[U-Boot] [PATCH V2 3/3] i2c: tegra: add standardized clk/reset API support
Stephen Warren
swarren at wwwdotorg.org
Sat Aug 6 00:10:35 CEST 2016
From: Bryan Wu <pengw at 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 at nvidia.com>
(swarren, simplified some ifdefs, removed indent level inside an ifdef)
(swarren, added comment about the ifdefs)
Signed-off-by: Stephen Warren <swarren at nvidia.com>
---
v2: Add TODO comment describing the messy ifdefs.
---
drivers/i2c/tegra_i2c.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 85 insertions(+), 4 deletions(-)
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;
}
--
2.9.2
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