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

Gregory CLEMENT
2016-11-08T15:44:14Z

Hi Romain,

On mar., nov. 08 2016, Romain Perier <romain.perier@free-electrons.com> wrote:

> 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.

On the Armada 3720 DB board I manged to run i2cdetect and did some
i2cdump successfully.

Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com>

During the kernel init I got a:
pxa2xx-i2c d0011000.i2c: failed to get the clk: -517

Maybe an improvement of the driver could be to not output this message
in case of EPROBE_DEFER. Or at least an other message less scary.

Thanks,

Gregory

>
> Signed-off-by: Romain Perier <romain.perier@free-electrons.com>
> ---
> 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
>

--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.