gpio: mmio: add get_set inverted direction io support
cover gpio: mmio: add get_set inverted direction io support
When bgpio direction register use dirin and setting BGPIOF_READ_OUTPUT_REG_SET flag, the get_set I/O functions reading the inverted set register of each direction, it means:
when direction=in the get_set function read set register. when direction=out the get_set function read dat register.
but is should be inverted.
conversion about it with Linus Walleij:
https://www.spinics.net/lists/devicetree/msg241973.html
to solve it, adding get_set_inv_dir and get_set_multiple_inv_dir I/O functions to call the data register when the direction is input and set register when the direction is output.
the functions will linked to the I/O get functions if the user set BGPIOF_INVERTED_REG_DIR flag in the bgpio initialization.
Tomer Maimon (1):
gpio: mmio: add inverted direction get_set io support
drivers/gpio/gpio-mmio.c | 48 ++++++++++++++++++++++++++++++++++++++++++--- include/linux/gpio/driver.h | 1 + 2 files changed, 46 insertions(+), 3 deletions(-)
Signature · 1 line
2.14.1
PATCH 1/1 gpio: mmio: add inverted direction get_set io support
Add get_set_inv_dir and get_set_multiple_inv_dir I/O functions to call the data register when the dirction is input and set register when the direction is output.
the functions will linked to the I/O get functions if the user set BGPIOF_INVERTED_REG_DIR flag in the bgpio initialization.
--- drivers/gpio/gpio-mmio.c | 48 ++++++++++++++++++++++++++++++++++++++++++--- include/linux/gpio/driver.h | 1 + 2 files changed, 46 insertions(+), 3 deletions(-)
drivers/gpio/gpio-mmio.c +45 -3
@@ -168,6 +168,40 @@ static int bgpio_get_set_multiple(struct gpio_chip *gc, unsigned long *mask,return 0 ; } +/* get set function when the direction is inverted */ +static int bgpio_get_set_inv_dir (struct gpio_chip *gc,unsigned int gpio) +{ +unsigned long pinmask =bgpio_line2mask (gc, gpio); + +if (gc->bgpio_dir & pinmask) +return !!(gc->read_reg (gc->reg_dat) & pinmask); +else +return !!(gc->read_reg (gc->reg_set) & pinmask); +} + +/* get set multiple function when the direction is inverted */ +static int bgpio_get_set_multiple_inv_dir (struct gpio_chip *gc, +unsigned long *mask, +unsigned long *bits) +{ +unsigned long get_mask =0 ; +unsigned long set_mask =0 ; + +/* Make sure we first clear any bits that are zero when we read the register */ + *bits &= ~*mask; + +/* Exploit the fact that we know which directions are set */ + set_mask = *mask & ~gc->bgpio_dir; + get_mask = *mask & gc->bgpio_dir; + +if (set_mask) + *bits |= gc->read_reg (gc->reg_set) & set_mask; +if (get_mask) + *bits |= gc->read_reg (gc->reg_dat) & get_mask; + +return 0 ; +} +static int bgpio_get (struct gpio_chip *gc,unsigned int gpio) {return !!(gc->read_reg (gc->reg_dat) &bgpio_line2mask (gc, gpio));
@@ -525,9 +559,17 @@ static int bgpio_setup_io(struct gpio_chip *gc,if (!(flags &BGPIOF_UNREADABLE_REG_SET ) && (flags &BGPIOF_READ_OUTPUT_REG_SET )) { - gc->get = bgpio_get_set; -if (!gc->be_bits) - gc->get_multiple = bgpio_get_set_multiple; +/* if the direction inverted */ +if (flags &BGPIOF_INVERTED_REG_DIR ) { + gc->get = bgpio_get_set_inv_dir; +if (!gc->be_bits) + gc->get_multiple = + bgpio_get_set_multiple_inv_dir; + }else { + gc->get = bgpio_get_set; +if (!gc->be_bits) + gc->get_multiple = bgpio_get_set_multiple; + }/* * We deliberately avoid assigning the ->get_multiple() call * for big endian mirrored registers which are ALSO reflecting
include/linux/gpio/driver.h +1 -0
@@ -425,6 +425,7 @@ int bgpio_init(struct gpio_chip *gc, struct device *dev,#define BGPIOF_BIG_ENDIAN_BYTE_ORDER BIT(3)#define BGPIOF_READ_OUTPUT_REG_SET BIT(4)/* reg_set stores output value */ #define BGPIOF_NO_OUTPUT BIT(5)/* only input */ +#define BGPIOF_INVERTED_REG_DIR BIT(6)/* reg_dir inverted */ #endif
Signature · 1 line
2.14.1
Re: [PATCH v1 1/1] gpio: mmio: add inverted direction get_set io support
drivers/gpio/gpio-mmio.c static int bgpio_get_set_multiple(struct gpio_chip *gc, unsigned long *mask, · line 191
Quoted 8 lines · Tomer Maimon
Add
get_set_inv_dirandget_set_multiple_inv_dirI/O functions to call the data register when the dirction is input and set register when the direction is output.
the functions will linked to the I/O get functions if the user setBGPIOF_INVERTED_REG_DIRflag in the bgpio initialization.drivers/gpio/gpio-mmio.c +2
-0+/* Make sure we first clear any bits that are zero when we read the register */ + *bits &= ~*mask;
Theoretically it's possible to get mask and bits longer than one long, and bitmap API has to be used.
Though, it seems entire driver has been written in an assumption that it's never happen.
drivers/gpio/gpio-mmio.c static int bgpio_setup_io(struct gpio_chip *gc, · line 567
Quoted 2 lines
drivers/gpio/gpio-mmio.c +2
-0+ gc->get_multiple = + bgpio_get_set_multiple_inv_dir;
I think you may keep it on one line.
Signature · 2 lines
With Best Regards, Andy Shevchenko
Re: [PATCH v1 1/1] gpio: mmio: add inverted direction get_set io support
In reply to Tomer MaimonQuoted 7 lines · Tomer Maimon
Add
get_set_inv_dirandget_set_multiple_inv_dirI/O functions to call the data register when the dirction is input and set register when the direction is output.
the functions will linked to the I/O get functions if the user setBGPIOF_INVERTED_REG_DIRflag in the bgpio initialization.Signed-off-by Tomer Maimon <[email protected]>
I think you uncovered a bug. This is however not the best fix IMO.
Sorry for not understanding the issue at first, I am sometimes pretty slow in the head. :(
I'm sending a patch that I hope fixes the real problem in an elegant way, and makes it possible to just define dirin and BGPIOF_READ_OUTPUT_REG_SET.
Yours,
Linus Walleij