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authorLinus Walleij <linus.walleij@linaro.org>2019-06-01 00:37:56 +0200
committerWolfram Sang <wsa@the-dreams.de>2019-06-12 13:20:23 +0200
commitfdb7e884ad617f8aa69abdd7f39e3fdac85e081e (patch)
tree8040de47cccdb9797aa15272df7d0afde3431307 /arch/arm
parented7357c9f9b6a560992446c37260be25e514c4ab (diff)
downloadlinux-fdb7e884ad617f8aa69abdd7f39e3fdac85e081e.tar.bz2
i2c: iop: Use GPIO descriptors
The IOP3xx has some elaborate code to directly slam the GPIO lines multiplexed with I2C down low before enablement, apparently a workaround for a hardware bug found in the early chips. After consulting the developer documentation for IOP80321 and IOP80331 I can clearly see that this may be useful for IOP80321 family (mach-iop32x) but it is highly dubious for any 80331 series or later chip: in these chips the lines are not multiplexed for UARTs. We convert the code to pass optional GPIO descriptors and register these only on the 80321-based boards where it makes sense, optionally obtain them in the driver and use the gpiod_set_raw_value() to ascertain the line gets driven low when needed. The GPIO driver does not give the GPIO chip a reasonable label so the patch also adds that so that these machine descriptor tables can be used. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/include/asm/hardware/iop3xx.h2
-rw-r--r--arch/arm/mach-iop32x/em7210.c3
-rw-r--r--arch/arm/mach-iop32x/glantank.c3
-rw-r--r--arch/arm/mach-iop32x/iq31244.c3
-rw-r--r--arch/arm/mach-iop32x/iq80321.c3
-rw-r--r--arch/arm/mach-iop32x/n2100.c2
-rw-r--r--arch/arm/plat-iop/i2c.c24
7 files changed, 40 insertions, 0 deletions
diff --git a/arch/arm/include/asm/hardware/iop3xx.h b/arch/arm/include/asm/hardware/iop3xx.h
index 2594a95ff19a..a15d08160e8f 100644
--- a/arch/arm/include/asm/hardware/iop3xx.h
+++ b/arch/arm/include/asm/hardware/iop3xx.h
@@ -305,6 +305,8 @@ extern struct platform_device iop3xx_dma_1_channel;
extern struct platform_device iop3xx_aau_channel;
extern struct platform_device iop3xx_i2c0_device;
extern struct platform_device iop3xx_i2c1_device;
+extern struct gpiod_lookup_table iop3xx_i2c0_gpio_lookup;
+extern struct gpiod_lookup_table iop3xx_i2c1_gpio_lookup;
#endif
diff --git a/arch/arm/mach-iop32x/em7210.c b/arch/arm/mach-iop32x/em7210.c
index 77e1ff057303..d2bcbac6b7f2 100644
--- a/arch/arm/mach-iop32x/em7210.c
+++ b/arch/arm/mach-iop32x/em7210.c
@@ -24,6 +24,7 @@
#include <linux/platform_device.h>
#include <linux/i2c.h>
#include <linux/gpio.h>
+#include <linux/gpio/machine.h>
#include <mach/hardware.h>
#include <linux/io.h>
#include <linux/irq.h>
@@ -211,6 +212,8 @@ static void __init em7210_init_machine(void)
{
register_iop32x_gpio();
platform_device_register(&em7210_serial_device);
+ gpiod_add_lookup_table(&iop3xx_i2c0_gpio_lookup);
+ gpiod_add_lookup_table(&iop3xx_i2c1_gpio_lookup);
platform_device_register(&iop3xx_i2c0_device);
platform_device_register(&iop3xx_i2c1_device);
platform_device_register(&em7210_flash_device);
diff --git a/arch/arm/mach-iop32x/glantank.c b/arch/arm/mach-iop32x/glantank.c
index 547b2342d61a..4c4995007d17 100644
--- a/arch/arm/mach-iop32x/glantank.c
+++ b/arch/arm/mach-iop32x/glantank.c
@@ -25,6 +25,7 @@
#include <linux/i2c.h>
#include <linux/platform_device.h>
#include <linux/io.h>
+#include <linux/gpio/machine.h>
#include <mach/hardware.h>
#include <asm/irq.h>
#include <asm/mach/arch.h>
@@ -189,6 +190,8 @@ static void glantank_power_off(void)
static void __init glantank_init_machine(void)
{
register_iop32x_gpio();
+ gpiod_add_lookup_table(&iop3xx_i2c0_gpio_lookup);
+ gpiod_add_lookup_table(&iop3xx_i2c1_gpio_lookup);
platform_device_register(&iop3xx_i2c0_device);
platform_device_register(&iop3xx_i2c1_device);
platform_device_register(&glantank_flash_device);
diff --git a/arch/arm/mach-iop32x/iq31244.c b/arch/arm/mach-iop32x/iq31244.c
index 0e1392b20d18..56a64ffd3824 100644
--- a/arch/arm/mach-iop32x/iq31244.c
+++ b/arch/arm/mach-iop32x/iq31244.c
@@ -26,6 +26,7 @@
#include <linux/mtd/physmap.h>
#include <linux/platform_device.h>
#include <linux/io.h>
+#include <linux/gpio/machine.h>
#include <mach/hardware.h>
#include <asm/cputype.h>
#include <asm/irq.h>
@@ -285,6 +286,8 @@ void ep80219_power_off(void)
static void __init iq31244_init_machine(void)
{
register_iop32x_gpio();
+ gpiod_add_lookup_table(&iop3xx_i2c0_gpio_lookup);
+ gpiod_add_lookup_table(&iop3xx_i2c1_gpio_lookup);
platform_device_register(&iop3xx_i2c0_device);
platform_device_register(&iop3xx_i2c1_device);
platform_device_register(&iq31244_flash_device);
diff --git a/arch/arm/mach-iop32x/iq80321.c b/arch/arm/mach-iop32x/iq80321.c
index 66782ff1f46a..02abbf9efd54 100644
--- a/arch/arm/mach-iop32x/iq80321.c
+++ b/arch/arm/mach-iop32x/iq80321.c
@@ -23,6 +23,7 @@
#include <linux/mtd/physmap.h>
#include <linux/platform_device.h>
#include <linux/io.h>
+#include <linux/gpio/machine.h>
#include <mach/hardware.h>
#include <asm/irq.h>
#include <asm/mach/arch.h>
@@ -172,6 +173,8 @@ static struct platform_device iq80321_serial_device = {
static void __init iq80321_init_machine(void)
{
register_iop32x_gpio();
+ gpiod_add_lookup_table(&iop3xx_i2c0_gpio_lookup);
+ gpiod_add_lookup_table(&iop3xx_i2c1_gpio_lookup);
platform_device_register(&iop3xx_i2c0_device);
platform_device_register(&iop3xx_i2c1_device);
platform_device_register(&iq80321_flash_device);
diff --git a/arch/arm/mach-iop32x/n2100.c b/arch/arm/mach-iop32x/n2100.c
index 23e8c93515d4..c780b6e82ad9 100644
--- a/arch/arm/mach-iop32x/n2100.c
+++ b/arch/arm/mach-iop32x/n2100.c
@@ -31,6 +31,7 @@
#include <linux/reboot.h>
#include <linux/io.h>
#include <linux/gpio.h>
+#include <linux/gpio/machine.h>
#include <mach/hardware.h>
#include <asm/irq.h>
#include <asm/mach/arch.h>
@@ -345,6 +346,7 @@ device_initcall(n2100_request_gpios);
static void __init n2100_init_machine(void)
{
register_iop32x_gpio();
+ gpiod_add_lookup_table(&iop3xx_i2c0_gpio_lookup);
platform_device_register(&iop3xx_i2c0_device);
platform_device_register(&n2100_flash_device);
platform_device_register(&n2100_serial_device);
diff --git a/arch/arm/plat-iop/i2c.c b/arch/arm/plat-iop/i2c.c
index 88215ad031a2..bac20f7f5f8a 100644
--- a/arch/arm/plat-iop/i2c.c
+++ b/arch/arm/plat-iop/i2c.c
@@ -19,6 +19,7 @@
#include <linux/tty.h>
#include <linux/serial_core.h>
#include <linux/io.h>
+#include <linux/gpio/machine.h>
#include <asm/pgtable.h>
#include <asm/page.h>
#include <asm/mach/map.h>
@@ -37,6 +38,29 @@
#define IRQ_IOP3XX_I2C_1 IRQ_IOP33X_I2C_1
#endif
+/*
+ * Each of the I2C busses have corresponding GPIO lines, and the driver
+ * need to access these directly to drive the bus low at times.
+ */
+
+struct gpiod_lookup_table iop3xx_i2c0_gpio_lookup = {
+ .dev_id = "IOP3xx-I2C.0",
+ .table = {
+ GPIO_LOOKUP("gpio-iop", 7, "scl", GPIO_ACTIVE_HIGH),
+ GPIO_LOOKUP("gpio-iop", 6, "sda", GPIO_ACTIVE_HIGH),
+ { }
+ },
+};
+
+struct gpiod_lookup_table iop3xx_i2c1_gpio_lookup = {
+ .dev_id = "IOP3xx-I2C.1",
+ .table = {
+ GPIO_LOOKUP("gpio-iop", 5, "scl", GPIO_ACTIVE_HIGH),
+ GPIO_LOOKUP("gpio-iop", 4, "sda", GPIO_ACTIVE_HIGH),
+ { }
+ },
+};
+
static struct resource iop3xx_i2c0_resources[] = {
[0] = {
.start = 0xfffff680,