[U-Boot] [PATCH V2 3/3] i2c: tegra: add standardized clk/reset API support

[Heiko Schocher <hs@denx.de>]

Hello Stephen,

Am 06.08.2016 um 00:10 schrieb Stephen Warren:
> From: Bryan Wu <pengw@nvidia.com>
>
> clk/reset API was tested on T186 platform and previous chip like
> T210/T124 will still use the old APIs.
>
> Signed-off-by: Bryan Wu <pengw@nvidia.com>
> (swarren, simplified some ifdefs, removed indent level inside an ifdef)
> (swarren, added comment about the ifdefs)
> Signed-off-by: Stephen Warren <swarren@nvidia.com>
> ---
> v2: Add TODO comment describing the messy ifdefs.
> ---
>   drivers/i2c/tegra_i2c.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++---
>   1 file changed, 85 insertions(+), 4 deletions(-)

Reviewed-by: Heiko Schocher <hs@denx.de>

bye,
Heiko
>
> diff --git a/drivers/i2c/tegra_i2c.c b/drivers/i2c/tegra_i2c.c
> index 2fa07f9c57c4..31ba263b7295 100644
> --- a/drivers/i2c/tegra_i2c.c
> +++ b/drivers/i2c/tegra_i2c.c
> @@ -12,13 +12,27 @@
>   #include <fdtdec.h>
>   #include <i2c.h>
>   #include <asm/io.h>
> +#ifdef CONFIG_TEGRA186
> +#include <clk.h>
> +#include <reset.h>
> +#else
>   #include <asm/arch/clock.h>
>   #include <asm/arch/funcmux.h>
> -#include <asm/arch/gpio.h>
>   #include <asm/arch/pinmux.h>
>   #include <asm/arch-tegra/clk_rst.h>
> +#endif
> +#include <asm/arch/gpio.h>
>   #include <asm/arch-tegra/tegra_i2c.h>
>
> +/*
> + * FIXME: TODO: This driver contains a number of ifdef CONFIG_TEGRA186 that
> + * should not be present. These are needed because newer Tegra SoCs support
> + * only the standard clock/reset APIs, whereas older Tegra SoCs support only
> + * a custom Tegra-specific API. ASAP the older Tegra SoCs' code should be
> + * fixed to implement the standard APIs, and all drivers converted to solely
> + * use the new standard APIs, with no ifdefs.
> + */
> +
>   DECLARE_GLOBAL_DATA_PTR;
>
>   enum i2c_type {
> @@ -30,7 +44,12 @@ enum i2c_type {
>   /* Information about i2c controller */
>   struct i2c_bus {
>   	int			id;
> +#ifdef CONFIG_TEGRA186
> +	struct reset_ctl	reset_ctl;
> +	struct clk		clk;
> +#else
>   	enum periph_id		periph_id;
> +#endif
>   	int			speed;
>   	int			pinmux_config;
>   	struct i2c_control	*control;
> @@ -62,12 +81,41 @@ static void set_packet_mode(struct i2c_bus *i2c_bus)
>   static void i2c_reset_controller(struct i2c_bus *i2c_bus)
>   {
>   	/* Reset I2C controller. */
> +#ifdef CONFIG_TEGRA186
> +	reset_assert(&i2c_bus->reset_ctl);
> +	udelay(1);
> +	reset_deassert(&i2c_bus->reset_ctl);
> +	udelay(1);
> +#else
>   	reset_periph(i2c_bus->periph_id, 1);
> +#endif
>
>   	/* re-program config register to packet mode */
>   	set_packet_mode(i2c_bus);
>   }
>
> +#ifdef CONFIG_TEGRA186
> +static int i2c_init_clock(struct i2c_bus *i2c_bus, unsigned rate)
> +{
> +	int ret;
> +
> +	ret = reset_assert(&i2c_bus->reset_ctl);
> +	if (ret)
> +		return ret;
> +	ret = clk_enable(&i2c_bus->clk);
> +	if (ret)
> +		return ret;
> +	ret = clk_set_rate(&i2c_bus->clk, rate);
> +	if (IS_ERR_VALUE(ret))
> +		return ret;
> +	ret = reset_deassert(&i2c_bus->reset_ctl);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +#endif
> +
>   static void i2c_init_controller(struct i2c_bus *i2c_bus)
>   {
>   	if (!i2c_bus->speed)
> @@ -78,8 +126,12 @@ static void i2c_init_controller(struct i2c_bus *i2c_bus)
>   	 * here, in section 23.3.1, but in fact we seem to need a factor of
>   	 * 16 to get the right frequency.
>   	 */
> +#ifdef CONFIG_TEGRA186
> +	i2c_init_clock(i2c_bus, i2c_bus->speed * 2 * 8);
> +#else
>   	clock_start_periph_pll(i2c_bus->periph_id, CLOCK_ID_PERIPH,
>   		i2c_bus->speed * 2 * 8);
> +#endif
>
>   	if (i2c_bus->type == TYPE_114) {
>   		/*
> @@ -94,12 +146,17 @@ static void i2c_init_controller(struct i2c_bus *i2c_bus)
>   		 * is running, we hang, and we need it for the new calc.
>   		 */
>   		int clk_div_stdfst_mode = readl(&i2c_bus->regs->clk_div) >> 16;
> +		unsigned rate = CLK_MULT_STD_FAST_MODE *
> +				(clk_div_stdfst_mode + 1) * i2c_bus->speed * 2;
>   		debug("%s: CLK_DIV_STD_FAST_MODE setting = %d\n", __func__,
>   			clk_div_stdfst_mode);
>
> +#ifdef CONFIG_TEGRA186
> +		i2c_init_clock(i2c_bus, rate);
> +#else
>   		clock_start_periph_pll(i2c_bus->periph_id, CLOCK_ID_PERIPH,
> -			CLK_MULT_STD_FAST_MODE * (clk_div_stdfst_mode + 1) *
> -			i2c_bus->speed * 2);
> +				       rate);
> +#endif
>   	}
>
>   	/* Reset I2C controller. */
> @@ -112,7 +169,9 @@ static void i2c_init_controller(struct i2c_bus *i2c_bus)
>   		setbits_le32(&dvc->ctrl3, DVC_CTRL_REG3_I2C_HW_SW_PROG_MASK);
>   	}
>
> +#ifndef CONFIG_TEGRA186
>   	funcmux_select(i2c_bus->periph_id, i2c_bus->pinmux_config);
> +#endif
>   }
>
>   static void send_packet_headers(
> @@ -333,8 +392,12 @@ static int tegra_i2c_set_bus_speed(struct udevice *dev, unsigned int speed)
>   static int tegra_i2c_probe(struct udevice *dev)
>   {
>   	struct i2c_bus *i2c_bus = dev_get_priv(dev);
> +#ifdef CONFIG_TEGRA186
> +	int ret;
> +#else
>   	const void *blob = gd->fdt_blob;
>   	int node = dev->of_offset;
> +#endif
>   	bool is_dvc;
>
>   	i2c_bus->id = dev->seq;
> @@ -345,6 +408,18 @@ static int tegra_i2c_probe(struct udevice *dev)
>   	 * We don't have a binding for pinmux yet. Leave it out for now. So
>   	 * far no one needs anything other than the default.
>   	 */
> +#ifdef CONFIG_TEGRA186
> +	ret = reset_get_by_name(dev, "i2c", &i2c_bus->reset_ctl);
> +	if (ret) {
> +		error("reset_get_by_name() failed: %d\n", ret);
> +		return ret;
> +	}
> +	ret = clk_get_by_name(dev, "i2c", &i2c_bus->clk);
> +	if (ret) {
> +		error("clk_get_by_name() failed: %d\n", ret);
> +		return ret;
> +	}
> +#else
>   	i2c_bus->pinmux_config = FUNCMUX_DEFAULT;
>   	i2c_bus->periph_id = clock_decode_periph_id(blob, node);
>
> @@ -359,6 +434,7 @@ static int tegra_i2c_probe(struct udevice *dev)
>   	 */
>   	if (i2c_bus->periph_id == -1)
>   		return -EINVAL;
> +#endif
>
>   	is_dvc = dev_get_driver_data(dev) == TYPE_DVC;
>   	if (is_dvc) {
> @@ -370,7 +446,12 @@ static int tegra_i2c_probe(struct udevice *dev)
>   	i2c_init_controller(i2c_bus);
>   	debug("%s: controller bus %d at %p, periph_id %d, speed %d: ",
>   	      is_dvc ? "dvc" : "i2c", dev->seq, i2c_bus->regs,
> -	      i2c_bus->periph_id, i2c_bus->speed);
> +#ifndef CONFIG_TEGRA186
> +	      i2c_bus->periph_id,
> +#else
> +	      -1,
> +#endif
> +	      i2c_bus->speed);
>
>   	return 0;
>   }
>

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