Skip to content

Commit

Permalink
Blackfin: gpio: add peripheral group check
Browse files Browse the repository at this point in the history 
Many Blackfin parts group sets of pins into a single functional unit.
This means you cannot use different pins within a group for different
peripherals.  Our resource conflict checking thus far has been limited
to individual pins, so if someone tried to grab a different pin from
the same group, it would be allowed while silently changing the other
pins in the same group.

One common example is the pin set PG12 - PG15 on BF51x parts.  They
may either be used with SPI0 (1st function), or they may be used with
PTP/PWM/AMS3 (3rd function).  Ideally, we'd like to use PG12 - PG14
for SPI0 while using PG15 with AMS3, but the hardware does not permit
this.  In the past, the software would allow the pins to be requested
this way, but ultimately things like the Blackfin SPI driver would
stop working when the hardware rerouted to a different peripheral.

Signed-off-by: steven miao <realmz6@gmail.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
  • Loading branch information
steven miao authored and Mike Frysinger committed Oct 22, 2010
1 parent a71159b commit 05bbec3
Showing 1 changed file with 118 additions and 67 deletions.
185 changes: 118 additions & 67 deletions arch/blackfin/kernel/bfin_gpio.c
View file
Original file line number Diff line number Diff line change
@@ -1,7 +1,7 @@
/*
* GPIO Abstraction Layer
*
* Copyright 2006-2009 Analog Devices Inc.
* Copyright 2006-2010 Analog Devices Inc.
*
* Licensed under the GPL-2 or later
*/
Expand Down Expand Up @@ -215,82 +215,91 @@ static void port_setup(unsigned gpio, unsigned short usage)
}

#ifdef BF537_FAMILY
static struct {
unsigned short res;
unsigned short offset;
} port_mux_lut[] = {
{.res = P_PPI0_D13, .offset = 11},
{.res = P_PPI0_D14, .offset = 11},
{.res = P_PPI0_D15, .offset = 11},
{.res = P_SPORT1_TFS, .offset = 11},
{.res = P_SPORT1_TSCLK, .offset = 11},
{.res = P_SPORT1_DTPRI, .offset = 11},
{.res = P_PPI0_D10, .offset = 10},
{.res = P_PPI0_D11, .offset = 10},
{.res = P_PPI0_D12, .offset = 10},
{.res = P_SPORT1_RSCLK, .offset = 10},
{.res = P_SPORT1_RFS, .offset = 10},
{.res = P_SPORT1_DRPRI, .offset = 10},
{.res = P_PPI0_D8, .offset = 9},
{.res = P_PPI0_D9, .offset = 9},
{.res = P_SPORT1_DRSEC, .offset = 9},
{.res = P_SPORT1_DTSEC, .offset = 9},
{.res = P_TMR2, .offset = 8},
{.res = P_PPI0_FS3, .offset = 8},
{.res = P_TMR3, .offset = 7},
{.res = P_SPI0_SSEL4, .offset = 7},
{.res = P_TMR4, .offset = 6},
{.res = P_SPI0_SSEL5, .offset = 6},
{.res = P_TMR5, .offset = 5},
{.res = P_SPI0_SSEL6, .offset = 5},
{.res = P_UART1_RX, .offset = 4},
{.res = P_UART1_TX, .offset = 4},
{.res = P_TMR6, .offset = 4},
{.res = P_TMR7, .offset = 4},
{.res = P_UART0_RX, .offset = 3},
{.res = P_UART0_TX, .offset = 3},
{.res = P_DMAR0, .offset = 3},
{.res = P_DMAR1, .offset = 3},
{.res = P_SPORT0_DTSEC, .offset = 1},
{.res = P_SPORT0_DRSEC, .offset = 1},
{.res = P_CAN0_RX, .offset = 1},
{.res = P_CAN0_TX, .offset = 1},
{.res = P_SPI0_SSEL7, .offset = 1},
{.res = P_SPORT0_TFS, .offset = 0},
{.res = P_SPORT0_DTPRI, .offset = 0},
{.res = P_SPI0_SSEL2, .offset = 0},
{.res = P_SPI0_SSEL3, .offset = 0},
static const s8 port_mux[] = {
[GPIO_PF0] = 3,
[GPIO_PF1] = 3,
[GPIO_PF2] = 4,
[GPIO_PF3] = 4,
[GPIO_PF4] = 5,
[GPIO_PF5] = 6,
[GPIO_PF6] = 7,
[GPIO_PF7] = 8,
[GPIO_PF8 ... GPIO_PF15] = -1,
[GPIO_PG0 ... GPIO_PG7] = -1,
[GPIO_PG8] = 9,
[GPIO_PG9] = 9,
[GPIO_PG10] = 10,
[GPIO_PG11] = 10,
[GPIO_PG12] = 10,
[GPIO_PG13] = 11,
[GPIO_PG14] = 11,
[GPIO_PG15] = 11,
[GPIO_PH0 ... GPIO_PH15] = -1,
[PORT_PJ0 ... PORT_PJ3] = -1,
[PORT_PJ4] = 1,
[PORT_PJ5] = 1,
[PORT_PJ6 ... PORT_PJ9] = -1,
[PORT_PJ10] = 0,
[PORT_PJ11] = 0,
};

static void portmux_setup(unsigned short per)
static int portmux_group_check(unsigned short per)
{
u16 y, offset, muxreg;
u16 ident = P_IDENT(per);
u16 function = P_FUNCT2MUX(per);
s8 offset = port_mux[ident];
u16 m, pmux, pfunc;

for (y = 0; y < ARRAY_SIZE(port_mux_lut); y++) {
if (port_mux_lut[y].res == per) {

/* SET PORTMUX REG */

offset = port_mux_lut[y].offset;
muxreg = bfin_read_PORT_MUX();
if (offset < 0)
return 0;

if (offset != 1)
muxreg &= ~(1 << offset);
else
muxreg &= ~(3 << 1);
pmux = bfin_read_PORT_MUX();
for (m = 0; m < ARRAY_SIZE(port_mux); ++m) {
if (m == ident)
continue;
if (port_mux[m] != offset)
continue;
if (!is_reserved(peri, m, 1))
continue;

muxreg |= (function << offset);
bfin_write_PORT_MUX(muxreg);
if (offset == 1)
pfunc = (pmux >> offset) & 3;
else
pfunc = (pmux >> offset) & 1;
if (pfunc != function) {
pr_err("pin group conflict! request pin %d func %d conflict with pin %d func %d\n",
ident, function, m, pfunc);
return -EINVAL;
}
}

return 0;
}

static void portmux_setup(unsigned short per)
{
u16 ident = P_IDENT(per);
u16 function = P_FUNCT2MUX(per);
s8 offset = port_mux[ident];
u16 pmux;

if (offset == -1)
return;

pmux = bfin_read_PORT_MUX();
if (offset != 1)
pmux &= ~(1 << offset);
else
pmux &= ~(3 << 1);
pmux |= (function << offset);
bfin_write_PORT_MUX(pmux);
}
#elif defined(CONFIG_BF54x)
inline void portmux_setup(unsigned short per)
{
u32 pmux;
u16 ident = P_IDENT(per);
u16 function = P_FUNCT2MUX(per);
u32 pmux;

pmux = gpio_array[gpio_bank(ident)]->port_mux;

Expand All @@ -302,27 +311,65 @@ inline void portmux_setup(unsigned short per)

inline u16 get_portmux(unsigned short per)
{
u32 pmux;
u16 ident = P_IDENT(per);

pmux = gpio_array[gpio_bank(ident)]->port_mux;

u32 pmux = gpio_array[gpio_bank(ident)]->port_mux;
return (pmux >> (2 * gpio_sub_n(ident)) & 0x3);
}
static int portmux_group_check(unsigned short per)
{
return 0;
}
#elif defined(CONFIG_BF52x) || defined(CONFIG_BF51x)
static int portmux_group_check(unsigned short per)
{
u16 ident = P_IDENT(per);
u16 function = P_FUNCT2MUX(per);
u8 offset = pmux_offset[gpio_bank(ident)][gpio_sub_n(ident)];
u16 pin, gpiopin, pfunc;

for (pin = 0; pin < GPIO_BANKSIZE; ++pin) {
if (offset != pmux_offset[gpio_bank(ident)][pin])
continue;

gpiopin = gpio_bank(ident) * GPIO_BANKSIZE + pin;
if (gpiopin == ident)
continue;
if (!is_reserved(peri, gpiopin, 1))
continue;

pfunc = *port_mux[gpio_bank(ident)];
pfunc = (pfunc >> offset) & 3;
if (pfunc != function) {
pr_err("pin group conflict! request pin %d func %d conflict with pin %d func %d\n",
ident, function, gpiopin, pfunc);
return -EINVAL;
}
}

return 0;
}

inline void portmux_setup(unsigned short per)
{
u16 pmux, ident = P_IDENT(per), function = P_FUNCT2MUX(per);
u16 ident = P_IDENT(per);
u16 function = P_FUNCT2MUX(per);
u8 offset = pmux_offset[gpio_bank(ident)][gpio_sub_n(ident)];
u16 pmux;

pmux = *port_mux[gpio_bank(ident)];
if (((pmux >> offset) & 3) == function)
return;
pmux &= ~(3 << offset);
pmux |= (function & 3) << offset;
*port_mux[gpio_bank(ident)] = pmux;
SSYNC();
}
#else
# define portmux_setup(...) do { } while (0)
static int portmux_group_check(unsigned short per)
{
return 0;
}
#endif

#ifndef CONFIG_BF54x
Expand Down Expand Up @@ -735,6 +782,10 @@ int peripheral_request(unsigned short per, const char *label)
}
}

if (unlikely(portmux_group_check(per))) {
hard_local_irq_restore(flags);
return -EBUSY;
}
anyway:
reserve(peri, ident);

Expand Down

0 comments on commit 05bbec3

Please sign in to comment.