From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from asavdk3.altibox.net ([109.247.116.14]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1h0mJ7-0006ED-50 for barebox@lists.infradead.org; Mon, 04 Mar 2019 12:03:00 +0000 Date: Mon, 4 Mar 2019 13:02:52 +0100 From: Sam Ravnborg Message-ID: <20190304120252.GC16532@ravnborg.org> References: <20190304113823.21535-1-s.hauer@pengutronix.de> <20190304113823.21535-5-s.hauer@pengutronix.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190304113823.21535-5-s.hauer@pengutronix.de> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [PATCH 4/6] ddr_spd: Add function to read eeprom To: Sascha Hauer Cc: Barebox List Hi Sascha On Mon, Mar 04, 2019 at 12:38:21PM +0100, Sascha Hauer wrote: > Signed-off-by: Sascha Hauer > --- > common/ddr_spd.c | 81 +++++++++++++++++++++++++++++++++++++++++++++++ > include/ddr_spd.h | 6 ++++ > 2 files changed, 87 insertions(+) > > diff --git a/common/ddr_spd.c b/common/ddr_spd.c > index 9394c57fa3..a878790550 100644 > --- a/common/ddr_spd.c > +++ b/common/ddr_spd.c > @@ -429,3 +429,84 @@ void ddr_spd_print(uint8_t *record) > printf("%02X", record[i]); > printf("\n"); > } > + > +#define SPD_SPA0_ADDRESS 0x36 > +#define SPD_SPA1_ADDRESS 0x37 > + > +static int select_page(void *ctx, > + int (*xfer)(void *ctx, struct i2c_msg *msgs, int num), > + uint8_t addr) > +{ > + struct i2c_msg msg = { > + .addr = addr, > + .len = 0, > + }; > + int ret; > + > + ret = xfer(ctx, &msg, 1); > + if (ret < 0) > + return ret; > + > + return 0; > +} > + > +static int read_buf(void *ctx, > + int (*xfer)(void *ctx, struct i2c_msg *msgs, int num), > + uint8_t addr, int page, void *buf) > +{ > + uint8_t pos = 0; > + int ret; > + struct i2c_msg msg[2] = { > + { > + .addr = addr, > + .len = 1, > + .buf = &pos, > + }, { > + .addr = addr, > + .len = 256, > + .flags = I2C_M_RD, > + .buf = buf, > + } > + }; > + > + ret = select_page(ctx, xfer, page); > + if (ret < 0) > + return ret; > + > + ret = xfer(ctx, msg, 2); > + if (ret < 0) > + return ret; > + > + return 0; > +} > + > +/** > + * spd_read_eeprom - Read contents of a SPD EEPROM > + * @ctx: Context pointer for the xfer function > + * @xfer: I2C message transfer function > + * @addr: I2C bus address for the EEPROM > + * @buf: buffer to read the SPD data to It is not obvious what buffer size to provide here. And if it happens to be SPD_MEMTYPE_DDR4 then we suddenly start to write data at offset 256 in the buffer. So maybe add a small comment that this should always be 512 bytes. Or even better 2 x SPD_PAGE_SIZE (defined to 256) > + * > + * This function takes a I2C message transfer function and reads the contents > + * from a SPD EEPROM to the buffer provided at @buf. Returns 0 for success or a > + * negative error code otherwise. > + */ > +int spd_read_eeprom(void *ctx, > + int (*xfer)(void *ctx, struct i2c_msg *msgs, int num), > + uint8_t addr, void *buf) > +{ > + unsigned char *buf8 = buf; > + int ret; > + > + ret = read_buf(ctx, xfer, addr, SPD_SPA0_ADDRESS, buf); > + if (ret < 0) > + return ret; > + > + if (buf8[2] == SPD_MEMTYPE_DDR4) { > + ret = read_buf(ctx, xfer, addr, SPD_SPA1_ADDRESS, buf + 256); > + if (ret < 0) > + return ret; > + } > + > + return 0; > +} > diff --git a/include/ddr_spd.h b/include/ddr_spd.h > index 051275141f..95d0eb04b6 100644 > --- a/include/ddr_spd.h > +++ b/include/ddr_spd.h > @@ -6,6 +6,8 @@ > #ifndef _DDR_SPD_H_ > #define _DDR_SPD_H_ > > +#include > + > /* > * Format from "JEDEC Standard No. 21-C, > * Appendix D: Rev 1.0: SPD's for DDR SDRAM > @@ -562,4 +564,8 @@ void ddr2_spd_dump(const struct ddr2_spd_eeprom *spd); > int ddr3_spd_check(const struct ddr3_spd_eeprom *spd); > int ddr4_spd_check(const struct ddr4_spd_eeprom *spd); > > +int spd_read_eeprom(void *ctx, > + int (*xfer)(void *ctx, struct i2c_msg *msgs, int num), > + uint8_t addr, void *buf); > + > #endif /* _DDR_SPD_H_ */ > -- > 2.20.1 > > > _______________________________________________ > barebox mailing list > barebox@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/barebox _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox