[PATCH 1/3] i2c: pxa: Add support for the I2C units found in Armada 3700

Romain Perier
2016-11-08T15:15:04Z

The Armada 3700 has two I2C controllers that is compliant with the I2C
Bus Specificiation 2.1, supports multi-master and different bus speed:
Standard mode (up to 100 KHz), Fast mode (up to 400 KHz),
High speed mode (up to 3.4 Mhz).

This IP block has a lot of similarity with the PXA, except some register
offsets and bitfield. This commits adds a basic support for this I2C
unit.

Signed-off-by: Romain Perier <romain.perier-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
---
drivers/i2c/busses/Kconfig | 2 +-
drivers/i2c/busses/i2c-pxa.c | 25 +++++++++++++++++++++++--
2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index d252276..2f56a26 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -763,7 +763,7 @@ config I2C_PUV3

config I2C_PXA
tristate "Intel PXA2XX I2C adapter"
- depends on ARCH_PXA || ARCH_MMP || (X86_32 && PCI && OF)
+ depends on ARCH_PXA || ARCH_MMP || ARCH_MVEBU || (X86_32 && PCI && OF)
help
If you have devices in the PXA I2C bus, say yes to this option.
This driver can also be built as a module. If so, the module
diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
index e28b825..34ea830 100644
--- a/drivers/i2c/busses/i2c-pxa.c
+++ b/drivers/i2c/busses/i2c-pxa.c
@@ -55,6 +55,7 @@ enum pxa_i2c_types {
REGS_PXA3XX,
REGS_CE4100,
REGS_PXA910,
+ REGS_A3700,
};

/*
@@ -91,6 +92,13 @@ static struct pxa_reg_layout pxa_reg_layout[] = {
.ilcr = 0x28,
.iwcr = 0x30,
},
+ [REGS_A3700] = {
+ .ibmr = 0x00,
+ .idbr = 0x04,
+ .icr = 0x08,
+ .isr = 0x0c,
+ .isar = 0x10,
+ },
};

static const struct platform_device_id i2c_pxa_id_table[] = {
@@ -98,6 +106,7 @@ static const struct platform_device_id i2c_pxa_id_table[] = {
{ "pxa3xx-pwri2c", REGS_PXA3XX },
{ "ce4100-i2c", REGS_CE4100 },
{ "pxa910-i2c", REGS_PXA910 },
+ { "armada-3700-i2c", REGS_A3700 },
{ },
};
MODULE_DEVICE_TABLE(platform, i2c_pxa_id_table);
@@ -122,7 +131,9 @@ MODULE_DEVICE_TABLE(platform, i2c_pxa_id_table);
#define ICR_SADIE (1 << 13) /* slave address detected int enable */
#define ICR_UR (1 << 14) /* unit reset */
#define ICR_FM (1 << 15) /* fast mode */
+#define ICR_BUSMODE_FM (1 << 16) /* shifted fast mode for armada-3700 */
#define ICR_HS (1 << 16) /* High Speed mode */
+#define ICR_BUSMODE_HS (1 << 17) /* shifted high speed mode for armada-3700 */
#define ICR_GPIOEN (1 << 19) /* enable GPIO mode for SCL in HS */

#define ISR_RWM (1 << 0) /* read/write mode */
@@ -193,6 +204,8 @@ struct pxa_i2c {
unsigned char master_code;
unsigned long rate;
bool highmode_enter;
+ unsigned long fm_mask;
+ unsigned long hs_mask;
};

#define _IBMR(i2c) ((i2c)->reg_ibmr)
@@ -503,8 +516,8 @@ static void i2c_pxa_reset(struct pxa_i2c *i2c)
writel(i2c->slave_addr, _ISAR(i2c));

/* set control register values */
- writel(I2C_ICR_INIT | (i2c->fast_mode ? ICR_FM : 0), _ICR(i2c));
- writel(readl(_ICR(i2c)) | (i2c->high_mode ? ICR_HS : 0), _ICR(i2c));
+ writel(I2C_ICR_INIT | (i2c->fast_mode ? i2c->fm_mask : 0), _ICR(i2c));
+ writel(readl(_ICR(i2c)) | (i2c->high_mode ? i2c->hs_mask : 0), _ICR(i2c));

#ifdef CONFIG_I2C_PXA_SLAVE
dev_info(&i2c->adap.dev, "Enabling slave mode\n");
@@ -1137,6 +1150,7 @@ static const struct of_device_id i2c_pxa_dt_ids[] = {
{ .compatible = "mrvl,pxa-i2c", .data = (void *)REGS_PXA2XX },
{ .compatible = "mrvl,pwri2c", .data = (void *)REGS_PXA3XX },
{ .compatible = "mrvl,mmp-twsi", .data = (void *)REGS_PXA910 },
+ { .compatible = "marvell,armada-3700-i2c", .data = (void *)REGS_A3700 },
{}
};
MODULE_DEVICE_TABLE(of, i2c_pxa_dt_ids);
@@ -1158,6 +1172,13 @@ static int i2c_pxa_probe_dt(struct platform_device *pdev, struct pxa_i2c *i2c,
i2c->use_pio = 1;
if (of_get_property(np, "mrvl,i2c-fast-mode", NULL))
i2c->fast_mode = 1;
+ if (of_device_is_compatible(np, "marvell,armada-3700-i2c")) {
+ i2c->fm_mask = ICR_BUSMODE_FM;
+ i2c->hs_mask = ICR_BUSMODE_HS;
+ } else {
+ i2c->fm_mask = ICR_FM;
+ i2c->hs_mask = ICR_HS;
+ }

*i2c_types = (enum pxa_i2c_types)(of_id->data);

--
2.9.3

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