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-rw-r--r--arch/arm/mach-omap2/omap_twl.c3
-rw-r--r--arch/arm/mach-omap2/pm.h2
-rw-r--r--arch/arm/mach-omap2/vc.c149
-rw-r--r--arch/arm/mach-omap2/voltage.h1
4 files changed, 147 insertions, 8 deletions
diff --git a/arch/arm/mach-omap2/omap_twl.c b/arch/arm/mach-omap2/omap_twl.c
index ecae9890f0f..611cb63d5ce 100644
--- a/arch/arm/mach-omap2/omap_twl.c
+++ b/arch/arm/mach-omap2/omap_twl.c
@@ -183,6 +183,7 @@ static struct omap_voltdm_pmic omap4_mpu_pmic = {
.volt_reg_addr = OMAP4_VDD_MPU_SR_VOLT_REG,
.cmd_reg_addr = OMAP4_VDD_MPU_SR_CMD_REG,
.i2c_high_speed = true,
+ .i2c_pad_load = 3,
.vsel_to_uv = twl6030_vsel_to_uv,
.uv_to_vsel = twl6030_uv_to_vsel,
};
@@ -200,6 +201,7 @@ static struct omap_voltdm_pmic omap4_iva_pmic = {
.volt_reg_addr = OMAP4_VDD_IVA_SR_VOLT_REG,
.cmd_reg_addr = OMAP4_VDD_IVA_SR_CMD_REG,
.i2c_high_speed = true,
+ .i2c_pad_load = 3,
.vsel_to_uv = twl6030_vsel_to_uv,
.uv_to_vsel = twl6030_uv_to_vsel,
};
@@ -216,6 +218,7 @@ static struct omap_voltdm_pmic omap4_core_pmic = {
.i2c_slave_addr = OMAP4_SRI2C_SLAVE_ADDR,
.volt_reg_addr = OMAP4_VDD_CORE_SR_VOLT_REG,
.cmd_reg_addr = OMAP4_VDD_CORE_SR_CMD_REG,
+ .i2c_pad_load = 3,
.vsel_to_uv = twl6030_vsel_to_uv,
.uv_to_vsel = twl6030_uv_to_vsel,
};
diff --git a/arch/arm/mach-omap2/pm.h b/arch/arm/mach-omap2/pm.h
index 42902885210..4db7b238a0d 100644
--- a/arch/arm/mach-omap2/pm.h
+++ b/arch/arm/mach-omap2/pm.h
@@ -132,9 +132,11 @@ static inline int omap4_twl_init(void)
#ifdef CONFIG_PM
extern void omap_pm_setup_oscillator(u32 tstart, u32 tshut);
extern void omap_pm_get_oscillator(u32 *tstart, u32 *tshut);
+extern void omap_pm_setup_sr_i2c_pcb_length(u32 mm);
#else
static inline void omap_pm_setup_oscillator(u32 tstart, u32 tshut) { }
static inline void omap_pm_get_oscillator(u32 *tstart, u32 *tshut) { }
+static inline void omap_pm_setup_sr_i2c_pcb_length(u32 mm) { }
#endif
#endif
diff --git a/arch/arm/mach-omap2/vc.c b/arch/arm/mach-omap2/vc.c
index d72b787a0d8..687aa86c0d5 100644
--- a/arch/arm/mach-omap2/vc.c
+++ b/arch/arm/mach-omap2/vc.c
@@ -24,6 +24,7 @@
#include "prm44xx.h"
#include "pm.h"
#include "scrm44xx.h"
+#include "control.h"
/**
* struct omap_vc_channel_cfg - describe the cfg_channel bitfield
@@ -69,6 +70,9 @@ static struct omap_vc_channel_cfg vc_mutant_channel_cfg = {
};
static struct omap_vc_channel_cfg *vc_cfg_bits;
+
+/* Default I2C trace length on pcb, 6.3cm. Used for capacitance calculations. */
+static u32 sr_i2c_pcb_length = 63;
#define CFG_CHANNEL_MASK 0x1f
/**
@@ -464,22 +468,135 @@ static void omap4_set_timings(struct voltagedomain *voltdm, bool off_mode)
/* OMAP4 specific voltage init functions */
static void __init omap4_vc_init_channel(struct voltagedomain *voltdm)
{
- static bool is_initialized;
- u32 vc_val;
-
omap4_set_timings(voltdm, true);
omap4_set_timings(voltdm, false);
+}
+
+struct i2c_init_data {
+ u8 loadbits;
+ u8 load;
+ u8 hsscll_38_4;
+ u8 hsscll_26;
+ u8 hsscll_19_2;
+ u8 hsscll_16_8;
+ u8 hsscll_12;
+};
+
+static const __initdata struct i2c_init_data omap4_i2c_timing_data[] = {
+ {
+ .load = 50,
+ .loadbits = 0x3,
+ .hsscll_38_4 = 13,
+ .hsscll_26 = 11,
+ .hsscll_19_2 = 9,
+ .hsscll_16_8 = 9,
+ .hsscll_12 = 8,
+ },
+ {
+ .load = 25,
+ .loadbits = 0x2,
+ .hsscll_38_4 = 13,
+ .hsscll_26 = 11,
+ .hsscll_19_2 = 9,
+ .hsscll_16_8 = 9,
+ .hsscll_12 = 8,
+ },
+ {
+ .load = 12,
+ .loadbits = 0x1,
+ .hsscll_38_4 = 11,
+ .hsscll_26 = 10,
+ .hsscll_19_2 = 9,
+ .hsscll_16_8 = 9,
+ .hsscll_12 = 8,
+ },
+ {
+ .load = 0,
+ .loadbits = 0x0,
+ .hsscll_38_4 = 12,
+ .hsscll_26 = 10,
+ .hsscll_19_2 = 9,
+ .hsscll_16_8 = 8,
+ .hsscll_12 = 8,
+ },
+};
+
+/**
+ * omap4_vc_i2c_timing_init - sets up board I2C timing parameters
+ * @voltdm: voltagedomain pointer to get data from
+ *
+ * Use PMIC + board supplied settings for calculating the total I2C
+ * channel capacitance and set the timing parameters based on this.
+ * Pre-calculated values are provided in data tables, as it is not
+ * too straightforward to calculate these runtime.
+ */
+static void __init omap4_vc_i2c_timing_init(struct voltagedomain *voltdm)
+{
+ u32 capacitance;
+ u32 val;
+ u16 hsscll;
+ const struct i2c_init_data *i2c_data;
+
+ if (!voltdm->pmic->i2c_high_speed) {
+ pr_warn("%s: only high speed supported!\n", __func__);
+ return;
+ }
- if (is_initialized)
+ /* PCB trace capacitance, 0.125pF / mm => mm / 8 */
+ capacitance = DIV_ROUND_UP(sr_i2c_pcb_length, 8);
+
+ /* OMAP pad capacitance */
+ capacitance += 4;
+
+ /* PMIC pad capacitance */
+ capacitance += voltdm->pmic->i2c_pad_load;
+
+ /* Search for capacitance match in the table */
+ i2c_data = omap4_i2c_timing_data;
+
+ while (i2c_data->load > capacitance)
+ i2c_data++;
+
+ /* Select proper values based on sysclk frequency */
+ switch (voltdm->sys_clk.rate) {
+ case 38400000:
+ hsscll = i2c_data->hsscll_38_4;
+ break;
+ case 26000000:
+ hsscll = i2c_data->hsscll_26;
+ break;
+ case 19200000:
+ hsscll = i2c_data->hsscll_19_2;
+ break;
+ case 16800000:
+ hsscll = i2c_data->hsscll_16_8;
+ break;
+ case 12000000:
+ hsscll = i2c_data->hsscll_12;
+ break;
+ default:
+ pr_warn("%s: unsupported sysclk rate: %d!\n", __func__,
+ voltdm->sys_clk.rate);
return;
+ }
+
+ /* Loadbits define pull setup for the I2C channels */
+ val = i2c_data->loadbits << 25 | i2c_data->loadbits << 29;
- /* XXX These are magic numbers and do not belong! */
- vc_val = (0x60 << OMAP4430_SCLL_SHIFT | 0x26 << OMAP4430_SCLH_SHIFT);
- voltdm->write(vc_val, OMAP4_PRM_VC_CFG_I2C_CLK_OFFSET);
+ /* Write to SYSCTRL_PADCONF_WKUP_CTRL_I2C_2 to setup I2C pull */
+ __raw_writel(val, OMAP2_L4_IO_ADDRESS(OMAP4_CTRL_MODULE_PAD_WKUP +
+ OMAP4_CTRL_MODULE_PAD_WKUP_CONTROL_I2C_2));
- is_initialized = true;
+ /* HSSCLH can always be zero */
+ val = hsscll << OMAP4430_HSSCLL_SHIFT;
+ val |= (0x28 << OMAP4430_SCLL_SHIFT | 0x2c << OMAP4430_SCLH_SHIFT);
+
+ /* Write setup times to I2C config register */
+ voltdm->write(val, OMAP4_PRM_VC_CFG_I2C_CLK_OFFSET);
}
+
+
/**
* omap_vc_i2c_init - initialize I2C interface to PMIC
* @voltdm: voltage domain containing VC data
@@ -519,6 +636,9 @@ static void __init omap_vc_i2c_init(struct voltagedomain *voltdm)
mcode << __ffs(vc->common->i2c_mcode_mask),
vc->common->i2c_cfg_reg);
+ if (cpu_is_omap44xx())
+ omap4_vc_i2c_timing_init(voltdm);
+
initialized = true;
}
@@ -546,6 +666,19 @@ static u8 omap_vc_calc_vsel(struct voltagedomain *voltdm, u32 uvolt)
return voltdm->pmic->uv_to_vsel(uvolt);
}
+/**
+ * omap_pm_setup_sr_i2c_pcb_length - set length of SR I2C traces on PCB
+ * @mm: length of the PCB trace in millimetres
+ *
+ * Sets the PCB trace length for the I2C channel. By default uses 63mm.
+ * This is needed for properly calculating the capacitance value for
+ * the PCB trace, and for setting the SR I2C channel timing parameters.
+ */
+void __init omap_pm_setup_sr_i2c_pcb_length(u32 mm)
+{
+ sr_i2c_pcb_length = mm;
+}
+
void __init omap_vc_init_channel(struct voltagedomain *voltdm)
{
struct omap_vc_channel *vc = voltdm->vc;
diff --git a/arch/arm/mach-omap2/voltage.h b/arch/arm/mach-omap2/voltage.h
index 78923f93efd..a0ce4f10ff1 100644
--- a/arch/arm/mach-omap2/voltage.h
+++ b/arch/arm/mach-omap2/voltage.h
@@ -139,6 +139,7 @@ struct omap_voltdm_pmic {
u32 vddmax;
u8 vp_timeout_us;
bool i2c_high_speed;
+ u32 i2c_pad_load;
u8 i2c_mcode;
unsigned long (*vsel_to_uv) (const u8 vsel);
u8 (*uv_to_vsel) (unsigned long uV);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-12 17:16:18 +0000