msc313_gpio_driver);
Why?
--
With Best Regards,
Andy Shevchenko
Hi Andy,
On Tue, 20 Oct 2020 at 20:59, Andy Shevchenko <[email protected]> wrote:
> > +config GPIO_MSC313
> > + bool "MStar MSC313 GPIO support"
>
> Why boolean?
Because it's a built in driver. I could change it to tristate/a module
but I didn't think it needed to be one.
The machines this is used on generally only have 64 or 128MB of RAM so
the kernel is usually built without modules and only the totally
required stuff built in.
> > + default y if ARCH_MSTARV7
>
> Simply
> default ARCH_MSTARV7
> should work as well.
>
> Are you planning to extend this to other boards?
I think I copy/pasted the block above there. I'll fix this up.
As for other boards. I think this GPIO controller is only present in
MStar's SoCs and some MediaTek SoCs that inherited parts from MStar
after MediaTek bought them. Like the MStar interrupt controller is
present in some MediaTek TV chips.
>
> > + depends on ARCH_MSTARV7
> > + select GPIOLIB_IRQCHIP
> > + help
> > + Say Y here to support GPIO on MStar MSC313 and later SoCs.
>
> Please, be more specific. Also it's recommended to have a module name
> to be included (but let's understand first why it's not a module)
Ok. I'll rework that. As for it not being a module. I can make it
possible to build it
as a module. I just didn't really think it needed to be one.
> > +#include <linux/of_device.h>
> > +#include <linux/of_irq.h>
> > +#include <linux/gpio/driver.h>
>
> I believe this should be reworked.
> For example, it misses mod_devicetable.h, bits.h, io.h, types.h, etc, but has
I'll look at this again.
> > +/* These bits need to be saved to correctly restore the
> > + * gpio state when resuming from suspend to memory.
> > + */
>
> /*
> * For this subsystem the comment style for multi-line
> * like this.
> */
Sorry, I'll fix these up.
> > +#ifdef CONFIG_MACH_INFINITY
>
> Does it make any sense?
>
> > +#endif
It doesn't make a lot of sense right now but it makes a bit more sense
when the support for the mercury chips is added. They have their own
set of offsets
for the used pins. I cut that out of this series because I haven't
fully reverse engineered all of the pins for those chips yet so the
support for them has a lot of guesses and notes in the code.
Anyhow, with only 64MB of RAM I thought it made sense to not compile
in the mercury tables when support for those machines isn't enabled.
I'll drop the if/defs for the next version.
> > +static struct irq_chip msc313_gpio_irqchip = {
> > + .name = "GPIO",
>
> Is this name good enough?
>
There is only one GPIO block in the chips this is for so I think it's
unique at least.
> > + gpiochip->label = DRIVER_NAME;
>
> Not good. When you use user space how do you distinguish if more than
> one chip appears in the system?
So far there is only ever one of these GPIO controller for the whole system.
There is another GPIO block in the system but it uses another driver
as the register layout is totally different.
Thank you for all of the comments. Sorry about the multiple style issues.
I thought checkpatch had my back on that.
Thanks,
Daniel
On Tue, Oct 20, 2020 at 1:59 PM Andy Shevchenko
<[email protected]> wrote:
> On Mon, Oct 19, 2020 at 5:11 PM Daniel Palmer <[email protected]> wrote:
> > +config GPIO_MSC313
> > + bool "MStar MSC313 GPIO support"
> > + default y if ARCH_MSTARV7
I think it is possible to write:
default ARCH_MSTARV7
For this.
> Why boolean?
I answered this question in some other mail but there is usually somewhat
a good reason for this but let's discuss it a bit.
The following usecase:
- You have a generic distribution such as Android
- The generic distribution does not use initramfs to support basic
drivers (does Android? Nowadays?)
- So all modules would need to load from actual storage media.
- The storage media is an SD card.
- The SD card reader has a card detect line connected to one
of the GPIO lines.
- Now we have catch-22 because there is no way to load the
GPIO driver modules from the storage media because the
driver is needed to mount the storage media.
I do not know if this "never happens" because every generic
distribution "should" be using initramfs for their drivers. But it
provides a convenient way for users to shoot themselves in the
foot and be frustrated about that their root filesystem is not
mounting.
I do not think this is limited to GPIO card detects but it is a very
immediate example.
What is the consensus here?
Yours,
Linus Walleij
On Mon, Oct 19, 2020 at 4:10 PM Daniel Palmer <[email protected]> wrote:
> This adds a driver that supports the GPIO block found in
> MStar/SigmaStar ARMv7 SoCs.
>
> The controller seems to support 128 lines but where they
> are wired up differs between chips and no currently known
> chip uses anywhere near 128 lines so there needs to be some
> per-chip data to collect together what lines actually have
> physical pins attached and map the right names to them.
>
> The core peripherals seem to use the same lines on the
> currently known chips but the lines used for the sensor
> interface, lcd controller etc pins seem to be totally
> different between the infinity and mercury chips
>
> The code tries to collect all of the re-usable names,
> offsets etc together so that it's easy to build the extra
> per-chip data for other chips in the future.
>
> So far this only supports the MSC313 and MSC313E chips.
>
> Support for the SSC8336N (mercury5) is trivial to add once
> all of the lines have been mapped out.
>
> Signed-off-by: Daniel Palmer <[email protected]>
This looks really nice, the generic hierarchical IRQchip does
its job very well here.
I saw you would send another version but this already looks
like merge material.
Certainly any remaining issues can be ironed out in-tree.
> +config GPIO_MSC313
> + bool "MStar MSC313 GPIO support"
> + default y if ARCH_MSTARV7
> + depends on ARCH_MSTARV7
> + select GPIOLIB_IRQCHIP
select IRQ_DOMAIN_HIERARCHY
since you are dependent on this.
(Else people will soon report problems with randconfig...)
> +/* The parent interrupt controller needs the GIC interrupt type set to GIC_SPI
> + * so we need to provide the fwspec. Essentially gpiochip_populate_parent_fwspec_twocell
> + * that puts GIC_SPI into the first cell.
> + */
> +static void *msc313_gpio_populate_parent_fwspec(struct gpio_chip *gc,
> + unsigned int parent_hwirq,
> + unsigned int parent_type)
> +{
> + struct irq_fwspec *fwspec;
> +
> + fwspec = kmalloc(sizeof(*fwspec), GFP_KERNEL);
> + if (!fwspec)
> + return NULL;
> +
> + fwspec->fwnode = gc->irq.parent_domain->fwnode;
> + fwspec->param_count = 3;
> + fwspec->param[0] = GIC_SPI;
> + fwspec->param[1] = parent_hwirq;
> + fwspec->param[2] = parent_type;
> +
> + return fwspec;
> +}
Clever. Looping in Marc Z so he can say if this looks allright to him.
> +static int msc313e_gpio_child_to_parent_hwirq(struct gpio_chip *chip,
> + unsigned int child,
> + unsigned int child_type,
> + unsigned int *parent,
> + unsigned int *parent_type)
> +{
> + struct msc313_gpio *priv = gpiochip_get_data(chip);
> + unsigned int offset = priv->gpio_data->offsets[child];
> + int ret = -EINVAL;
> +
> + /* only the spi0 pins have interrupts on the parent
> + * on all of the known chips and so far they are all
> + * mapped to the same place
> + */
> + if (offset >= OFF_SPI0_CZ && offset <= OFF_SPI0_DO) {
> + *parent_type = child_type;
> + *parent = ((offset - OFF_SPI0_CZ) >> 2) + 28;
> + ret = 0;
> + }
> +
> + return ret;
> +}
Neat!
> +static int msc313_gpio_probe(struct platform_device *pdev)
> +{
> + const struct msc313_gpio_data *match_data;
> + struct msc313_gpio *gpio;
> + struct gpio_chip *gpiochip;
> + struct gpio_irq_chip *gpioirqchip;
> + struct resource *res;
> + struct irq_domain *parent_domain;
> + struct device_node *parent_node;
> + int ret;
> +
> + match_data = of_device_get_match_data(&pdev->dev);
There is a lot of referencing &pdev->dev.
I would add a local variable like this:
struct device *dev = &pdev->dev
and replace all &pdev->dev with that. It will make the code more
compact and easier to read.
Yours,
Linus Walleij
On 2020-11-05 09:40, Linus Walleij wrote:
> On Mon, Oct 19, 2020 at 4:10 PM Daniel Palmer <[email protected]> wrote:
[...]
>> +/* The parent interrupt controller needs the GIC interrupt type set
>> to GIC_SPI
>> + * so we need to provide the fwspec. Essentially
>> gpiochip_populate_parent_fwspec_twocell
>> + * that puts GIC_SPI into the first cell.
>> + */
nit: comment style.
>> +static void *msc313_gpio_populate_parent_fwspec(struct gpio_chip *gc,
>> + unsigned int
>> parent_hwirq,
>> + unsigned int parent_type)
>> +{
>> + struct irq_fwspec *fwspec;
>> +
>> + fwspec = kmalloc(sizeof(*fwspec), GFP_KERNEL);
>> + if (!fwspec)
>> + return NULL;
>> +
>> + fwspec->fwnode = gc->irq.parent_domain->fwnode;
>> + fwspec->param_count = 3;
>> + fwspec->param[0] = GIC_SPI;
>> + fwspec->param[1] = parent_hwirq;
>> + fwspec->param[2] = parent_type;
>> +
>> + return fwspec;
>> +}
>
> Clever. Looping in Marc Z so he can say if this looks allright to him.
Yup, this looks correct. However, looking at the bit of the patch that
isn't quoted here, I see that msc313_gpio_irqchip doesn't have a
.irq_set_affinity callback. Is this system UP only?
Thanks,
M.
--
Jazz is not dead. It just smells funny...
Hi Marc,
On Thu, 5 Nov 2020 at 21:08, Marc Zyngier <[email protected]> wrote:
>
> On 2020-11-05 09:40, Linus Walleij wrote:
> > On Mon, Oct 19, 2020 at 4:10 PM Daniel Palmer <[email protected]> wrote:
>
> [...]
>
> >> +/* The parent interrupt controller needs the GIC interrupt type set
> >> to GIC_SPI
> >> + * so we need to provide the fwspec. Essentially
> >> gpiochip_populate_parent_fwspec_twocell
> >> + * that puts GIC_SPI into the first cell.
> >> + */
>
> nit: comment style.
I've fixed these and some other bits for the v3.
I've held off on pushing that until the rest of it seemed right.
> >> +static void *msc313_gpio_populate_parent_fwspec(struct gpio_chip *gc,
> >> + unsigned int
> >> parent_hwirq,
> >> + unsigned int parent_type)
> >> +{
> >> + struct irq_fwspec *fwspec;
> >> +
> >> + fwspec = kmalloc(sizeof(*fwspec), GFP_KERNEL);
> >> + if (!fwspec)
> >> + return NULL;
> >> +
> >> + fwspec->fwnode = gc->irq.parent_domain->fwnode;
> >> + fwspec->param_count = 3;
> >> + fwspec->param[0] = GIC_SPI;
> >> + fwspec->param[1] = parent_hwirq;
> >> + fwspec->param[2] = parent_type;
> >> +
> >> + return fwspec;
> >> +}
> >
> > Clever. Looping in Marc Z so he can say if this looks allright to him.
>
> Yup, this looks correct. However, looking at the bit of the patch that
> isn't quoted here, I see that msc313_gpio_irqchip doesn't have a
> .irq_set_affinity callback. Is this system UP only?
What is in mainline right now is UP only but there are chips with a
second cortex A7 that I have working in my tree.
So I will add that in for v3 if I can work out what I should actually
do there. :)
Thanks,
Daniel
On 2020-11-05 15:23, Daniel Palmer wrote:
> Hi Marc,
>
> On Thu, 5 Nov 2020 at 21:08, Marc Zyngier <[email protected]> wrote:
>>
>> On 2020-11-05 09:40, Linus Walleij wrote:
>> > On Mon, Oct 19, 2020 at 4:10 PM Daniel Palmer <[email protected]> wrote:
>>
>> [...]
>>
>> >> +/* The parent interrupt controller needs the GIC interrupt type set
>> >> to GIC_SPI
>> >> + * so we need to provide the fwspec. Essentially
>> >> gpiochip_populate_parent_fwspec_twocell
>> >> + * that puts GIC_SPI into the first cell.
>> >> + */
>>
>> nit: comment style.
>
> I've fixed these and some other bits for the v3.
> I've held off on pushing that until the rest of it seemed right.
>
>> >> +static void *msc313_gpio_populate_parent_fwspec(struct gpio_chip *gc,
>> >> + unsigned int
>> >> parent_hwirq,
>> >> + unsigned int parent_type)
>> >> +{
>> >> + struct irq_fwspec *fwspec;
>> >> +
>> >> + fwspec = kmalloc(sizeof(*fwspec), GFP_KERNEL);
>> >> + if (!fwspec)
>> >> + return NULL;
>> >> +
>> >> + fwspec->fwnode = gc->irq.parent_domain->fwnode;
>> >> + fwspec->param_count = 3;
>> >> + fwspec->param[0] = GIC_SPI;
>> >> + fwspec->param[1] = parent_hwirq;
>> >> + fwspec->param[2] = parent_type;
>> >> +
>> >> + return fwspec;
>> >> +}
>> >
>> > Clever. Looping in Marc Z so he can say if this looks allright to him.
>>
>> Yup, this looks correct. However, looking at the bit of the patch that
>> isn't quoted here, I see that msc313_gpio_irqchip doesn't have a
>> .irq_set_affinity callback. Is this system UP only?
>
> What is in mainline right now is UP only but there are chips with a
> second cortex A7 that I have working in my tree.
> So I will add that in for v3 if I can work out what I should actually
> do there. :)
Probably nothing more than setting the callback to
irq_chip_set_affinity_parent,
I'd expect.
M.
--
Jazz is not dead. It just smells funny...
On Thu, Nov 5, 2020 at 4:43 PM Marc Zyngier <[email protected]> wrote:
> On 2020-11-05 15:23, Daniel Palmer wrote:
> > On Thu, 5 Nov 2020 at 21:08, Marc Zyngier <[email protected]> wrote:
> > > I see that msc313_gpio_irqchip doesn't have a
> >> .irq_set_affinity callback. Is this system UP only?
> >
> > What is in mainline right now is UP only but there are chips with a
> > second cortex A7 that I have working in my tree.
> > So I will add that in for v3 if I can work out what I should actually
> > do there. :)
>
> Probably nothing more than setting the callback to
> irq_chip_set_affinity_parent,
Hm, is this something all GPIO irqchips used on SMP systems
should be doing? Or just hierarchical ones?
Yours,
Linus Walleij
On 2020-11-10 14:02, Linus Walleij wrote:
> On Thu, Nov 5, 2020 at 4:43 PM Marc Zyngier <[email protected]> wrote:
>> On 2020-11-05 15:23, Daniel Palmer wrote:
>> > On Thu, 5 Nov 2020 at 21:08, Marc Zyngier <[email protected]> wrote:
>
>> > > I see that msc313_gpio_irqchip doesn't have a
>> >> .irq_set_affinity callback. Is this system UP only?
>> >
>> > What is in mainline right now is UP only but there are chips with a
>> > second cortex A7 that I have working in my tree.
>> > So I will add that in for v3 if I can work out what I should actually
>> > do there. :)
>>
>> Probably nothing more than setting the callback to
>> irq_chip_set_affinity_parent,
>
> Hm, is this something all GPIO irqchips used on SMP systems
> should be doing? Or just hierarchical ones?
Probably only the hierarchical ones. I'd expect the non-hierarchical
GPIOs to be muxed behind a single interrupt, which makes it impossible
to move a single GPIO around, and moving the mux interrupt would break
userspace's expectations that interrupts move independently of each
others.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
On Tue, Nov 10, 2020 at 3:19 PM Marc Zyngier <[email protected]> wrote:
> On 2020-11-10 14:02, Linus Walleij wrote:
> >> Probably nothing more than setting the callback to
> >> irq_chip_set_affinity_parent,
> >
> > Hm, is this something all GPIO irqchips used on SMP systems
> > should be doing? Or just hierarchical ones?
>
> Probably only the hierarchical ones. I'd expect the non-hierarchical
> GPIOs to be muxed behind a single interrupt, which makes it impossible
> to move a single GPIO around, and moving the mux interrupt would break
> userspace's expectations that interrupts move independently of each
> others.
I found two suspects and sent patches. I think I might have some
more candidates down in pinctrl. I do have some hierarchical IRQ
that is on UP systems, I suppose these are not affected.
Yours,
Linus Walleij
On 2020-11-11 14:09, Linus Walleij wrote:
> On Tue, Nov 10, 2020 at 3:19 PM Marc Zyngier <[email protected]> wrote:
>> On 2020-11-10 14:02, Linus Walleij wrote:
>
>> >> Probably nothing more than setting the callback to
>> >> irq_chip_set_affinity_parent,
>> >
>> > Hm, is this something all GPIO irqchips used on SMP systems
>> > should be doing? Or just hierarchical ones?
>>
>> Probably only the hierarchical ones. I'd expect the non-hierarchical
>> GPIOs to be muxed behind a single interrupt, which makes it impossible
>> to move a single GPIO around, and moving the mux interrupt would break
>> userspace's expectations that interrupts move independently of each
>> others.
>
> I found two suspects and sent patches. I think I might have some
> more candidates down in pinctrl. I do have some hierarchical IRQ
> that is on UP systems, I suppose these are not affected.
Yup, they look good. Feel free to add my Ack to them.
And yes, UP systems are naturally oblivious of interrupt affinity.
Thanks,
M.
--
Jazz is not dead. It just smells funny...