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i2c: at91: Convert to use struct i2c_timings

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Instead of using custom variables and parser, convert the driver to use
the ones provided by I2C core.

No functional change intended.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
Andy Shevchenko 2019-03-21 12:36:34 +03:00 committed by Wolfram Sang
parent 529766e0a0
commit 265bd824e1
2 changed files with 8 additions and 16 deletions
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23
drivers/i2c/busses/i2c-at91-master.c
View File

@ -43,16 +43,18 @@ void at91_init_twi_bus_master(struct at91_twi_dev *dev)
* Calculate symmetric clock as stated in datasheet:
* twi_clk = F_MAIN / (2 * (cdiv * (1 << ckdiv) + offset))
*/
static void at91_calc_twi_clock(struct at91_twi_dev *dev, int twi_clk)
static void at91_calc_twi_clock(struct at91_twi_dev *dev)
{
int ckdiv, cdiv, div, hold = 0;
struct at91_twi_pdata *pdata = dev->pdata;
int offset = pdata->clk_offset;
int max_ckdiv = pdata->clk_max_div;
u32 twd_hold_time_ns = 0;
struct i2c_timings timings, *t = &timings;
i2c_parse_fw_timings(dev->dev, t, true);
div = max(0, (int)DIV_ROUND_UP(clk_get_rate(dev->clk),
2 * twi_clk) - offset);
2 * t->bus_freq_hz) - offset);
ckdiv = fls(div >> 8);
cdiv = div >> ckdiv;
@ -64,15 +66,12 @@ static void at91_calc_twi_clock(struct at91_twi_dev *dev, int twi_clk)
}
if (pdata->has_hold_field) {
of_property_read_u32(dev->dev->of_node, "i2c-sda-hold-time-ns",
&twd_hold_time_ns);
/*
* hold time = HOLD + 3 x T_peripheral_clock
* Use clk rate in kHz to prevent overflows when computing
* hold.
*/
hold = DIV_ROUND_UP(twd_hold_time_ns
hold = DIV_ROUND_UP(t->sda_hold_ns
* (clk_get_rate(dev->clk) / 1000), 1000000);
hold -= 3;
if (hold < 0)
@ -89,7 +88,7 @@ static void at91_calc_twi_clock(struct at91_twi_dev *dev, int twi_clk)
| AT91_TWI_CWGR_HOLD(hold);
dev_dbg(dev->dev, "cdiv %d ckdiv %d hold %d (%d ns)\n",
cdiv, ckdiv, hold, twd_hold_time_ns);
cdiv, ckdiv, hold, t->sda_hold_ns);
}
static void at91_twi_dma_cleanup(struct at91_twi_dev *dev)
@ -772,7 +771,6 @@ int at91_twi_probe_master(struct platform_device *pdev,
u32 phy_addr, struct at91_twi_dev *dev)
{
int rc;
u32 bus_clk_rate;
init_completion(&dev->cmd_complete);
@ -794,12 +792,7 @@ int at91_twi_probe_master(struct platform_device *pdev,
dev_info(dev->dev, "Using FIFO (%u data)\n", dev->fifo_size);
}
rc = of_property_read_u32(dev->dev->of_node, "clock-frequency",
&bus_clk_rate);
if (rc)
bus_clk_rate = DEFAULT_TWI_CLK_HZ;
at91_calc_twi_clock(dev, bus_clk_rate);
at91_calc_twi_clock(dev);
dev->adapter.algo = &at91_twi_algorithm;
dev->adapter.quirks = &at91_twi_quirks;

1
drivers/i2c/busses/i2c-at91.h
View File

@ -21,7 +21,6 @@
#include <linux/platform_data/dma-atmel.h>
#include <linux/platform_device.h>
#define DEFAULT_TWI_CLK_HZ 100000 /* max 400 Kbits/s */
#define AT91_I2C_TIMEOUT msecs_to_jiffies(100) /* transfer timeout */
#define AT91_I2C_DMA_THRESHOLD 8 /* enable DMA if transfer size is bigger than this threshold */
#define AUTOSUSPEND_TIMEOUT 2000