mirror of
https://github.com/AsahiLinux/u-boot
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499504ba06
This patch solves the following warnings: drivers/i2c/stm32f7_i2c.c: In function 'stm32_i2c_compute_solutions': warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (scldel < scldel_min) ^ warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (((sdadel >= sdadel_min) && ^~ warning: comparison between signed and unsigned integer expressions [-Wsign-compare] (sdadel <= sdadel_max)) && ^~ drivers/i2c/stm32f7_i2c.c: In function 'stm32_i2c_choose_solution': warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (clk_error < clk_error_prev) { ^ Signed-off-by: Patrice Chotard <patrice.chotard@st.com> Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
881 lines
22 KiB
C
881 lines
22 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* (C) Copyright 2017 STMicroelectronics
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*/
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#include <common.h>
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#include <clk.h>
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#include <dm.h>
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#include <i2c.h>
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#include <reset.h>
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#include <dm/device.h>
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#include <linux/io.h>
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/* STM32 I2C registers */
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struct stm32_i2c_regs {
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u32 cr1; /* I2C control register 1 */
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u32 cr2; /* I2C control register 2 */
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u32 oar1; /* I2C own address 1 register */
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u32 oar2; /* I2C own address 2 register */
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u32 timingr; /* I2C timing register */
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u32 timeoutr; /* I2C timeout register */
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u32 isr; /* I2C interrupt and status register */
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u32 icr; /* I2C interrupt clear register */
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u32 pecr; /* I2C packet error checking register */
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u32 rxdr; /* I2C receive data register */
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u32 txdr; /* I2C transmit data register */
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};
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#define STM32_I2C_CR1 0x00
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#define STM32_I2C_CR2 0x04
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#define STM32_I2C_TIMINGR 0x10
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#define STM32_I2C_ISR 0x18
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#define STM32_I2C_ICR 0x1C
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#define STM32_I2C_RXDR 0x24
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#define STM32_I2C_TXDR 0x28
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/* STM32 I2C control 1 */
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#define STM32_I2C_CR1_ANFOFF BIT(12)
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#define STM32_I2C_CR1_ERRIE BIT(7)
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#define STM32_I2C_CR1_TCIE BIT(6)
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#define STM32_I2C_CR1_STOPIE BIT(5)
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#define STM32_I2C_CR1_NACKIE BIT(4)
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#define STM32_I2C_CR1_ADDRIE BIT(3)
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#define STM32_I2C_CR1_RXIE BIT(2)
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#define STM32_I2C_CR1_TXIE BIT(1)
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#define STM32_I2C_CR1_PE BIT(0)
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/* STM32 I2C control 2 */
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#define STM32_I2C_CR2_AUTOEND BIT(25)
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#define STM32_I2C_CR2_RELOAD BIT(24)
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#define STM32_I2C_CR2_NBYTES_MASK GENMASK(23, 16)
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#define STM32_I2C_CR2_NBYTES(n) ((n & 0xff) << 16)
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#define STM32_I2C_CR2_NACK BIT(15)
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#define STM32_I2C_CR2_STOP BIT(14)
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#define STM32_I2C_CR2_START BIT(13)
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#define STM32_I2C_CR2_HEAD10R BIT(12)
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#define STM32_I2C_CR2_ADD10 BIT(11)
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#define STM32_I2C_CR2_RD_WRN BIT(10)
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#define STM32_I2C_CR2_SADD10_MASK GENMASK(9, 0)
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#define STM32_I2C_CR2_SADD10(n) (n & STM32_I2C_CR2_SADD10_MASK)
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#define STM32_I2C_CR2_SADD7_MASK GENMASK(7, 1)
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#define STM32_I2C_CR2_SADD7(n) ((n & 0x7f) << 1)
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#define STM32_I2C_CR2_RESET_MASK (STM32_I2C_CR2_HEAD10R \
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| STM32_I2C_CR2_NBYTES_MASK \
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| STM32_I2C_CR2_SADD7_MASK \
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| STM32_I2C_CR2_RELOAD \
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| STM32_I2C_CR2_RD_WRN)
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/* STM32 I2C Interrupt Status */
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#define STM32_I2C_ISR_BUSY BIT(15)
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#define STM32_I2C_ISR_ARLO BIT(9)
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#define STM32_I2C_ISR_BERR BIT(8)
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#define STM32_I2C_ISR_TCR BIT(7)
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#define STM32_I2C_ISR_TC BIT(6)
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#define STM32_I2C_ISR_STOPF BIT(5)
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#define STM32_I2C_ISR_NACKF BIT(4)
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#define STM32_I2C_ISR_ADDR BIT(3)
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#define STM32_I2C_ISR_RXNE BIT(2)
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#define STM32_I2C_ISR_TXIS BIT(1)
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#define STM32_I2C_ISR_TXE BIT(0)
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#define STM32_I2C_ISR_ERRORS (STM32_I2C_ISR_BERR \
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| STM32_I2C_ISR_ARLO)
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/* STM32 I2C Interrupt Clear */
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#define STM32_I2C_ICR_ARLOCF BIT(9)
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#define STM32_I2C_ICR_BERRCF BIT(8)
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#define STM32_I2C_ICR_STOPCF BIT(5)
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#define STM32_I2C_ICR_NACKCF BIT(4)
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/* STM32 I2C Timing */
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#define STM32_I2C_TIMINGR_PRESC(n) ((n & 0xf) << 28)
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#define STM32_I2C_TIMINGR_SCLDEL(n) ((n & 0xf) << 20)
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#define STM32_I2C_TIMINGR_SDADEL(n) ((n & 0xf) << 16)
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#define STM32_I2C_TIMINGR_SCLH(n) ((n & 0xff) << 8)
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#define STM32_I2C_TIMINGR_SCLL(n) (n & 0xff)
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#define STM32_I2C_MAX_LEN 0xff
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#define STM32_I2C_DNF_DEFAULT 0
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#define STM32_I2C_DNF_MAX 16
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#define STM32_I2C_ANALOG_FILTER_ENABLE 1
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#define STM32_I2C_ANALOG_FILTER_DELAY_MIN 50 /* ns */
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#define STM32_I2C_ANALOG_FILTER_DELAY_MAX 260 /* ns */
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#define STM32_I2C_RISE_TIME_DEFAULT 25 /* ns */
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#define STM32_I2C_FALL_TIME_DEFAULT 10 /* ns */
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#define STM32_PRESC_MAX BIT(4)
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#define STM32_SCLDEL_MAX BIT(4)
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#define STM32_SDADEL_MAX BIT(4)
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#define STM32_SCLH_MAX BIT(8)
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#define STM32_SCLL_MAX BIT(8)
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#define STM32_NSEC_PER_SEC 1000000000L
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#define STANDARD_RATE 100000
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#define FAST_RATE 400000
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#define FAST_PLUS_RATE 1000000
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enum stm32_i2c_speed {
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STM32_I2C_SPEED_STANDARD, /* 100 kHz */
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STM32_I2C_SPEED_FAST, /* 400 kHz */
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STM32_I2C_SPEED_FAST_PLUS, /* 1 MHz */
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STM32_I2C_SPEED_END,
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};
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/**
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* struct stm32_i2c_spec - private i2c specification timing
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* @rate: I2C bus speed (Hz)
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* @rate_min: 80% of I2C bus speed (Hz)
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* @rate_max: 120% of I2C bus speed (Hz)
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* @fall_max: Max fall time of both SDA and SCL signals (ns)
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* @rise_max: Max rise time of both SDA and SCL signals (ns)
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* @hddat_min: Min data hold time (ns)
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* @vddat_max: Max data valid time (ns)
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* @sudat_min: Min data setup time (ns)
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* @l_min: Min low period of the SCL clock (ns)
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* @h_min: Min high period of the SCL clock (ns)
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*/
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struct stm32_i2c_spec {
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u32 rate;
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u32 rate_min;
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u32 rate_max;
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u32 fall_max;
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u32 rise_max;
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u32 hddat_min;
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u32 vddat_max;
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u32 sudat_min;
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u32 l_min;
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u32 h_min;
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};
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/**
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* struct stm32_i2c_setup - private I2C timing setup parameters
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* @speed: I2C speed mode (standard, Fast Plus)
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* @speed_freq: I2C speed frequency (Hz)
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* @clock_src: I2C clock source frequency (Hz)
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* @rise_time: Rise time (ns)
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* @fall_time: Fall time (ns)
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* @dnf: Digital filter coefficient (0-16)
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* @analog_filter: Analog filter delay (On/Off)
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*/
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struct stm32_i2c_setup {
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enum stm32_i2c_speed speed;
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u32 speed_freq;
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u32 clock_src;
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u32 rise_time;
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u32 fall_time;
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u8 dnf;
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bool analog_filter;
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};
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/**
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* struct stm32_i2c_timings - private I2C output parameters
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* @prec: Prescaler value
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* @scldel: Data setup time
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* @sdadel: Data hold time
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* @sclh: SCL high period (master mode)
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* @sclh: SCL low period (master mode)
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*/
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struct stm32_i2c_timings {
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struct list_head node;
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u8 presc;
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u8 scldel;
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u8 sdadel;
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u8 sclh;
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u8 scll;
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};
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struct stm32_i2c_priv {
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struct stm32_i2c_regs *regs;
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struct clk clk;
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struct stm32_i2c_setup *setup;
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int speed;
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};
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static const struct stm32_i2c_spec i2c_specs[] = {
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[STM32_I2C_SPEED_STANDARD] = {
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.rate = STANDARD_RATE,
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.rate_min = 8000,
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.rate_max = 120000,
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.fall_max = 300,
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.rise_max = 1000,
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.hddat_min = 0,
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.vddat_max = 3450,
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.sudat_min = 250,
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.l_min = 4700,
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.h_min = 4000,
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},
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[STM32_I2C_SPEED_FAST] = {
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.rate = FAST_RATE,
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.rate_min = 320000,
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.rate_max = 480000,
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.fall_max = 300,
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.rise_max = 300,
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.hddat_min = 0,
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.vddat_max = 900,
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.sudat_min = 100,
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.l_min = 1300,
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.h_min = 600,
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},
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[STM32_I2C_SPEED_FAST_PLUS] = {
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.rate = FAST_PLUS_RATE,
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.rate_min = 800000,
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.rate_max = 1200000,
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.fall_max = 100,
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.rise_max = 120,
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.hddat_min = 0,
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.vddat_max = 450,
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.sudat_min = 50,
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.l_min = 500,
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.h_min = 260,
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},
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};
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static const struct stm32_i2c_setup stm32f7_setup = {
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.rise_time = STM32_I2C_RISE_TIME_DEFAULT,
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.fall_time = STM32_I2C_FALL_TIME_DEFAULT,
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.dnf = STM32_I2C_DNF_DEFAULT,
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.analog_filter = STM32_I2C_ANALOG_FILTER_ENABLE,
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};
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static int stm32_i2c_check_device_busy(struct stm32_i2c_priv *i2c_priv)
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{
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struct stm32_i2c_regs *regs = i2c_priv->regs;
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u32 status = readl(®s->isr);
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if (status & STM32_I2C_ISR_BUSY)
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return -EBUSY;
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return 0;
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}
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static void stm32_i2c_message_start(struct stm32_i2c_priv *i2c_priv,
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struct i2c_msg *msg, bool stop)
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{
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struct stm32_i2c_regs *regs = i2c_priv->regs;
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u32 cr2 = readl(®s->cr2);
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/* Set transfer direction */
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cr2 &= ~STM32_I2C_CR2_RD_WRN;
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if (msg->flags & I2C_M_RD)
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cr2 |= STM32_I2C_CR2_RD_WRN;
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/* Set slave address */
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cr2 &= ~(STM32_I2C_CR2_HEAD10R | STM32_I2C_CR2_ADD10);
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if (msg->flags & I2C_M_TEN) {
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cr2 &= ~STM32_I2C_CR2_SADD10_MASK;
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cr2 |= STM32_I2C_CR2_SADD10(msg->addr);
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cr2 |= STM32_I2C_CR2_ADD10;
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} else {
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cr2 &= ~STM32_I2C_CR2_SADD7_MASK;
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cr2 |= STM32_I2C_CR2_SADD7(msg->addr);
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}
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/* Set nb bytes to transfer and reload or autoend bits */
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cr2 &= ~(STM32_I2C_CR2_NBYTES_MASK | STM32_I2C_CR2_RELOAD |
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STM32_I2C_CR2_AUTOEND);
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if (msg->len > STM32_I2C_MAX_LEN) {
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cr2 |= STM32_I2C_CR2_NBYTES(STM32_I2C_MAX_LEN);
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cr2 |= STM32_I2C_CR2_RELOAD;
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} else {
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cr2 |= STM32_I2C_CR2_NBYTES(msg->len);
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}
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/* Write configurations register */
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writel(cr2, ®s->cr2);
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/* START/ReSTART generation */
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setbits_le32(®s->cr2, STM32_I2C_CR2_START);
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}
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/*
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* RELOAD mode must be selected if total number of data bytes to be
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* sent is greater than MAX_LEN
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*/
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static void stm32_i2c_handle_reload(struct stm32_i2c_priv *i2c_priv,
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struct i2c_msg *msg, bool stop)
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{
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struct stm32_i2c_regs *regs = i2c_priv->regs;
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u32 cr2 = readl(®s->cr2);
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cr2 &= ~STM32_I2C_CR2_NBYTES_MASK;
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if (msg->len > STM32_I2C_MAX_LEN) {
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cr2 |= STM32_I2C_CR2_NBYTES(STM32_I2C_MAX_LEN);
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} else {
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cr2 &= ~STM32_I2C_CR2_RELOAD;
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cr2 |= STM32_I2C_CR2_NBYTES(msg->len);
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}
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writel(cr2, ®s->cr2);
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}
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static int stm32_i2c_wait_flags(struct stm32_i2c_priv *i2c_priv,
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u32 flags, u32 *status)
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{
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struct stm32_i2c_regs *regs = i2c_priv->regs;
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u32 time_start = get_timer(0);
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*status = readl(®s->isr);
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while (!(*status & flags)) {
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if (get_timer(time_start) > CONFIG_SYS_HZ) {
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debug("%s: i2c timeout\n", __func__);
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return -ETIMEDOUT;
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}
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*status = readl(®s->isr);
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}
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return 0;
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}
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static int stm32_i2c_check_end_of_message(struct stm32_i2c_priv *i2c_priv)
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{
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struct stm32_i2c_regs *regs = i2c_priv->regs;
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u32 mask = STM32_I2C_ISR_ERRORS | STM32_I2C_ISR_NACKF |
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STM32_I2C_ISR_STOPF;
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u32 status;
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int ret;
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ret = stm32_i2c_wait_flags(i2c_priv, mask, &status);
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if (ret)
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return ret;
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if (status & STM32_I2C_ISR_BERR) {
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debug("%s: Bus error\n", __func__);
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/* Clear BERR flag */
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setbits_le32(®s->icr, STM32_I2C_ICR_BERRCF);
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return -EIO;
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}
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if (status & STM32_I2C_ISR_ARLO) {
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debug("%s: Arbitration lost\n", __func__);
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/* Clear ARLO flag */
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setbits_le32(®s->icr, STM32_I2C_ICR_ARLOCF);
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return -EAGAIN;
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}
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if (status & STM32_I2C_ISR_NACKF) {
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debug("%s: Receive NACK\n", __func__);
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/* Clear NACK flag */
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setbits_le32(®s->icr, STM32_I2C_ICR_NACKCF);
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/* Wait until STOPF flag is set */
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mask = STM32_I2C_ISR_STOPF;
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ret = stm32_i2c_wait_flags(i2c_priv, mask, &status);
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if (ret)
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return ret;
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ret = -EIO;
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}
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if (status & STM32_I2C_ISR_STOPF) {
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/* Clear STOP flag */
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setbits_le32(®s->icr, STM32_I2C_ICR_STOPCF);
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/* Clear control register 2 */
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setbits_le32(®s->cr2, STM32_I2C_CR2_RESET_MASK);
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}
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return ret;
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}
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static int stm32_i2c_message_xfer(struct stm32_i2c_priv *i2c_priv,
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struct i2c_msg *msg, bool stop)
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{
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struct stm32_i2c_regs *regs = i2c_priv->regs;
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u32 status;
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u32 mask = msg->flags & I2C_M_RD ? STM32_I2C_ISR_RXNE :
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STM32_I2C_ISR_TXIS | STM32_I2C_ISR_NACKF;
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int bytes_to_rw = msg->len > STM32_I2C_MAX_LEN ?
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STM32_I2C_MAX_LEN : msg->len;
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int ret = 0;
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/* Add errors */
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mask |= STM32_I2C_ISR_ERRORS;
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stm32_i2c_message_start(i2c_priv, msg, stop);
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while (msg->len) {
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/*
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* Wait until TXIS/NACKF/BERR/ARLO flags or
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* RXNE/BERR/ARLO flags are set
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*/
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ret = stm32_i2c_wait_flags(i2c_priv, mask, &status);
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if (ret)
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break;
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if (status & (STM32_I2C_ISR_NACKF | STM32_I2C_ISR_ERRORS))
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break;
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if (status & STM32_I2C_ISR_RXNE) {
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*msg->buf++ = readb(®s->rxdr);
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msg->len--;
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bytes_to_rw--;
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}
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if (status & STM32_I2C_ISR_TXIS) {
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writeb(*msg->buf++, ®s->txdr);
|
|
msg->len--;
|
|
bytes_to_rw--;
|
|
}
|
|
|
|
if (!bytes_to_rw && msg->len) {
|
|
/* Wait until TCR flag is set */
|
|
mask = STM32_I2C_ISR_TCR;
|
|
ret = stm32_i2c_wait_flags(i2c_priv, mask, &status);
|
|
if (ret)
|
|
break;
|
|
|
|
bytes_to_rw = msg->len > STM32_I2C_MAX_LEN ?
|
|
STM32_I2C_MAX_LEN : msg->len;
|
|
mask = msg->flags & I2C_M_RD ? STM32_I2C_ISR_RXNE :
|
|
STM32_I2C_ISR_TXIS | STM32_I2C_ISR_NACKF;
|
|
|
|
stm32_i2c_handle_reload(i2c_priv, msg, stop);
|
|
} else if (!bytes_to_rw) {
|
|
/* Wait until TC flag is set */
|
|
mask = STM32_I2C_ISR_TC;
|
|
ret = stm32_i2c_wait_flags(i2c_priv, mask, &status);
|
|
if (ret)
|
|
break;
|
|
|
|
if (!stop)
|
|
/* Message sent, new message has to be sent */
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/* End of transfer, send stop condition */
|
|
mask = STM32_I2C_CR2_STOP;
|
|
setbits_le32(®s->cr2, mask);
|
|
|
|
return stm32_i2c_check_end_of_message(i2c_priv);
|
|
}
|
|
|
|
static int stm32_i2c_xfer(struct udevice *bus, struct i2c_msg *msg,
|
|
int nmsgs)
|
|
{
|
|
struct stm32_i2c_priv *i2c_priv = dev_get_priv(bus);
|
|
int ret;
|
|
|
|
ret = stm32_i2c_check_device_busy(i2c_priv);
|
|
if (ret)
|
|
return ret;
|
|
|
|
for (; nmsgs > 0; nmsgs--, msg++) {
|
|
ret = stm32_i2c_message_xfer(i2c_priv, msg, nmsgs == 1);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int stm32_i2c_compute_solutions(struct stm32_i2c_setup *setup,
|
|
struct list_head *solutions)
|
|
{
|
|
struct stm32_i2c_timings *v;
|
|
u32 p_prev = STM32_PRESC_MAX;
|
|
u32 i2cclk = DIV_ROUND_CLOSEST(STM32_NSEC_PER_SEC,
|
|
setup->clock_src);
|
|
u32 af_delay_min, af_delay_max;
|
|
u16 p, l, a;
|
|
int sdadel_min, sdadel_max, scldel_min;
|
|
int ret = 0;
|
|
|
|
af_delay_min = setup->analog_filter ?
|
|
STM32_I2C_ANALOG_FILTER_DELAY_MIN : 0;
|
|
af_delay_max = setup->analog_filter ?
|
|
STM32_I2C_ANALOG_FILTER_DELAY_MAX : 0;
|
|
|
|
sdadel_min = i2c_specs[setup->speed].hddat_min + setup->fall_time -
|
|
af_delay_min - (setup->dnf + 3) * i2cclk;
|
|
|
|
sdadel_max = i2c_specs[setup->speed].vddat_max - setup->rise_time -
|
|
af_delay_max - (setup->dnf + 4) * i2cclk;
|
|
|
|
scldel_min = setup->rise_time + i2c_specs[setup->speed].sudat_min;
|
|
|
|
if (sdadel_min < 0)
|
|
sdadel_min = 0;
|
|
if (sdadel_max < 0)
|
|
sdadel_max = 0;
|
|
|
|
debug("%s: SDADEL(min/max): %i/%i, SCLDEL(Min): %i\n", __func__,
|
|
sdadel_min, sdadel_max, scldel_min);
|
|
|
|
/* Compute possible values for PRESC, SCLDEL and SDADEL */
|
|
for (p = 0; p < STM32_PRESC_MAX; p++) {
|
|
for (l = 0; l < STM32_SCLDEL_MAX; l++) {
|
|
int scldel = (l + 1) * (p + 1) * i2cclk;
|
|
|
|
if (scldel < scldel_min)
|
|
continue;
|
|
|
|
for (a = 0; a < STM32_SDADEL_MAX; a++) {
|
|
int sdadel = (a * (p + 1) + 1) * i2cclk;
|
|
|
|
if (((sdadel >= sdadel_min) &&
|
|
(sdadel <= sdadel_max)) &&
|
|
(p != p_prev)) {
|
|
v = calloc(1, sizeof(*v));
|
|
if (!v)
|
|
return -ENOMEM;
|
|
|
|
v->presc = p;
|
|
v->scldel = l;
|
|
v->sdadel = a;
|
|
p_prev = p;
|
|
|
|
list_add_tail(&v->node, solutions);
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (p_prev == p)
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (list_empty(solutions)) {
|
|
pr_err("%s: no Prescaler solution\n", __func__);
|
|
ret = -EPERM;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int stm32_i2c_choose_solution(struct stm32_i2c_setup *setup,
|
|
struct list_head *solutions,
|
|
struct stm32_i2c_timings *s)
|
|
{
|
|
struct stm32_i2c_timings *v;
|
|
u32 i2cbus = DIV_ROUND_CLOSEST(STM32_NSEC_PER_SEC,
|
|
setup->speed_freq);
|
|
u32 clk_error_prev = i2cbus;
|
|
u32 i2cclk = DIV_ROUND_CLOSEST(STM32_NSEC_PER_SEC,
|
|
setup->clock_src);
|
|
u32 clk_min, clk_max;
|
|
u32 af_delay_min;
|
|
u32 dnf_delay;
|
|
u32 tsync;
|
|
u16 l, h;
|
|
bool sol_found = false;
|
|
int ret = 0;
|
|
|
|
af_delay_min = setup->analog_filter ?
|
|
STM32_I2C_ANALOG_FILTER_DELAY_MIN : 0;
|
|
dnf_delay = setup->dnf * i2cclk;
|
|
|
|
tsync = af_delay_min + dnf_delay + (2 * i2cclk);
|
|
clk_max = STM32_NSEC_PER_SEC / i2c_specs[setup->speed].rate_min;
|
|
clk_min = STM32_NSEC_PER_SEC / i2c_specs[setup->speed].rate_max;
|
|
|
|
/*
|
|
* Among Prescaler possibilities discovered above figures out SCL Low
|
|
* and High Period. Provided:
|
|
* - SCL Low Period has to be higher than Low Period of the SCL Clock
|
|
* defined by I2C Specification. I2C Clock has to be lower than
|
|
* (SCL Low Period - Analog/Digital filters) / 4.
|
|
* - SCL High Period has to be lower than High Period of the SCL Clock
|
|
* defined by I2C Specification
|
|
* - I2C Clock has to be lower than SCL High Period
|
|
*/
|
|
list_for_each_entry(v, solutions, node) {
|
|
u32 prescaler = (v->presc + 1) * i2cclk;
|
|
|
|
for (l = 0; l < STM32_SCLL_MAX; l++) {
|
|
u32 tscl_l = (l + 1) * prescaler + tsync;
|
|
|
|
if ((tscl_l < i2c_specs[setup->speed].l_min) ||
|
|
(i2cclk >=
|
|
((tscl_l - af_delay_min - dnf_delay) / 4))) {
|
|
continue;
|
|
}
|
|
|
|
for (h = 0; h < STM32_SCLH_MAX; h++) {
|
|
u32 tscl_h = (h + 1) * prescaler + tsync;
|
|
u32 tscl = tscl_l + tscl_h +
|
|
setup->rise_time + setup->fall_time;
|
|
|
|
if ((tscl >= clk_min) && (tscl <= clk_max) &&
|
|
(tscl_h >= i2c_specs[setup->speed].h_min) &&
|
|
(i2cclk < tscl_h)) {
|
|
u32 clk_error;
|
|
|
|
if (tscl > i2cbus)
|
|
clk_error = tscl - i2cbus;
|
|
else
|
|
clk_error = i2cbus - tscl;
|
|
|
|
if (clk_error < clk_error_prev) {
|
|
clk_error_prev = clk_error;
|
|
v->scll = l;
|
|
v->sclh = h;
|
|
sol_found = true;
|
|
memcpy(s, v, sizeof(*s));
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if (!sol_found) {
|
|
pr_err("%s: no solution at all\n", __func__);
|
|
ret = -EPERM;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int stm32_i2c_compute_timing(struct stm32_i2c_priv *i2c_priv,
|
|
struct stm32_i2c_setup *setup,
|
|
struct stm32_i2c_timings *output)
|
|
{
|
|
struct stm32_i2c_timings *v, *_v;
|
|
struct list_head solutions;
|
|
int ret;
|
|
|
|
if (setup->speed >= STM32_I2C_SPEED_END) {
|
|
pr_err("%s: speed out of bound {%d/%d}\n", __func__,
|
|
setup->speed, STM32_I2C_SPEED_END - 1);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if ((setup->rise_time > i2c_specs[setup->speed].rise_max) ||
|
|
(setup->fall_time > i2c_specs[setup->speed].fall_max)) {
|
|
pr_err("%s :timings out of bound Rise{%d>%d}/Fall{%d>%d}\n",
|
|
__func__,
|
|
setup->rise_time, i2c_specs[setup->speed].rise_max,
|
|
setup->fall_time, i2c_specs[setup->speed].fall_max);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (setup->dnf > STM32_I2C_DNF_MAX) {
|
|
pr_err("%s: DNF out of bound %d/%d\n", __func__,
|
|
setup->dnf, STM32_I2C_DNF_MAX);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (setup->speed_freq > i2c_specs[setup->speed].rate) {
|
|
pr_err("%s: Freq {%d/%d}\n", __func__,
|
|
setup->speed_freq, i2c_specs[setup->speed].rate);
|
|
return -EINVAL;
|
|
}
|
|
|
|
INIT_LIST_HEAD(&solutions);
|
|
ret = stm32_i2c_compute_solutions(setup, &solutions);
|
|
if (ret)
|
|
goto exit;
|
|
|
|
ret = stm32_i2c_choose_solution(setup, &solutions, output);
|
|
if (ret)
|
|
goto exit;
|
|
|
|
debug("%s: Presc: %i, scldel: %i, sdadel: %i, scll: %i, sclh: %i\n",
|
|
__func__, output->presc,
|
|
output->scldel, output->sdadel,
|
|
output->scll, output->sclh);
|
|
|
|
exit:
|
|
/* Release list and memory */
|
|
list_for_each_entry_safe(v, _v, &solutions, node) {
|
|
list_del(&v->node);
|
|
free(v);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int stm32_i2c_setup_timing(struct stm32_i2c_priv *i2c_priv,
|
|
struct stm32_i2c_timings *timing)
|
|
{
|
|
struct stm32_i2c_setup *setup = i2c_priv->setup;
|
|
int ret = 0;
|
|
|
|
setup->speed = i2c_priv->speed;
|
|
setup->speed_freq = i2c_specs[setup->speed].rate;
|
|
setup->clock_src = clk_get_rate(&i2c_priv->clk);
|
|
|
|
if (!setup->clock_src) {
|
|
pr_err("%s: clock rate is 0\n", __func__);
|
|
return -EINVAL;
|
|
}
|
|
|
|
do {
|
|
ret = stm32_i2c_compute_timing(i2c_priv, setup, timing);
|
|
if (ret) {
|
|
debug("%s: failed to compute I2C timings.\n",
|
|
__func__);
|
|
if (i2c_priv->speed > STM32_I2C_SPEED_STANDARD) {
|
|
i2c_priv->speed--;
|
|
setup->speed = i2c_priv->speed;
|
|
setup->speed_freq =
|
|
i2c_specs[setup->speed].rate;
|
|
debug("%s: downgrade I2C Speed Freq to (%i)\n",
|
|
__func__, i2c_specs[setup->speed].rate);
|
|
} else {
|
|
break;
|
|
}
|
|
}
|
|
} while (ret);
|
|
|
|
if (ret) {
|
|
pr_err("%s: impossible to compute I2C timings.\n", __func__);
|
|
return ret;
|
|
}
|
|
|
|
debug("%s: I2C Speed(%i), Freq(%i), Clk Source(%i)\n", __func__,
|
|
setup->speed, setup->speed_freq, setup->clock_src);
|
|
debug("%s: I2C Rise(%i) and Fall(%i) Time\n", __func__,
|
|
setup->rise_time, setup->fall_time);
|
|
debug("%s: I2C Analog Filter(%s), DNF(%i)\n", __func__,
|
|
setup->analog_filter ? "On" : "Off", setup->dnf);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int stm32_i2c_hw_config(struct stm32_i2c_priv *i2c_priv)
|
|
{
|
|
struct stm32_i2c_regs *regs = i2c_priv->regs;
|
|
struct stm32_i2c_timings t;
|
|
int ret;
|
|
u32 timing = 0;
|
|
|
|
ret = stm32_i2c_setup_timing(i2c_priv, &t);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* Disable I2C */
|
|
clrbits_le32(®s->cr1, STM32_I2C_CR1_PE);
|
|
|
|
/* Timing settings */
|
|
timing |= STM32_I2C_TIMINGR_PRESC(t.presc);
|
|
timing |= STM32_I2C_TIMINGR_SCLDEL(t.scldel);
|
|
timing |= STM32_I2C_TIMINGR_SDADEL(t.sdadel);
|
|
timing |= STM32_I2C_TIMINGR_SCLH(t.sclh);
|
|
timing |= STM32_I2C_TIMINGR_SCLL(t.scll);
|
|
writel(timing, ®s->timingr);
|
|
|
|
/* Enable I2C */
|
|
if (i2c_priv->setup->analog_filter)
|
|
clrbits_le32(®s->cr1, STM32_I2C_CR1_ANFOFF);
|
|
else
|
|
setbits_le32(®s->cr1, STM32_I2C_CR1_ANFOFF);
|
|
setbits_le32(®s->cr1, STM32_I2C_CR1_PE);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int stm32_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
|
|
{
|
|
struct stm32_i2c_priv *i2c_priv = dev_get_priv(bus);
|
|
|
|
switch (speed) {
|
|
case STANDARD_RATE:
|
|
i2c_priv->speed = STM32_I2C_SPEED_STANDARD;
|
|
break;
|
|
case FAST_RATE:
|
|
i2c_priv->speed = STM32_I2C_SPEED_FAST;
|
|
break;
|
|
case FAST_PLUS_RATE:
|
|
i2c_priv->speed = STM32_I2C_SPEED_FAST_PLUS;
|
|
break;
|
|
default:
|
|
debug("%s: Speed %d not supported\n", __func__, speed);
|
|
return -EINVAL;
|
|
}
|
|
|
|
return stm32_i2c_hw_config(i2c_priv);
|
|
}
|
|
|
|
static int stm32_i2c_probe(struct udevice *dev)
|
|
{
|
|
struct stm32_i2c_priv *i2c_priv = dev_get_priv(dev);
|
|
struct reset_ctl reset_ctl;
|
|
fdt_addr_t addr;
|
|
int ret;
|
|
|
|
addr = dev_read_addr(dev);
|
|
if (addr == FDT_ADDR_T_NONE)
|
|
return -EINVAL;
|
|
|
|
i2c_priv->regs = (struct stm32_i2c_regs *)addr;
|
|
|
|
ret = clk_get_by_index(dev, 0, &i2c_priv->clk);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = clk_enable(&i2c_priv->clk);
|
|
if (ret)
|
|
goto clk_free;
|
|
|
|
ret = reset_get_by_index(dev, 0, &reset_ctl);
|
|
if (ret)
|
|
goto clk_disable;
|
|
|
|
reset_assert(&reset_ctl);
|
|
udelay(2);
|
|
reset_deassert(&reset_ctl);
|
|
|
|
return 0;
|
|
|
|
clk_disable:
|
|
clk_disable(&i2c_priv->clk);
|
|
clk_free:
|
|
clk_free(&i2c_priv->clk);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int stm32_ofdata_to_platdata(struct udevice *dev)
|
|
{
|
|
struct stm32_i2c_priv *i2c_priv = dev_get_priv(dev);
|
|
u32 rise_time, fall_time;
|
|
|
|
i2c_priv->setup = (struct stm32_i2c_setup *)dev_get_driver_data(dev);
|
|
if (!i2c_priv->setup)
|
|
return -EINVAL;
|
|
|
|
rise_time = dev_read_u32_default(dev, "i2c-scl-rising-time-ns", 0);
|
|
if (rise_time)
|
|
i2c_priv->setup->rise_time = rise_time;
|
|
|
|
fall_time = dev_read_u32_default(dev, "i2c-scl-falling-time-ns", 0);
|
|
if (fall_time)
|
|
i2c_priv->setup->fall_time = fall_time;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct dm_i2c_ops stm32_i2c_ops = {
|
|
.xfer = stm32_i2c_xfer,
|
|
.set_bus_speed = stm32_i2c_set_bus_speed,
|
|
};
|
|
|
|
static const struct udevice_id stm32_i2c_of_match[] = {
|
|
{ .compatible = "st,stm32f7-i2c", .data = (ulong)&stm32f7_setup },
|
|
{}
|
|
};
|
|
|
|
U_BOOT_DRIVER(stm32f7_i2c) = {
|
|
.name = "stm32f7-i2c",
|
|
.id = UCLASS_I2C,
|
|
.of_match = stm32_i2c_of_match,
|
|
.ofdata_to_platdata = stm32_ofdata_to_platdata,
|
|
.probe = stm32_i2c_probe,
|
|
.priv_auto_alloc_size = sizeof(struct stm32_i2c_priv),
|
|
.ops = &stm32_i2c_ops,
|
|
};
|