lkml.org 
[lkml]   [2018]   [Dec]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v2 1/3] spi: meson-axg: support MAX 80M clock
From
Date
Hi Neil,

On 2018/12/13 16:49, Neil Armstrong wrote:
> Hi Sunny,
>
> On 13/12/2018 09:39, Sunny Luo wrote:
>> The SPICC controller in Meson-AXG is capable of running at 80M clock.
>> The ASIC IP is improved and the clock is actually running higher than
>> previous old SoCs.
>>
>> Signed-off-by: Sunny Luo <sunny.luo@amlogic.com>
>> Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
>> ---
>> drivers/spi/spi-meson-spicc.c | 37 +++++++++++++++++++++++++++++--------
>> 1 file changed, 29 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/spi/spi-meson-spicc.c b/drivers/spi/spi-meson-spicc.c
>> index 7fe4488..b56249d 100644
>> --- a/drivers/spi/spi-meson-spicc.c
>> +++ b/drivers/spi/spi-meson-spicc.c
>> @@ -9,11 +9,13 @@
>>
>> #include <linux/bitfield.h>
>> #include <linux/clk.h>
>> +#include <linux/clk-provider.h>
>> #include <linux/device.h>
>> #include <linux/io.h>
>> #include <linux/kernel.h>
>> #include <linux/module.h>
>> #include <linux/of.h>
>> +#include <linux/of_device.h>
>> #include <linux/platform_device.h>
>> #include <linux/spi/spi.h>
>> #include <linux/types.h>
>> @@ -34,7 +36,6 @@
>> * to have a CS go down over the full transfer
>> */
>>
>> -#define SPICC_MAX_FREQ 30000000
>> #define SPICC_MAX_BURST 128
>>
>> /* Register Map */
>> @@ -120,6 +121,10 @@
>> #define SPICC_BURST_MAX 16
>> #define SPICC_FIFO_HALF 10
>>
>> +struct meson_spicc_data {
>> + unsigned int max_speed_hz;
>> +};
>> +
>> struct meson_spicc_device {
>> struct spi_master *master;
>> struct platform_device *pdev;
>> @@ -127,6 +132,7 @@ struct meson_spicc_device {
>> struct clk *core;
>> struct spi_message *message;
>> struct spi_transfer *xfer;
>> + const struct meson_spicc_data *data;
>> u8 *tx_buf;
>> u8 *rx_buf;
>> unsigned int bytes_per_word;
>> @@ -517,6 +523,9 @@ static int meson_spicc_probe(struct platform_device *pdev)
>> spicc->pdev = pdev;
>> platform_set_drvdata(pdev, spicc);
>>
>> + spicc->data = (const struct meson_spicc_data *)
>> + of_device_get_match_data(&pdev->dev);
>> +
>> res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> spicc->base = devm_ioremap_resource(&pdev->dev, res);
>> if (IS_ERR(spicc->base)) {
>> @@ -567,11 +576,9 @@ static int meson_spicc_probe(struct platform_device *pdev)
>> master->unprepare_transfer_hardware = meson_spicc_unprepare_transfer;
>> master->transfer_one = meson_spicc_transfer_one;
>>
>> - /* Setup max rate according to the Meson GX datasheet */
>> - if ((rate >> 2) > SPICC_MAX_FREQ)
>> - master->max_speed_hz = SPICC_MAX_FREQ;
>> - else
>> - master->max_speed_hz = rate >> 2;
>> + /* Setup max rate according to the Meson datasheet */
>> + master->max_speed_hz = min_t(unsigned int, rate >> 1,
>> + spicc->data->max_speed_hz);
>
> I think "rate >> 1" here depends on patch 3, either move patch 3 before this one
> or keep "rate >> 2" and change it back to "rate >> 1" on patch 3.
>
Yes, this change should be in patch 3.

>>
>> ret = devm_spi_register_master(&pdev->dev, master);
>> if (ret) {
>> @@ -602,9 +609,23 @@ static int meson_spicc_remove(struct platform_device *pdev)
>> return 0;
>> }
>>
>> +static const struct meson_spicc_data meson_spicc_gx_data = {
>> + .max_speed_hz = 30000000,
>> +};
>> +
>> +static const struct meson_spicc_data meson_spicc_axg_data = {
>> + .max_speed_hz = 80000000,
>> +};
>> +
>> static const struct of_device_id meson_spicc_of_match[] = {
>> - { .compatible = "amlogic,meson-gx-spicc", },
>> - { .compatible = "amlogic,meson-axg-spicc", },
>> + {
>> + .compatible = "amlogic,meson-gx-spicc",
>> + .data = &meson_spicc_gx_data,
>> + },
>> + {
>> + .compatible = "amlogic,meson-axg-spicc",
>> + .data = &meson_spicc_axg_data,
>> + },
>> { /* sentinel */ }
>> };
>> MODULE_DEVICE_TABLE(of, meson_spicc_of_match);
>>
>
> .
>

\
 
 \ /
  Last update: 2018-12-13 12:56    [W:0.042 / U:0.484 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site